engine stutter and running rich

[newowner1]

Thanks for all the help the forums have given me. I am having a problem with my truck. Its a 1987 2wd 350tbi. I just did a complete tune up. except for fuel filter. the truck has a dead spot particularly when i put it in reverse after starting when cold. but it has the dead spot even after it gets warm. it happens most when you just barely pput pressure on the gas pedal. The injectors are crazy loud and they are dumping a ton of fuel in there. You can really smell it out the exhaust and my gas milage is terrible. any direction?? Thanks everyone.Already tried the cts sensor by the thermostat.

[roundedline]

Are you getting any codes from the ECM?  Vacuum leaks?
By dead spots are you talking about it being non responsive for a period and then picking up?

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[VileZambonie]

I would say check the TPS and Check the Map sensor. And by cecking I don't mean just replace them.

[newowner1]

Yes, I mean an unresponsive spot in the pedal but it doesnt pick back up. If I laeave my foot there it will either barley idol or completely die. What are the steps I need to go through to check the sensors. No, I am not getting and CELs or anything.I also tried the WD-40 trick and there is no change in rpm anywhere I spray it.

[VileZambonie]

You need a few tools. One would be a digital voltmeter. If you have access to one I'll tell you how to test each sensor to see if they are giving you your problems.

[newowner1]

Yeah, I have a voltmeter. Thanks a ton for the info.

[newowner1]

Could you post the info I need for testing those sensors?
Thanks.

[newowner1]

Does anyone have the info for testing these, or maybe point me in the right direction. Thanks

[roundedline]

MAP:
Test the MAP sensor output voltage at the MAP sensor connector terminal B. With the ignition switch ON, and the engine OFF. Output voltage should be 4 to 5 volts.

Test the MAP sensor output voltage at the MAP sensor connector terminal B at a hot, neutral idle speed condition. The voltage should drop to 1.5 to 2.1 volts.

Test MAP sensor supply voltage at sensor connector terminal C with the ignition ON. The voltage should be approximately 5 volts (ħO.5 V).


TPS:
engine/ingnition off:  put an ohmmeter on the middle and either top or bottom terminal and slowly move the throttle.  It should move smoothly.  Take note the readings.
Swith to the other outer terminal and test again.

If the readings are erratic/infinite you have a bad sensor

At closed throttle (0%) it should measure about .45 volts. At wide-open throttle (WOT - 100%) it should measure about 4.7 volts.  It should at least be less than 1.25 volts with throttle closed.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project