Hello,I have a 1987 Chevy 1 ton work truck that has 350 TBI and i am having problems,over the year when i would crank it up and go down the road it would surge alittle but would clear up i a minute or so,well this morning i went to crank it up it cranked fine but started surging up and down and gets worse,when i try to give it gas it will die,but it will crank back up but as it trys to warm up it gets worse and shuts off,i was reading on this site and tried a few things,I took off the vacume line to EGR and sucked on it and it would not pull air so i guess fine,i tried to pull a code but it did not have one stored,anyway dont know which way i need to go from here,on the TBI standing at front looking left theres 2 items on the throttle body are they the IAC and throttle position sensor?,one has 3 wires other has 4 wires with a square plug and its in the back,..also the truck is stock...thanks eric
CK5
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1987 chevy 1 ton 350 TBI problems,surge and dies
- Thread starter esa
- Start date
trikstark5
1/2 ton status
My '89 Jimmy was doing the same thing. It would start surging and the more gas I would give, the worse it got. My problem ended up being the fuel pump not supplying adequate pressure and flow. I replaced the pump and filter and never looked back.
Hope this helps...
Hope this helps...
Hello Thanks for the reply,i have Dual tanks on the truck and a few years ago i put new pumps in them both,i flip the switch and it still does it,i can look into the Throttle body while it is running and give it gas it will put the gas into it fine,,,so i dont know,does it have a IAC valve? and if so where and can it be cleaned?
im had the same problem its pulling up map sensor and tps i replaced the tps and map sensor from a 4.3 tbi and ran fine for along time now its surging again only once in a while tho and and giving me the map code again...maybe try one of these. thirdgen.org has tons of tbi stuff and would probley be more usefull then this site....hope this helps....try thirdgen.org i found it very usefull
well still havent figured it out,here is what i have done so far,my uncle has a truck that he isnt using so i got parts off of it to test mine,i tryed MAP sensor didnt fix it,tried IAC didnt work,tried temp sensor didnt fix it,tighten grounds,i have new fuel pumps,i have changed fuel filter,tighten the TBI, took off the dis cap cleaned and looked ok,2 things i havent tried is oxygen sensor and the AIR valve,the motor is hard to crank and wont stay crank for 2 or 3 second's,if you give i Gas it Dies,i looked into the TBI and has i Believe alot of gas in the intake,there is NO codes stored in computer.and on the EGR i havent replaced it but the motor does not change if you pull off vaccume line, so not sure what else to look at??? any advise??
BLIDVL
1/2 ton status
I just had the same problem with my 89 TBI, replaced the same things you did still had problems, mine would'nt throw any codes either. It ended up being the distributor, it seemed fine just visually inspecting it but was definitely the problem. If you have another one laying around I'd swap it in and see what happens.
BLIDVL
1/2 ton status
I think the bushings were shot and it was bouncing the arc from the rotor around inside the cap,wouldn't throw any codes just the surging and misfiring. I was getting spark,and it ran, had the intermittent surging and under load stalling problems,then sometimes just plain wouldn't idle at all. It was hard to figure out because it really behaved like a bad EGR valve or vacuum related issue. I guess I'm lucky I have been gathering stuff to switch to TBI on my 75 and had a bunch of known good parts to try.
sounds like a bad EGR...
BLIDVL
1/2 ton status
It does sound like a bad EGR , I thought he wrote he had checked the EGR,if not definitely make sure it is working.
OK,i have done so more to it with NO luck,i replaced the wires,plugs,cap,rotor,and still it wont crank,it will fire alittle but will die,the old plugs i took out where ALL fouled out and some of my wires where bad but with all new stuff it still wont crank,dont coils go out all at once most the time?,i guess i can get a new EGR and try that,wondering if the oxygen sensor will not let it crank? or will a EGR valve not let the motor crank?, its really temping to just pull off the TBI and put a carb and a HEI Dis in,any ideas would be greatful, and i thank all who have already helped me...eric from NC
Two things to check. First, replace your coolant temp sensor. Two wire sensor right beside your thermostat housing with black and yellow wires. Those sensors fail to high resistance, making the engine controller think the coolant iis -40F and really lay on the fuel heavy to choke the engine. Costs around 20 bucks for a new one. Second, check your fuel pressure. If the regulator in the injector pod has failed, your injectors will be getting too much pressure applied to them, causing a very rich condition
OK,here is what i have done,i replaced the Temp sensor beside the T-stat housing and it didnt help it,i also installed a New Fuel pressure Regulator in the TBI Housing and it is still doing the same thing,on the fuel pressure i havent checked it but i have replaced both of my fuel pump few years back being i have Dual Tanks,i can switch to other Tank and still does it,it looks to me it my be Putting more Gas than should in T-Body but im not really sure on that.any ideas???
could have a fubared injector..... how are the spray patterns? spark plug readings?
i checked the injectors and they r fine and spray good,i also got a new EGR valve and a new EGR soloinoide and neither fixed the problem,,,could it be a Bad Prom or cal/pak chip???.theres not much left,i havent changed the oxygen sensor,it still does the same thing it will crank but wont run...
doubtful... it wont run at all now?
it will crank up for 2 seconds and die,its hard to crank and when it does its rough.this all happen over night,,,,one thing i have thought about is this,for the last year or so when i would crank it up in the morning it would run fine but now and then when i first started down the road it didnt wont to take the gas and the service engine light sometimes came on,but after a miniute or so it would clear up and run fine...i am going to order a service manual this week maybe that will shead somemore light on how to check the circuits and stuff...this is one of the most hardest things i have done..
alriight you where throwing me off with "crank", usually i refer to cranking as the spinning of the starter, once it starts, it's fired...
did you pull codes? it the check engine light came on, it threw a code... it really sounds like an EGR.. make sure you have the right index washer on the EGR if you replaced it..
did you pull codes? it the check engine light came on, it threw a code... it really sounds like an EGR.. make sure you have the right index washer on the EGR if you replaced it..
Sounds like distributor to me.
