need help bad s10 wont start

[mudhog]

ok so i have a 95 s10 blazer. we wear up in the mountains the other day elk hunting in the snow. on the way home the blazer in cruse control started slightly jerking and would also do it off cruse control just at an even throttle maintaining speed. then it got worse and worse and would barely run. just before getting home at a light i would have to hold the brake and hold the rpm at like 2500rpm just to keep it running. ok so what we have done put all new plugs wires cap rotor and also put in a new pressure regulator for the injection system. it then started ran for about 30 seconds and died. when i did get it restarted i had to pump the gas just to get it to start and keep it running. checked fuel pressure and it would prime to 65psi then drop fast. put old pressure regulator in and it started and ran for a day not right but it was drivable. then it got bad again and wouldn't run. i had took the new bad pressure regulator back and got a new one. put that in and again it ran for a few min and now wont start again. this time the pressure gauge when priming will go to 55-58 then slowly build to a little over 60psi. but wont start. also replaced the map sensor and the idle air control and the egr valve. still wont start but if you do happen to get it to start you have to pump it to keep it running

 

[y5mgisi]

I got $10 on a clogged fuel filter, bad fuel pump, or split hose in the tank. More likely the bad fuel pump.

 

[y5mgisi]

On second thought, pretty much sure fire that if its having fuel pressure problems, its probably the pump.

While cranking, does the fuel pressure stay that high?

 

[y5mgisi]

I obviously have no idea what im talking about, but on third thought, i wonder if you are pumping air. Obviously not all air but like air bubbled gas. So the fuel line can pressurizing but its not pressurizing with strictly fuel. No what im saying?

 

[79HeavyChevy]

I obviously have no idea what im talking about, but on third thought, i wonder if you are pumping air. Obviously not all air but like air bubbled gas. So the fuel line can pressurizing but its not pressurizing with strictly fuel. No what im saying?

That would be easy to test, just hold the schrader valve open and have someone turn the key on so it will prime the pump.

 

[mudhog]

forgot yes we did replace the fuel filter. and yes when cranking it has the same pressure we even pulled the spider injection and turned the key and it is firing out all the poppets

 

[zombiyjay76]

How did the fuel supply and return lines look?

 

[mudhog]

they looked good no leaks or any cracked lines or anything

How did the fuel supply and return lines look?

 

[y5mgisi]

Interesting. How does the spark look? Have you checked?

 

[mudhog]

spark is good and strong. if you put gas in the throttle body it will attempt to start

Interesting. How does the spark look? Have you checked?

 

[y5mgisi]

I still suspect something with the fuel system then. And my money still says bad fuel pump.

 

[mudhog]

im leaning that way to just didnt want to spend another $80 to find out its not the problem

I still suspect something with the fuel system then. And my money still says bad fuel pump.

 

[chicken joe]

i had a 95 s15 jimmy with 4.3l v6 sequential port fi, under the hood it looks like a corvette -2cyl., that did the same thing.

your spider injector or the wire harness for spider injector is shot. i put 213,000 miles on my jimmy and replaced the injector 3 times and one harness, the last time the harness went out on me i hydro locked cyl 3, and bent a rod.

 

[y5mgisi]

If that turns out to be the case, definitely spring for the upgraded unit that converts it from a spider injector to a true multi port.

 

[mudhog]

ya i would do that for sure. my son just did that with his 99 tahoe and damn what a difference that made in his

If that turns out to be the case, definitely spring for the upgraded unit that converts it from a spider injector to a true multi port.

 

[chicken joe]

for the price of the injector you could probably convert it twice.

 

[mudhog]

i have a new fuel pump ordered should be here in the morning going to try that and see how it goes

 

[y5mgisi]

Good luck! FYI, autozone has told me that they will allow returns on any part. Just something to think about. Most places won't let you return an electrical part. I now sometimes use autozone as a troubleshooting source. I'll buy something, try it, and if that doesn't fix the problem, I'll return it and buy something else.

 

[mudhog]

good to know since that is where im getting the fuel pump from lol

Good luck! FYI, autozone has told me that they will allow returns on any part. Just something to think about. Most places won't let you return an electrical part. I now sometimes use autozone as a troubleshooting source. I'll buy something, try it, and if that doesn't fix the problem, I'll return it and buy something else.

 

[mudhog]

well it wasnt the fuel pump changed that and still dose the same thing