Help me diagnose this problem 95 Blazer

[Ibetchuwontdoit]

Hello AF community!

I have been given a 95 S10 Blazer 2dr because the owner could not afford to have it put into the shop. Literally, GIVEN. Anyways, to start off the battery was as dead as it could be so I gave it a good 2 day charge and started troubleshooting. Here are some symptoms:

Problem cranking (acts like its not getting proper fuel, or maybe too much? However, I don't smell fuel like its flooding out)

IF, it cranks, it will idle very rougly and usually die shortly after

IF it doesn't die shortly after cranking, any attempt at using the gas pedal causes a rough/irregular throttle response usually followed by it dying.

The VERY first time I cranked it after charging the battery, it cranked perfectly and drove/idled as smooth as ice. I let it idle for about 30 minutes making sure it wouldn't overheat or anything else. Everything did fine, I killed it and cranked it again later THEN encountering the problems described above. It's been the same since.

So, some of my guesses (keeping in mind I'm not very familiar with these vehicles) some type of sensor (crank/idle), bad vacuum leak or a loose connection somewhere in the electronics. Looking for some type of confirmation before I waste money throwing parts at it.

Also, included a short video of what it's like trying to crank and running.
http://www.youtube.com/watch?v=U1nhDy3id40

[MT-2500]

Originally Posted by Ibetchuwontdoit

Hello AF community!

I have been given a 95 S10 Blazer 2dr because the owner could not afford to have it put into the shop. Literally, GIVEN. Anyways, to start off the battery was as dead as it could be so I gave it a good 2 day charge and started troubleshooting. Here are some symptoms:

Problem cranking (acts like its not getting proper fuel, or maybe too much? However, I don't smell fuel like its flooding out)

IF, it cranks, it will idle very rougly and usually die shortly after

IF it doesn't die shortly after cranking, any attempt at using the gas pedal causes a rough/irregular throttle response usually followed by it dying.

The VERY first time I cranked it after charging the battery, it cranked perfectly and drove/idled as smooth as ice. I let it idle for about 30 minutes making sure it wouldn't overheat or anything else. Everything did fine, I killed it and cranked it again later THEN encountering the problems described above. It's been the same since.

So, some of my guesses (keeping in mind I'm not very familiar with these vehicles) some type of sensor (crank/idle), bad vacuum leak or a loose connection somewhere in the electronics. Looking for some type of confirmation before I waste money throwing parts at it.

Also, included a short video of what it's like trying to crank and running.
http://www.youtube.com/watch?v=U1nhDy3id40

Check for lose of proper fuel pressure.
What is fuel pressure?
Check for lose of spark to all plugs.
Doe it have good hot blue spark to plugs?
Any codes or check engine light ?

[Rick Norwood]

Do exactly what MT2500 said, check the fuel pressure. However, I would replace the fuel filter first. The fact that it ran a little tells me that the filter may be plugged up, especially if it has been sitting awhile. The pump could have easily picked up a bunch of sediment etc. from the tank and pushed it into the filter.

[Ibetchuwontdoit]

Originally Posted by Rick Norwood

Do exactly what MT2500 said, check the fuel pressure. However, I would replace the fuel filter first. The fact that it ran a little tells me that the filter may be plugged up, especially if it has been sitting awhile. The pump could have easily picked up a bunch of sediment etc. from the tank and pushed it into the filter.

I know how to replace the fuel filter, and those are cheap enough that it's no big deal but whats the best way to check the fuel pressure?

[Tech II]

You need a fuel pressure gage.....where the distributor is, you will find the metal supply and return lines coming up and going into the top of the engine....one of the lines will have a black cap(supply line)...remove the cap and a schraeder valve(just like a tire bicycle valve) is uncovered.....you screw the gage in here.....turn key on then off....wait several seconds....then repeat several times to get the max reading....the reading should not drop, and should be at least 60psi....

[LarryGLack]

Just some things I have found on my 92 s-10 with the vortac 6. The fuel pressure when running at idle is about 62 pounds. As you increase throttle it goes up to about 68 lbs. if you are loading it as much as possible without dropping out of overdrive it will be 70 lbs. This might not help if you cant get it on the road. I used an oil pressure gauge connected with the valve core removed from the test port. I already had one lying around and it was just for testing. Not something I'd do for long-term. While you have the filter out connect the oil pressure gauge to the line from the tank. The pressure on a new no name pump was 100 lbs. BUT I had replaced it only 20K miles ago (then it died after sitting 6 months with a full tank). I read on this forum they didn't last long. I returned the replacement I had already picked up and traded it in for a delco pump. It pumped up to 80 lbs. But it is supposed to last longer... When the pump is running connected to the system the pressure is controlled by the regulator in any case, as long as it will supply the needed range that is fine. My 92 will start if the pressure is 50 or above. I noticed it was not holding for several seconds with the key off, I put in some seafoam additive and it held! But then when the seafoam was used up it quit holding. Still runs with no problems but I will probably be working on it before it craps out.

[Rick Norwood]

Originally Posted by LarryGLack

The pressure on a new no name pump was 100 lbs. BUT I had replaced it only 20K miles ago (then it died after sitting 6 months with a full tank). I read on this forum they didn't last long.

Gee, was it an Airtex Pump? Good job putting in an AC-Delco.

[LarryGLack]

Sorry, I don't remember if it was an Airtex or what? I just went to the local auto parts store and picked one up. That was before I read about the reliability issues! Then I took it back and traded it in on a Delco....