I have a 1990 GMC sle-2 5.7 stalls out when temperatures reach normal
when the truck is cold it runs good but as
soon as it reaches normal temperature
room it wants to stall and have to wait
about 45 minutes for it to start back up and
runs good until it warms up again and it
stalls out please help
You need to find out if it is spark or fuel related, when it is in failure try spraying a little starter fluid in the intake, if it fires and runs for a little bit then it is fuel, possible fuel pump relay or the pump itself, checking for power at the pump for a few seconds when you turn on the key will tell you which one. If it doesn't run then it is spark, you actually have described a classic ignition module failure, runs when cold, when it warms up it quits running, so cut though things, have you ever replaced the ignition module or distributor pickup coil, if not now would be a good time to do so, you may want to price out a complete distributor as it maybe cheaper that purchasing the parts separately. Then think about when was its last tune up, plugs, wires, filters, etc.
it has a brand new fuel pressure regulator new distributor cap new wires new plugs still does it
Still could be ignition or fuel as I stated earlier. But you did rule out the tune up.
is there any chance it could be the engine control temperature sensor
It would throw a check engine light and it would still run, just not the best. Is there a check engine light on when it is running? You didn't mention it in your first post.
How about the control module under the distributor cap, or the coil.
yes the check engine light is on when it is running
Yes that is what I was telling you about if you have never replaced them.
Then pull the codes before doing anything, this rig you can get them using the paper clip trick and watching the flash out on the check engine light.
Looking for a Used Sierra C/K 1500 in your area?
CarGurus has 4 nationwide Sierra C/K 1500 listings and the tools to find you a great deal.
Search GMC Sierra C/K 1500 Questions
GMC Sierra C/K 1500 Experts