Hi everyone,
New here, I'm having an issue with my Blazer not wanting to restart after it gets hot from driving. I would have to press the gas pedal to get it going, other wise it would try to start and just die. onced started it seems like it idles a lilttle lower than normal. I have replaced the fuel pump last May due to the gas gauge not working and not sure when the last time it was replaced with an OEM AC Delco from RockAuto. Also have changed the pvc valve and cleaned the throtle body. Also Im not getting any CEL's. This happens about once every other week. other than the occassional starting issue it runs great no missfires or anything. Any help or suggestions would be great. I have searched the other threads but havent really found any issues the same as mine. A lilltle info on the Blazer it's a 2003 2wd auto with 190k miles on it.
Thanks

 

Low fuel pressure can have symptoms like you describe without illuminating the SES light and setting DTC's. Check fuel pressure and leakdown first. Key ON, engine OFF, fuel pump running, pressure must be 60psi to 66psi and must remain above 55psi for 10 minutes after the pump shuts off. With the problem being intermittent, you might need to check it when it's acting up.

 

Thanks for the reply, ill get the pressure tested and post the results.

 

did you check iac valve... holding the throttle open feed it air that maybe restricted cause the iac might not be fully open... heard of it before....

 

Get your IAC tested. Ignition control module. Make sure they test it several times in a row so it gets hot. When the IAC fails, it fails whiel hot, once cool it operates like normal.

Also check your TPS, I didnt read all your info, so you may have two of them, one for idling and the other for normal operation.

 

Thanks for the tips. Havnt had a chance to vet the fuel pressure tester yet but will post when I do. As far as the module testing goes were can I have that tested autozone or advanced? Also if its failing would it still allow it to start with the gas pressed?

 

Remember the test that counts is key on-Engine off, then time pressure takes to drop below 50 psi. We dont care -yet- what the running pressure is.

Here's how to test the IAC for movement. I just did this test yesterday, my truck has no operating problems and results showed the IAC would open and close to adjust rpm, so it should work.

Engine warmed, disconnect the MAF connector and remove the intake tube from the throttle body.
Open the throttle with your hand on the throttle crank. Spray the throttle plate and bore with intake cleaner. Wipe down as accessible.
Start engine. If necessary use something the thickness of business card on the throttle stop screw.
Looking down into the barrel, above the throttle plate, you will see the IAC intake slot.
Plug it with your fingertips, the PCM should try to open the IAC to compensate. If it dies, start it again and spray intake cleaner, in short bursts, into the iac slot. Use fingers again to partially plug slot. repeat several times.

If not successful with intake cleaner use a short shot of PB Blaster and repeat several times.
Worst case.. you have to replace the IAC.