STALLING PROBLEM...91 Gmc Jimmy s-15,

.STALLING PROBLEM.
91 Gmc Jimmy s-15, 4.3L throttle-body inj. 2 wd, 152K. Auto.

Car will start and runs great for 7-10 minutes. Then sputters and dies. Replaced plugs,
cap, rotor. Pulled in-line fuel line at t-body & it's pumping like crazy. Also...when it
dies, I can still see fuel squirting into the t-body. After it dies, I check for
fuel...plenty of fuel & plenty of spark> This makes no sense? I have spark /fuel, &
compression, yet it dies every 7-10 minutes. I did replace the fuel pump and the filter
not to long ago. Whassup???
Thanks,
jon

 

you can try looking at your ckp sensor, and o2 sensors. i would be interested to know if it dies right when it goes into closed loop mode

 

ckp= ???

"crank position sensor"???

 

Might be instructive to check for any codes if you haven't already. It's an easy DIY on older GMs stuff:

http://www.troublecodes.net/GM/

 

After searching...the EGR valve could be sticking open creating a vacuum-like leak?
Where's the EGR on a '91 4.3L t-body inj'd.

 

Excellent link!!!!
I've been lookin' for that!!
Thank you very much!!
I will do that tonight after work!!

Me so happy (for now)

Where is the "Locate Data Link Connector (DLC), see image below"

 

You also may want to look at your cat convertor,very common to plug up,if the ckp or cam sensor dosent fix it loosen the exhaust at the manifolds (3 muts on each side),and see if that helps,i went through major trama with one at the shop,and thats what it was,could watch the timing retard on the scan tool,then die,the exhaust will back up,then FORCE the egr valve open,the knock sensor picks up a ping and retards timing,always chek the obvious first,and at the time it felt like plenty of exhaust was coming out the tail pipe,i would check that first good luck!

 

I followed the instructions.
I got:
FLASH, pause, FLASH, FLASH = code 12

There is NO code 12!!
The codes start with 13!!!

 

Thank you.
I am an 'ol carburater guy and FI drives me nuts!!
I ran the truck again with timing light shining into t-body. It died at exactly 10 minutes again and had spark and fuel when it died.
I checked the code again and #12 flashed again. #12 doesn't exist in the trouble code info.
Where is the "CPK sensor,(Cylinder Position Sensor) located?
Cam sensor? location?
I will search AUTOZONE AND THE LIKE TO GET PICTURES OF THESE items so I can locate them.
I have lubed the 3 studs on the exhaust mani. downtube to follow your advice on the Cat/02 sensor as well.
thank you
jonny

 

The 12 code is just the computer saying hello. The code string starts and ends with 12, usually three times, with the faults in between, i.e. 12-12-12-34-34-34-42-42-42-12-12-12.

Lots of help here:

https://www.autozone.com/N,312755/in...cleSelect4.htm

 

I'd like to say more than "Hello" to the 'puter!!
Anywho, I cleaned the EGR valva as someone had said carbon could get in there.
Ran for 5 minutes this time before quitting. I had the timing light on the crank and it moved toward retardation when dying.
I then ran the codes again..12-12-12-15-15-15-12-12-12

15=Coolant temperature sensor signal indicates a temperature colder than -27? F for 30 seconds after the engine has been running for at least 30 seconds.

Hmmm. replace the Coolant temperature sensor??

Car is in my warm garage with the exhaust routed outside.

 

Yes, I would try a coolant sensor since you have a code for it. Also, first check connectors and wiring for any obvious signs of a problem. Had one go bad in my wrecker (350 Chevy motor) couple of years ago. Thought we had bad ignition module or coil and didn't check codes. Did a big "Duh!" after couple of hours of chasing our tails.

Keep in mind that you may have 2 sensors, one for computer and a separate one for the instrument panel temp gauge. On my 350 the ecm temp sensor is in the intake manifold and the gauge sensor on left side of block.

Not sure I was clear on the code thing. The 12 code indicates the computer is in diagnosis mode, i.e. giving you fault codes. If there ARE no fault codes you'll just get continuous "12"'s.

 

FIXED!!!
Tanks Tow Guy!!!!
Put a new sensor in and it ran for 35 minutes!!!!!!
You are an asset to this board!!
Thank you again.

Total cost= $24 (cap/rotor/plugs/dry gas)
Sensor was $14.61, but I traded a used clutch master cyl. for it at the parts store where I know the guy!!