1989 Coupe, Engine Runs For 2 Seconds And Shuts Off

[juanway]

Drove vette from Denver to Taos, engine ran great, next day engine would start but run for 2 seconds, I found fuel filter plugged and pressure pop off connector just above fuel pump had moved enough to keep fuel from giving me full pressure going to F.I. Installed new fuel filter & pump and put a 1/4 inch submersible fuel hose with clamps where the pop off connector was. Engine would not idle until I closed the TB by backing off on the idle screw. so I let it run at 400rpm until it warmed up and the idle circuit kicked in and it idled smoothly at 600 rpm in drive. The throttle body was cleaned and a new IAC and TPS was installed pryer to going on trip is it possible the IAC or TPS may be Faulty and how do I check for proper setting of Both??? which one should be set first? No check engine light came on. I drove back to Denver Pulled over for a 10 minute stop ,started car up and it idle at 400rpm and after 2 minutes the idle circuit started working again and I had a smooth idle and the car would rev up when you pushed on the pedal. I was able to make it back home doing 75-80mph getting 23.6 mpg. Very confusing ?????

[lefoy84]

Originally Posted by juanway

Drove vette from Denver to Taos, engine ran great, next day engine would start but run for 2 seconds, I found fuel filter plugged and pressure pop off connector just above fuel pump had moved enough to keep fuel from giving me full pressure going to F.I. Installed new fuel filter & pump and put a 1/4 inch submersible fuel hose with clamps where the pop off connector was. Engine would not idle until I closed the TB by backing off on the idle screw. so I let it run at 400rpm until it warmed up and the idle circuit kicked in and it idled smoothly at 600 rpm in drive. The throttle body was cleaned and a new IAC and TPS was installed pryer to going on trip is it possible the IAC or TPS may be Faulty and how do I check for proper setting of Both??? which one should be set first? No check engine light came on. I drove back to Denver Pulled over for a 10 minute stop ,started car up and it idle at 400rpm and after 2 minutes the idle circuit started working again and I had a smooth idle and the car would rev up when you pushed on the pedal. I was able to make it back home doing 75-80mph getting 23.6 mpg. Very confusing ?????

The pop off you refer to is called a pulsator. They often fail and can be bypassed with no ill effects.
You say you had to close the TB. It should have been at the stop.

Here is the procedure to adjust the idle speed:


First step is to set the minimum idle speed. If nobody has messed with this on your car before, the set screw will be covered by a pressed-in plug. It's located on the driver's side of the TB. Remove this plug if it's there.
With the IAC connected and the ignition "OFF," stick the paper clip into the diagnostic connector from "A" to "B." This grounds the diagnostic lead.
Turn the ignition to the "ON" position without starting the engine. Wait 30 seconds.
Now, with the ignition still in the "ON" position, disconnect the IAC connector at the IAC.
Remove the paper clip from the diagnostic connector.
Start the engine and allow it to reach normal operating temperature. The idle speed will probably be really low, and you may have to coax the engine a bit with the gas pedal to keep it running for a while.
If your car is an automatic, set the parking brake and put the transmission in "DRIVE." If your car is a manual, leave it in neutral.
Adjust the idle speed screw to obtain 400 rpm in drive or 450 in neutral.
Shut off the engine and re-connect the IAC.
That's it for idle speed.