Gmc Jimmy help

[BlazerLT]

Yes it will tell you everything and at least point to the problem area instead of you just fumbling around throwing parts at it.

It is a computer controlled vehicle with a code system to help in this situation.

No using it is pure repair arrogance.

[kmarkgl]

Your version of everything and mine are clearly different. I HAVE ACTUALLY HAD THIS PROBLEM. No matter how many times I scanned it, nothing would show up. OBD 1 does not look at everything. OBDII does. Probably what you are refering to is a '95 model vehicle. '94 and earlier Use OBD1 which looks at the sensors. The unit in question is not a sensor. It is a fuel injector. Trust me, I spent a year and a half trying to figure out what the problem was. I have provided all of the information needed to diagnose this particular component. By all means, don't replace it if it is not bad. Run the tests because this is an expensive piece, I have bought many of them. 10+

As far as throwing parts at a problem... I did that. I did that because the computer spit out a code that stated that the egr valve was faulty. This is also an expensive piece, about 160. So much for the computer being right about everything. All it was is carbon chunks getting trapped in the valve and holding it open (think that I have coverd this already) causing it to run like crap. The carbon was caused by the rich mixture from the raw fuel sitting in the intake from the leak. This being caused by a leaky regulator. I saw it leak so I KNOW that it was leaking.

Another symptom of the problem is hard starting. I would have to let mine crank for about five seconds before it would crank. I thought it was the fuel pump at first. As I learned more about the system I found out that it takes an extreme amount of pressure to open the poppets at startup. What I found out was that if the regulator blows it is not able to build the fuel pressure right away. If I remember right it takes around 60 psi to open the poppets. After the pump runs for an extended amount of time it will give enough pressure to open the poppets and start the truck.

I posted to this thread because I had to scrounge for the info on this system. This is an easy problem to diagnose once you know how to do it, and I have outlined that here. Basicly, check for fuel pressure. If with the key in the on position the pressure builds then starts to leak down you haave a leak somewhere. If the pressure dosn't reach near 60 psi, the truck will not start right away. Pulling the upper manifold off is very easy. I can pull mine in less than 5 min. Then it is a visable check. Raw fuel in the intake? Leak somewhere in the intake. Puddle of fuel on the passenger side then the regulator is leaking. Cycle the fuel pump again and watch the regulator. If it is leaking you will see fuel leaking out. If the puddle is on the drivers side then you have a fuel line problem. Probably not though becasue they are high pressure lines but anything is possible.

I have tried to be very clear on this issue. All of the information is here to check for the problem. I did not have this luxery when I had my problem. Heck the truck ran for a year and a half with no light on at all. So much for the computer telling you everything that you need to know. Computers are great. I build them in my spare time but they only see what you put into them. OBD2 is cool. If you have a miss, it will even tell you what cylinder it is.