7 TBI, the L05 I believe. It will consistanly shut off when warm and shifting into gear. it turns over for a few seconds, then has a fluctuating idle until warm, once put in gear the idle speed lowers (no tach so not sure on rpms) and taking off from a stop it bogs out, stalls, sputters etc. TBI's generally run in the 12-20psi range but the pump is capable of producing 60-100psi Got it. Marine engines run under a heavy load constantly (much like trucks) but do not have transmissions. '91 TBI 350 surging at idle and stumbling at speed Howdy - My father in law's '91 Chevy was running poorly, so we put new plugs, wires, cap and rotor on it, and it's running better, but it it still surging at idle. I have TBI as well and lemme tell ya, its WEIRD. The thermostat was new with the rebuild. it has adaptive strategy to learn how to run right. Indmar 310 TBI running rich, rough and backfiring If the resistance is high when the engine has been warmed up, it's bad. It runs really really rough on start up, when the weather is warner it runs better, not good, just better. Mileage down from 13avg to around 8. was throwing code 33 so i replaced the map sensor with a new one. Yesterday I put Seafaom in tank and ran for 20 minutes. 2 liter and here is what is happening to it. When it is warm the lower radiator hose is quite a bit cooler than the top hose which makes me think the thermostat may not be doing its job. Locate 87 95 for sale here!. I’ve had a rough idle problem with the Chevy 350 engine in the van and haven’t been able to solve the problem for over a year now. Once the car has been running for a while and the engine is up to operating temperature I run into the following issue: When I stop at a traffic light the car goes into idle ok. The sensor is new but the connection is suspect. But as the engine starts fine cold and warm when re-started withing 3 minutes. This Tbi Adjustable Regulator is needed for stock and modified GM tbi engines. 86 Fourtrax 350 running rough when hot. it has a new aluminum radiator, new thermostat, new serp belt, new belt tensioner, new rad cap, and new hoses. Off-Road Forums & Discussion Groups > Chevy and GM > GM Standard IFS Trucks & SUV's > 93 350 TBI to run rough when the engine is at normal opertating temp. 0L Ford E-350, E-450, E-550, read this useful information:. I would say that is varies a few 100 rpm. The more pressure at the injector, the richer it will run because the injector is open a set length of time no matter what the pressure. As soon as I put it in drive it drops further to the 400 or 350/300 mark. The ECU or the coil gets hot and expands. ATK HP31 Chevy 350 87-95 TBI Base Engine 290HP, Call 866-721-2315 to Speak with an ATK Crate Engine Specialist. r/MechanicAdvice: This is more than a car repair forum! most of the older 305 had bad camshaft wear. Also you will notice a bigger gain. My 93 chevy truck with a 350 motor(TBI),will start right up and runs good now that i've changed the timming chain and gear and alot of other stuffm,but when warm the idle goes from 1000 rpms to100 rpms and just keeps jumping back and forth,please help. 4) on a 350 (5. In the "Old" days, that was a stuck choke. Rough idle, the problems started in the fall when the temp droped and as it gets colder the rougher the idle is and have to give it gas just to keep it running. I got it going again and by pumping the accelerator, I managed to limp home -- had to run a couple of stop signs, though, because it just flat would not idle at all. B&B HELP PLEASE! Ever since then I have noticed that the truck will run rough both at idle and under acceleration after it has run. I'm going to begin work on the carbs this week. The cooling system for the Chevrolet 350 engine consists of a water pump, a radiator and a thermostat. I plan on changing the fuel/water separator filter, clean the spark arrestor. 