I just picked this jimmy up for cheap, needs a little bit of work but one problem has me guessing:
On occasion, really not too often when I come to a stop in traffic it will just die. No sputter no rough idle just as if I turned the key. Note this has never happened while in Park only while stopped in Drive. About half the time it will start right up and go, the other half I have to crank for a second or two, stop for a second then crank again and it fires right up.
Now, when this happens I can leave it in Park and it is good. If I move it back to drive and don't immediately start going, it will often die again. But once I'm going it typically will not have that problem for another day or so.
There is no CEL.

Aside from this, it runs and drives real smooth.
Ideas?

 

Bump?

 

I would check your fuel pressure.
What engine?

 

Yeah the fuel pressure is where I was leaning as well.
I haven't really looked at anything, but I will be replacing the spark plugs just because I can't buy a car and not do that...fuel filter is getting replaced since it is so easy to reach.
Problem is, I searched forever the other day for a fuel test port (Schrader valve) and found nothing...asked the guy at GM and they said there isn't one -_-
It is the 4.3 TBI, Z model.


I've searched for adapters all over town that will allow me to tap into the fuel line and take a pressure reading but no dice. What do you guys do for these models? o.O

 

I honestly have no idea how to test the fuel pressure on a TBI model. I have only had and worked on W CPI models. Hopefully someone can chime in on that.

 

Adapters are available that will go between the TBI unit itself and the stock lines. A mechanical gauge right into the adapter is what is done most of the time. Google "TBI fuel pressure gauge" and you'll get a lot of results.

 

Awesome; found one on ebay for $19 shipped.


To update:
Yesterday it started getting really bad - began dying not just when stopped, but if I slowed down too much - and also began dying in N or P unless I gave it gas.
So I:
*Replaced all the plugs, old ones didn't look too bad. Popped off the distributor cap, all the contacts were corroded pretty bad. Took the rotor off and saw that the distributor itself is completely rusted - not even sure how it carried current to the rotor.
*Put on a new cap/rotor.


I have a new distributor sitting in the Jimmy waiting for somebody to come watch the baby so I can swap it out.


Effed one of the wires when pulling the plugs - they were pretty new, but now I guess I'm replacing the set anyway. For now I just replaced the one (Was getting dark, and also had to put a new positive battery terminal clamp on the girl's '06 Camry that snapped off due to corrosion)


*Replaced the fuel filter.


After doing what I've done so far - it improved a lot, and seems to have picked up some power, but still dies just not as often. (Still dies in N and P sometimes)


While I'm not big on throwing parts at a problem 'till it works - this is all mostly pretty basic maintenance I'd be doing either way, except the distributor assembly...but that clearly needs replacement anyway.


I suppose if this doesn't fix the problem, I've still got fuel pump and fuel pressure regulator to look at...anything else I might be missing?

 

Fixed:


Went to put in a new rotor, picked up a new ignition coil while I was out since it was cheap. New parts are good parts.


Threw 'em in..then after 2 hours thinking I effed up the timing (Wouldn't start, rotated the distributor a few diff directions...nothing...bumped the ignition about 20 times until the timing mark showed 0 degrees and re-aligned...nothing) only to realize I forgot to plug the two plugs back into the coil after replacing.
Then it fired back up.
Then I put the distributor back to where it was supposed to be.
Then it fired back up and didn't spew smoke everywhere.


Now it purrs like a kitten, doesn't die ever, has a much better throttle response.
And I can count on the ignition system not failing me for a long long time =D