Opinions. Stalling out - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bojak · 08-16-2014, 10:18 PM

Was hoping to get some opinions on an issue my truck is having. Cranks good, runs great. That is until you get some where that requires a lot of idling, like pickin up kids at school waiting in the mom line. It will die out and almost not restart. Have to heavy gas it to get it regoing, to my sons embarrassment. Acts like it's starving for fuel. Here is the list of what has been done so far.
New fuel tank
New sending unit
New filter
New plugs n wires
New cap and button
New starter, battery,alternator, new cables for battery
Headers
Exhaust
New o2 sensor
New air filter with salad bowl
Tbi spacer
The truck is a 5.7 TBI and I just did the tank and sending unit this week but that doesn't seem to have fixed it. I didn't necessarily do the tank and unit to correct this problem but had hoped it would. Also my fuel gauge is not reading now after installing the new tank unit and switch. Still reads passenger side but flip to the drivers side where all the new stuff is and nada. Any suggestions?

cadillac_al · 08-17-2014, 11:26 AM

I never had to touch a GM TBI because they are so reliable, so I don't know what kind of idle control it has, but it sounds like it isn't working right. If it has normal engine power when it is running, then it must be getting fuel. Fuel pressure should be verified anyway.

pontgta · 08-17-2014, 11:40 AM

Give this a try

Posted RFmaster orginally:

http://67-72chevytrucks.com/vboard/s...d.php?t=515419

1. Install a jumper wire between Pins A & B of ALDL diagnostic connector.
2. Turn on the ignition (but don't start the engine)
3. Wait 30 seconds.
4. Leave ignition on and disconnect the IAC connector (four wire plug).
5. Remove the jumper wire from the ALDL connector.
6. Start the Engine. The engine probably will run rough and may stall. Just restart and try again.
7. Adjust the throttle stop screw to set the idle to 500 RPM +/- 50 RPM. - stock camshaft!
8. Turn the engine off and reconnect the IAC connector.
9. Turn ignition on and adjust TPS to proper settings. (0.60 - 0.65Vdc at idle is typical, but 0.3 to 0.9Vdc will work)
10. Repeat procedure until the 500 RPM +/- 50 RPM (stock cam) in step 7 can be maintained while TPS is at proper idle setting. Performance camshaft may require higher idle RPM!

bojak · 08-17-2014, 09:09 PM

Good info and thanks. This kind of real feedback is what makes this site so valuable.

08-16-2014, 10:18 PM	#1
bojak Registered User Join Date: Oct 2012 Location: atlanta, GA Posts: 222	Opinions. Stalling out Was hoping to get some opinions on an issue my truck is having. Cranks good, runs great. That is until you get some where that requires a lot of idling, like pickin up kids at school waiting in the mom line. It will die out and almost not restart. Have to heavy gas it to get it regoing, to my sons embarrassment. Acts like it's starving for fuel. Here is the list of what has been done so far. New fuel tank New sending unit New filter New plugs n wires New cap and button New starter, battery,alternator, new cables for battery Headers Exhaust New o2 sensor New air filter with salad bowl Tbi spacer The truck is a 5.7 TBI and I just did the tank and sending unit this week but that doesn't seem to have fixed it. I didn't necessarily do the tank and unit to correct this problem but had hoped it would. Also my fuel gauge is not reading now after installing the new tank unit and switch. Still reads passenger side but flip to the drivers side where all the new stuff is and nada. Any suggestions?

08-17-2014, 11:26 AM	#2
cadillac_al Registered User Join Date: Oct 2013 Location: Maine Posts: 2,355	Re: Opinions. Stalling out I never had to touch a GM TBI because they are so reliable, so I don't know what kind of idle control it has, but it sounds like it isn't working right. If it has normal engine power when it is running, then it must be getting fuel. Fuel pressure should be verified anyway. __________________ 76 Chevy K20 76 GMC K15 77 Chevy C10 77 Chevy K10

08-17-2014, 11:40 AM	#3
pontgta Registered User Join Date: Nov 2009 Location: Haines City FL Posts: 461	Re: Opinions. Stalling out Give this a try Posted RFmaster orginally: http://67-72chevytrucks.com/vboard/s...d.php?t=515419 1. Install a jumper wire between Pins A & B of ALDL diagnostic connector. 2. Turn on the ignition (but don't start the engine) 3. Wait 30 seconds. 4. Leave ignition on and disconnect the IAC connector (four wire plug). 5. Remove the jumper wire from the ALDL connector. 6. Start the Engine. The engine probably will run rough and may stall. Just restart and try again. 7. Adjust the throttle stop screw to set the idle to 500 RPM +/- 50 RPM. - stock camshaft! 8. Turn the engine off and reconnect the IAC connector. 9. Turn ignition on and adjust TPS to proper settings. (0.60 - 0.65Vdc at idle is typical, but 0.3 to 0.9Vdc will work) 10. Repeat procedure until the 500 RPM +/- 50 RPM (stock cam) in step 7 can be maintained while TPS is at proper idle setting. Performance camshaft may require higher idle RPM!

08-17-2014, 09:09 PM	#4
bojak Registered User Join Date: Oct 2012 Location: atlanta, GA Posts: 222	Re: Opinions. Stalling out Good info and thanks. This kind of real feedback is what makes this site so valuable.



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