86 Fourtrax 350 running rough when hot. No black smoke, 02 is reading nicely, it fires up when warm, and has good power again. Fast Fuel TBI 4 Barrel High Performance Fast Fuel TurnKey or Fi-Tech 4 Barrel Fuel Injection System Turnkey Engine. Tools required are a multimeter, and a small blade or a knife to slightly nick a wire to expose the wiring inside. My 97 would drop an injector when cold, and it would come back when it was warmish, after I went heavy throttle. The problem prompted the publication of Technical Safety Bulletin 18-48-98. Re: 1988 350 TBI idles funny, stalls when put in gear, and accels rough Fixed! After rebuilding the fuel pressure regulator, new fuel filter, plugs and wires, I finally dropped a new fuel pump in and seems to be running like a champ. Hard for me to tell what the spray pattern of the injectors looks like. The GRAY wire labeled "Fuel pump Feed+" must be connected to the positive fuel pump power wire to energize the fuel pump. My Yamaha does not use a fan on the oil cooler, owners manual says to speed up the engine if the RED oil temp light ever comes on and engine has been running at slow speeds on very hot day. Intermittent Rough/Hunting Idle when warm. Chevy 350 Hard To Start When Hot Flooding I have a chevy 355 crate motor in my 78 Jeep cj7. 050 in the 180° range, its a tiny cam. The engine stalls when putting into gear and runs rough at low speeds. One of the most common problems is likely a rough running or poorly idling engine. In all three areas, it would have a negative effect on the way the engine runs, especially when the engine is idling. It's caused by a lack of spark which can be either the ECU's fault (on EFI cars), or the coil on pretty much any car. 2 liter and here is what is happening to it. IAC Idle air control valve cleaning 87-95 TBI 305 350 Sierra Silverado Caprice. After doing some checking online I see thermostat temperatures listed for the TBI engines from 160, 180, 192 and 195. 0 Diesel It runs rough and has loss of power 2005 6. If the IAC is not working warm or cold you'd generally see problems with stalling when warm, especially when shifting to drive or coming to a stop, and you might have no starts or hard starts. 2003-2007 6. In the "Old" days, that was a stuck choke. You may have noticed other sellers using a similar name offering similar products. If you want to live in a society that works for everybody and not just. Only at www. 0L Excursion, 2003-2007 6. was throwing code 33 so i replaced the map sensor with a new one. I’ve had a rough idle problem with the Chevy 350 engine in the van and haven’t been able to solve the problem for over a year now. Engine was replaced with a 350 TBI. Rough idle, the problems started in the fall when the temp droped and as it gets colder the rougher the idle is and have to give it gas just to keep it running. 7 TBI / Runs rough after installation of new fuel injectors and throttle body rebuild kit 3 Answers I have done a rebuild kit on my throttle body. Re: 350 Mag MPI rough idle when cold I'm not sure of the type of engine but there is a Motorola logo where the plugs connect to the engine. My 1991 Chevy Silverado starts up ok, but has a rough idle until it warms up. It'd start running rough, new wires cleared it up. 0 4 cyl mercruiser overheating at high rpm/hot water going out intake; 3. My chevy 1987 chevy Scottsdale with a 350 tbi sometime runs smooth then sometimes runs like its running with half the power or less like it has bad gas or something. Thanks for clearing me up. 7L 350 Mercruiser Stalls when warm?? something I failed to mention, the boat runs well until it warms up. This Tbi Adjustable Regulator is needed for stock and modified GM tbi engines. I have osteoarthritis, arthritis, fibromyalgia and just joint pain everywhere. Truck runs pretty good when first cranked (cold), but after driving about 3 miles, starts to spit and sputter like it's out of gas and will not go over 35 mph. Figured needed new plugs and wires. I have a couple of issues with it, and I'm looking for some suggestions. Once the motor is warm (350 tbi) the idle wants to surge. if it can make GM TBI run on an old tractor engine. 3 powerstroke, when i first start it when its cold it runs real rough and the check engine light comes on, then after about 20 seconds it smoothes out and the light goes off. Chevy 350 5. Although it runs when cold started, the engine "hunts" in RPM and engaging the tranny (700r4) will occaisionally cause it to die. Magazine testers pro-the gaspers by omitting perfor-: figures, and any machine which struggle. 