Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
tell me what all you have done.....does the engine light come on?if so,can you give me the codes?
I have new injectors...new valve cover seals...new ideal air contro..speed sensor...temp sensors..o2 sensor...wires...plugs....rotor and cap.....all codes have cleared and none show up....just wont ideal after warm up and wont take off with out burping...i have a new fuel filter and have check fuel pressure..steady at 12/13 psi
have checked timing also.( one guy here suggested distributor or addvanced timing may be sticking)..this is my first attempt to work on a car so I dont know much!!
first remove and clean the egr valve,sometimes there will be carbon under the valve ,causeing a vacuum leak from the exhaust,,,also the egr solinoid [this is what the vacuum line from the egr valve connects to]will go bad sometimes and send a vacuum to the egr valve opening it when it dont need to.....you may also want to remove the iac valve and clean it or mabe replacve it sense it has sit for a while it may be sticking
please ACCEPT my answer so I can get credit for my work.i don't receive commission unless you do ..i'm not always going to be giving you good news,so please dont let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate.. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.PLEASE ASK IF YOU NEED MORE HELP
The ECMcontrols idle rpm with the IAC valve. To increase idle rpm, the ECM moves the IAC valve away from it's seat, allowing more air to pass by the throttle plate. To decrease rpm, it moves the IAC valve toward it's seat, reducing air flow by the throttle plate. A "Scan" tool will read the ECM commands to the IAC valve in counts. The higher the counts, the more air allowed (higher idle). The lower the counts, the less air allowed (lower idle).
IAC VALVE RESET PROCEDURE
A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range IAC "Scan" tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem.
Check for high fuel pressure, leaking or sticking injector. Silicone contaminated O2 sensors "Scan" voltage will be slow to respond.
i will opt out and see if any of our other guys may know what is going on.....please list all you have done
the only thing that is not new on the truck is the distributer and the ignition moduel
Fig. Fig. 2: Using a DVOM, backprobe terminals A and B of the TPS sensor to check for proper reference voltage
Fig. Fig. 3: Using the DVOM, backprobe terminals C and B of the TPS sensor, open and close the throttle and make sure the voltage changes smoothly
Fig. Fig. 4: Throttle Position Sensor (TPS) wiring diagram
i have changed this sensor 2 times once with a after market then went back with ac delco....is there a way to up the ideal manualy?
ok.. thanks. I dont have a ton of test equipment so I went with the put all new parts on and then see what wasnt working...now I am stuck. Cant get this one thing to work right. Stumble on takeoff and the shutting off at idel.
no ..we had a few codes early on but now with all the new parts on the codes have gone away. the check gauges light comes on when it starts to die at idel because the oil pressure gauge drops also.
i spent 6 hours today changing distributer and still no change....the coil is the only thing left to change. Today when I start the car it runs great..then when i drive it stumbles the goes. after it warms up it wont ideal. Seems like the idel is low. That being said now that the ne distributer is on I need to set the timming but cant. When I unplug the timming by-pass the motor shuts off. Plug it in then it runs..but will stall and shut off after a few min.
need help on a 1999 Chevy K3500 pickup with a 7.4 L