1989 Chevy 3500 5.7l Which Stalls Once Warm

merlin969 · September 18, 2011

Hello

I have a 1989 Chevy 3500 2wd crewcab 4sp (3sp w granny gear). The vehicle cranks fine and drives fine until it reaches operating temp. Once the vehicle reaches operating temp about 175 she cuts off. Once she cools off, she'll crank right back up until she reaches operating temp again. I've changed the EGR valve, Temperature sensor, control module, plugs, new injectors. I have included a copy of data i pulled from the pcm. Please let me know if anyone has any ideas.

Douglas,

1989_Chevy_3500_57_4sp.txt

merlin969 · September 18, 2011

FYI, the txt file headings dont exactly line up with the columns, I have it in excel but I wasnt able to post it. I can email it if it would help.

merlin969 · September 19, 2011

anyone have any ideas? any at all?

ChevyTech77 · September 19, 2011

That file doesn't work for me but what is your 02 sensor doing? Are the grounds at the thermostat housing devided between both studs or all on one? What do you loose, when the concern is present, spark or fuel?

merlin969 · September 19, 2011

The o2 sensor stays right around .46 when its running, once it cuts off and im trying to crank it it'll drop down and be all over the place .1 to .35 for the most part. Vacuum is around 16 inches. I'm losing the fuel. Today it idled for 30 minutes in the yard but wouldnt get hot enough to cut off until I drove it around the block. Looks like about 177 to 178 degrees is where she dies. I've got one ground on the AC bracket and one on the alternator bracket right beside the waterneck. The both are tight and seem to be working as they should. I thought I had this problem licked when I changed the Temp sensor. I drove it around for a couple days and it seemed fine. Then it sat for a couple months and its doing it again. Here is something I just noticed, when I turn the key to on(before I actually try to start the engine) I dont get a check engine light. Shouldn't it come on and then go off once its cranked? I do get good data with my laptop and a odb1 usb connection.

Doug