7L) engines. After i drive it for 10 minutes the check engine light will come on but it still runs the same as when i baught the truck. Hello, I have recent freshened up my Holley 4160 600cfm carb. They routed them between the block and the firewall. If, when warm, the idle seems to hang when blipping the throttle, the pilot circuit is too lean. The 02 sensor was reading lean and it was lazy to cycle, so I replaced it and the plugs, and it runs great now. The engine stalls when putting into gear and runs rough at low speeds. 7 tbi run like a bag of sh*t only after it got warm from a lazy o2 sensor. Hi i have a 94 chev k1500 350 tbi. This corrects the mating of the throttle body and intake. Now when its cold it runs really rough coughing and sputtering. dont think it went to engines that new but possible. once the engine gets warmed up a little then it runs great. Most of the carburetors installed on the 350 use a single air/fuel mixture screw, while some carburetors use two. Still no power in drive, any suggestions. The hot edges can ignite the fuel after shut-down. I am planning to put a new crate motor in it but have been fighting a rough idle problem for a while. What would cause TBI engine to sputter, hesitate, skip and misfire/backfire Discussion in ' The Garage ' started by afroman006 , Dec 19, 2003. * Very well maintained, has 527 hours. Running very, down on power. MERCRUISER HORN WARNING SYSTEMS 90-898301003 JUNE 2007 Page 3 / 10 1989–1994 4. B&B HELP PLEASE! Ever since then I have noticed that the truck will run rough both at idle and under acceleration after it has run. 4 Engines 1985-91 (w/o the 4L60-E or 4L80-E transmissions): Our harness upgrades to the 1988-90 CK truck computer. Freeway trip home was problem free, except I got a code 45 (running rich). Again, I have a 1990 K5 Chevy Blazer with the 350 TBI. But once it's warm, it sputters, missess and backfires. Thanks for clearing me up. this problem happend suddenly and im not sure if it is a cap&rotor or timing chain. Rough idle, the problems started in the fall when the temp droped and as it gets colder the rougher the idle is and have to give it gas just to keep it running. Despite 190,000 miles on the clock she has run perfectly until now, although quite heavy on gas. I had a TBI small. Serving our valued customers for over 30 years. Very easy to mount with one piece of flat steel and a couple of holes. A condition of running rough can be one of many factors. I swapped in to other used ones, and it ran better, but not great. 7L 350 MAG 7. This page is dedicated to the owners of these vehicles equipped with GM's dual point fuel injection (model 220 TBI). 0's, rough idle and stalls out when warm I have been following a number of threads on 6. I removed the elbow and used some new vacuum hose between the hard plastic line and TBI. The 2008 Ford F-350 has 7 problems reported for running rough. I have a 1990 K1500 5. **This would continued all day on a trip but didn't seem too bad as*problem was minor and. Engine wont idle/ Runs rough Volvo 5. Since the weather has gotten colder, the truck idles worse when first started. Engine do NOT throw any computer code. i have a tbi 350 out of a 90 suburban in my jeep. Since the weather has gotten colder, the truck idles worse when first started. Warm the bike up and turn the mixture screw to where you get the highest RPM. My 350 engine idles very rough, as if some cylinders were hitting harder than others or some are intermittently missing? Just above idle the engine smooths out and performs well. Hi Everyone, new to the forum. is, the worse the truck runs. In all three areas, it would have a negative effect on the way the engine runs, especially when the engine is idling. 0x1 v250 Advanced $0D. When theres a vacuum leak the engine is running lean and rough. However, the complaint from the driver was a lack of power. IAC Idle air control valve cleaning 87-95 TBI 305 350 Sierra Silverado Caprice. Sometimes, a TBI can cause changes in your mood and behavior. problem is that i cant seem to get the truck to idle or run correctly. ) Sharp edges on metal parts in the combustion chamber. Theres no reason to do it all at once except for you will have it off and its better to get it over with. I have changed the idle air Runs rough when cold - CarForum. I would say that is varies a few 100 rpm. Like the title says I have a 87 C30 w/454 TBI and 400th. Hard for me to tell what the spray pattern of the injectors looks like. 350 tbi rough idle no power. Or you could have a bad glow plug control solenoid, not stayig on long enough. Treating with Stiction Eliminator will clear out all of the stiction gumming your injectors. It runs awful until up to operating temp and still lacks power then. If I try to crank it up right away it would catch but would immidiately die. Re: 87 Chevy 350 TBI low Idle issue I had the same problem you described many years ago with my 87 350 FI 4x4 and after two mechanics played with everything with no results, I took it over and left it at the GM tech school and they found that the distributor shaft had become demagnitized. If you do lay into it it runs rough and backfires with no power. Looking for help please, 1998 5. 7, I am having some issues with the vehicle idling rough and. 0x1 v250 Advanced $0D. TBI's generally run in the 12-20psi range but the pump is capable of producing 60-100psi Got it. I have replaced plugs, wire, pick up coil, ignition coil, rotor and fuel filter. (SQUARE BODY TRUCK) Anyways, the engine was rebuilt fully in 2002. It passed Ca smog easily and I have been driving it. It is idling and then it almost dies, and then goes back to idle. Before it dies it never shows and sign of running rough. The engine has started to idle very high. I have a 95 Yukon, 350 tbi. Hello, I'm new to the forum. What causes 350 Chevrolet engine to miss after it warms Engine miss/running rough. I have looked at the fuel injectors while the truck is warm and idling, and it is very obvious that it is pumping in WAY too much fuel. Best TBI Mild to Hot Street! This is an excellent street machine engine, with a great OLD SCHOOL SOUND. I let it sit for 15/20 minutes and it starts and runs for 100 yards or so then bogs down again. 3/4 ton, 350 TBI engine with 125,000 miles. How your engine idles is a good indicator of its overall health; addressing the problem sooner rather than later and checking all potential causes is important. you are supposed to run the motor in all the way and set the idle to 550. Well, it didn't seem to idle rough until a few weeks after we bought it haha. Once it is warm, it runs good unless you try to accelerate real fast. cleaned everything up with throttle body cleaner. Within about 50 miles of home topped off (half tank) with 89 octane to see if it would help. 0L) and LO5 (5. Running cool (160 F) What I've done so far: 1. 1st Gen Ram Tech - 88 dodge ram 318 w/ tbi running rich - Looked down the throat of the throttle body at idlebutterfly valves appear to be wet all the time. More rough the ever. Stocker 350 like you describe should be fine even with a relatively small radiator like a Mustang/Falcon unit. Checked #8 again and this time it's hot like the others. HOWEVER, there is still a slight hesitation at initial acceleration. 7 surging, rough idle,cutting out 02 problem Wicked Spray. The commando project seems to be running hotter than I expect. this engine runs rough when cold misfires and so on, then when hot while running at higher speeds it backfires through the tbi unit. 350 TBI with turbo 350 trans. One of the most common problems is likely a rough running or poorly idling engine. As soon as she drops back down to idle, rough. got off hwy few eeks ago engine bogged down,kept stalling,I got stuck and was able to get it moving,running very rough 11. I’ve not narrowed my choice yet. I have a 95 Yukon, 350 tbi. 89 so it pretty much sounds balls-out at any speed over 25mph. If I try to crank it up right away it would catch but would immidiately die. 350 CHEVY HEADS BEST AND WORST. After doing some checking online I see thermostat temperatures listed for the TBI engines from 160, 180, 192 and 195. Best TBI Mild to Hot Street! This is an excellent street machine engine, with a great OLD SCHOOL SOUND. If you turn one injector off it won’t run for poop. It then bogs and backfires 2 Answers. 0L with a Ford B303 cam, GT40 heads w/ 1. Relationship between temperature and running OK, rough idle at start and missing which clears itself, all point to fuel air mix too rich. 2L, and 502 MAG Models 1989–1994 Carbureted Engines both Sterndrive and Inboard 4. Rough weather hit a few days after the install and I had to wait for spring to. how much fuel pressure does the pump need to put out? have to work the pedal to keep it running! seems like it running out of gas to me… i give up! just runs good for a second then dies then starts right up run for a. 0 liter mercruiser running rough at high rpm; 3. These sharp edges also have a few sources. As soon as she drops back down to idle, rough. I have a 97 7. Mileage down from 13avg to around 8. I have a 87 K5 stock 350 with TBI. Boat has been running fine, then last weekend I came back to idle after pulling a rider and the boat stayed up at ~1500 RPM. This xdf covers all of the original applications of the code. but after a couple of mins it straitens out and runs great however it is running rich and im only getting 8 mpg. 4) on a 350 (5. once the engine gets warmed up a little then it runs great. If the timing is RETARDED, the engine will run hotter; try advancing the timing. 7L TBI Mercruiser with Bravo 3 drive on a Sig 260. 2L, and 502 MAG Models 1989-1994 Carbureted Engines both Sterndrive and Inboard 4. Again, runs smooth at idle and even Revs smoothly but only when the truck is in park. There are several reasons why this happens - some major and some minor. "1994 Mastercraft 190 Prostar Indmar 350 V8 TBI No fuel prime when trying to start after skiing sometime 2-3% of the time? New fuel pump last year, new fuel filters, runs great 98% of the time start right away the first time. When it is warm the lower radiator hose is quite a bit cooler than the top hose which makes me think the thermostat may not be doing its job. Here is problem: The engine has alot of power, shifts smooth ect. 86 Fourtrax 350 running rough when hot. afroman006 1/2 ton status. Well, it didn't seem to idle rough until a few weeks after we bought it haha. 0x1 v250 Advanced $0D. it has 186k on it. it has adaptive strategy to learn how to run right. My chevy 1987 chevy Scottsdale with a 350 tbi sometime runs smooth then sometimes runs like its running with half the power or less like it has bad gas or something. Once it dies I smell some nasty fart smell or something rotten. The check engine light is not on. I own a 1987 Chevrolet R10 pickup with a 5. ) Sharp edges on metal parts in the combustion chamber. As soon as she drops back down to idle, rough. Discussion in ' Chevy Truck Talk & GM News ' started by Mowerwolf , Nov 22, 2017. My TBI 454 has been running rough. Its been fine for years untill 5 days ago. $350 DELIVERED. Shaveings fly. I put the TBI on the 350 with an edelbrock in take and a adaptor plate to put the TBI on the 4 barrel in take. Still no power in drive, any suggestions. This corrects the mating of the throttle body and intake. Today we are launching the most ambitious and radical campaign our country has ever seen to bring real change to our country. It could still be missing but I don't know. Not sure but in my part of Western KY our biggest farmer puts out about 15,000 acres and would have to spend more time on the road than in the field to do a 1,000 per day. 7L Running rough when warm. 0) is the same as a 350 (5. Symptoms: 1. The purpose of this article is to highlight some of these common problems and how to fix them, so your mighty "Five-Oh" runs just as good, if not better than it did during the Reagan/Bush Sr. It runs fine but when under slightest load (like disengaging clutch 1/2/3rd gear) it bucks/surges horribly. Possible intake manifold gasket problem. Warm the bike up and turn the mixture screw to where you get the highest RPM. it has 186k on it. The TPS is one of the main sensor inputs on a TBI (speed/density) type system. Now when its cold it runs really rough coughing and sputtering. I have a couple of issues with it, and I'm looking for some suggestions. 3 powerstroke, when i first start it when its cold it runs real rough and the check engine light comes on, then after about 20 seconds it smoothes out and the light goes off. When I start it cold it surges and idles poorly to the point of almost dying until it warms up then it idles fine and it seems to run like it should. need ideas This truck originally had a 400 in it which as I understand it they were hot running motors due to the thinner bores. It will start and run up to about half throttle and then it starts to miss. 5 L) Straight-4 piston engine built by the Pontiac Motor Division of General Motors from 1977 to 1993. Starts and runs/idles rough until you accellerate some the it smooths out and runs like it should. Boat has been running fine, then last weekend I came back to idle after pulling a rider and the boat stayed up at ~1500 RPM. Published Dec 7th, 2015. When it is warm the lower radiator hose is quite a bit cooler than the top hose which makes me think the thermostat may not be doing its job. '91 TBI 350 surging at idle and stumbling at speed Howdy - My father in law's '91 Chevy was running poorly, so we put new plugs, wires, cap and rotor on it, and it's running better, but it it still surging at idle. The more pressure at the injector, the richer it will run because the injector is open a set length of time no matter what the pressure. I'm running a Ls2 carburetored motor with Brian Tooley stage 4 cam, ported and polished heads and intake by Kimm Barr in Garland, Texas. 2003-2007 6. new 350 rebuild running hot!! I rebuilt a sbc 350 in my new to me pick up last fall. 1994 1500 5. She recently completed a grant that examines PTSD and co-morbid conditions in OIF/OEF female veterans, and one that examines mild TBI and PTSD in OIF/OEF veterans. I'm still running the same tunes as I was with the stage 1 injectors, but I gues idle ICP could be the issue. I have a 95 Yukon, 350 tbi. In all three areas, it would have a negative effect on the way the engine runs, especially when the engine is idling. The last few mornings it's been around 25-30 degrees, I go out and start my truck to let it warm up and the exhaust just reeks of gas. 2L, and 502 MAG Models 1989–1994 Carbureted Engines both Sterndrive and Inboard 4. but is it really worth keeping and building up? or should i leave it alone? or get a new engine?. remove valve covers. if its the camshaft you will notice little movement on the rocker arm. MERCRUISER HORN WARNING SYSTEMS 90-898301003 JUNE 2007 Page 3 / 10 1989–1994 4. SN's Vinnie Iyer weighs in with lineup advice and NFL DFS picks ahead. I can't think of any problem with the ignition system. 7L 350 TBI Surging which im hardly giving it any throttle that it runs rough, but going forward it dont seem to surge as bad as when it was warmer out. Boat has been running fine, then last weekend I came back to idle after pulling a rider and the boat stayed up at ~1500 RPM. It has an edelbrock performer package (cam/intake/carb) it has a mechanical fuel pump. Never have seen the Yamaha or the Honda oil temp light come on continuously when operating the engine on hot days though. I am pretty sure the TBI™ 350 engines use a cam with high. 0 tbi motor has low compression and runs a low operating temp. It runs awful until up to operating temp and still lacks power then. When this happens it's like a "erratic electrical component operation" and the lights and radio flicker but do not reset or shut off. So no shift points. After another 20 seconds its rough again, then smoothes back out. When you unplug it, the ECM goes into "limp home" mode with a pre-set series of tables designed to have the best shot at keeping the engine running until you can get somewhere safe to fix it (a garage). Theres no reason to do it all at once except for you will have it off and its better to get it over with. but it runs great when accelerating or about 60mph and faster almost like nothing is wrong with it. net - Car Forums, Automotive News and Community. It will consistanly shut off when warm and shifting into gear. 2L 502 MAG Horn Output Possible Cause Corrective Action Engine Usage Available For Consumer Key on, engine not running. xdf 16168625, 16196395 and 16197427 PCM with $0D Mask. How your engine idles is a good indicator of its overall health; addressing the problem sooner rather than later and checking all potential causes is important. On a tune up with the cap and rotor being replaceda good rule of thumb is to replace the plug wires the same timeone less headache later on. 91 350 TBI rough idle and no power at all with a new rebuilt 350 tbi. ? I have a mid-70s 350 truck (txb code) with 327 heads (camel hump) it has sat almost 10 years D. 350 chevy runs rough (like missing cyls) but all plugs fire. Acceleration is good. When it's sat for a while and I start the engine, it idles at about 1200rpm for the first couple of minutes, then drops down to about 900rpm, and a little while after that drops down to 6-700rpm where it idles at when warm. Check out our three recipes to pick up real power. 7) by changing the injectors and the use. It runs really really rough on start up, when the weather is warner it runs better, not good, just better. I didn't get home till dark last night so I wasn't able to run the saw. Again, I have a 1990 K5 Chevy Blazer with the 350 TBI. 350 chevy runs rough (like missing cyls) but all plugs fire. I am almost out of ideas. Today you don't have a choke so it is either a sensor or the brain saying, "I'm cold" and wants another log on the fire. Once on plane and up to speed, its hard to tell that it is running rough, but it is. runs rough, hard start after refueling, tsb 11-8-8 audible click noise, and/or dtcs p017x, p0316, p0442, p045x, p144a, p1450, p1a0c, built on or before 11/1/2010. That should put the truck into open loop. com > Models > Jeep CJ Forum > CJ with 350 TBI running hot HW speeds Last 10 miles or so is where it really starts to run hot. 350 SBC -- How Hot is Too Hot? I was running warm in traffic last year at the Roundup, so I grabbed a $20 12" fan from one of the vendors. Even during driving it would lose power. In my case, about 20 seconds after a carb jet plugged at 3000 rpm and I noticed a power drop off until the motor seized with a broken piston. Engine stalls when you come to a stop, after the engine warms up. This is a discussion on 1996 buick roadmaster runs rough when idling and skipping within the General Help forums, part of the LSx Technical Help Section category; I have a 1996 Buick Roadmaster 350 LT1 5. I have a chevy 355 crate motor in my 78 Jeep cj7. 0L Excursion, 2003-2007 6. It passed Ca smog easily and I have been driving it. A customer with a Mazda 626 and a four-cylinder engine had a very rough engine idle. Re: 1988 305 TBI Runs rough for 5 seconds When you just changed the sensor did the gauge say the car was running cooler. 0) is the same as a 350 (5. I am still on the fuel/air mix. If you have the throttle just barely open it will smooth out until it upshifts then it does it again until the rpms build. Acceleration is good. Starts and runs/idles rough until you accellerate some the it smooths out and runs like it should. Fuel Pump The ECM sends a signal to the Fuel Pump Relay to turn on the fuel pump. left it alone because it's too cold out. After it warms up if it is sitting idling it runs rough as crap and then dies. 7 TBI (3 year old Jasper engine - 20k miles). Here are the summit racing air filters that I use and recommend. It is of vital importance that the cooling system work properly, as a cooling problem can lead not only to an engine which overheats, but also to more serious problems such as a damaged head gasket or a cracked. New Quality Hand-Built in America Chevy 350 Small Block Engines for Sale for Your Street Performance Hot Rod, Muscle Car, or Classic Truck! Available in Short Block, Long Block, and Custom Crate Engine Packages. Requirement for the 50 to 52 mm throttle body: the intake manifold has to be counter bored to 52 mm intake bore size. but is it really worth keeping and building up? or should i leave it alone? or get a new engine?. Most of the carburetors installed on the 350 use a single air/fuel mixture screw, while some carburetors use two. It would suddenly go away after a few minutes like someone threw a switch, a timed thing, not related to temperature, speed or anything else I could figure out. 89' 1500 350 TBI rough running, any help appreciated a few weeks ago the truck started running rough when taking off as of late is that it does it far worse.