Idle Speed

[herrmann66]

[b]I have a 1990 Geo Tacker 5 speed and I just replaced the fuel injector and the computer and I now have an idle speed problem, as well as my accelerator sticking. When I come to a stop my idle drops and rises uncontrollably. I have taken it to 2 shops and they can't seems to figure out what is wrong. My check engine light is on and once again I had a diagnostics test done and they can't pull any codes. I'm stuck!

[netlos]

sounds like a problem i had on my 89' gmc tracker years ago.check to see if your distributer is loose,and if your accelerator cable is sticking.take a look at your plugs, coil,and wiring.if all is good and your computer and injector are not malfuntioning it may be your valves(hope not),but if it was running fine before the injector\computer change chances are its not the valves.good luck.

[rallykick]

is it idling form 500-1000-500-1000 rpm if it it's a valve I can't remember the name almost every vehicle has one for some reason egr valve is coming to mind anybody else know for sure

[Shconer]

An EGR valve might be the problem, check for any disconnected vacume hoses. It might be the idle control valve located on the intake maifold it allows air to bypass the throtal body. But if it was idling fine before than this probably isn't the problem. What's was the reason for replacing the injector and the computer? If the engine light is on then there are codes.

[hossstyle]

I am having the same problem. Did you get yours fixed. HELP!!!!!!

[Ozzy77]

try by checking the egr valve when the engine is doing that, does it open or not? Just to be sure I had seen '90 engine and some of them have 1 wire O2 sensor is your 1 or 3 wires?

[hossstyle]

I have one wire.

[hossstyle]

It seems the fuel injector is pulsating and that is what makes the engine idle up and down. When I put my hand over the throttle body the engine idles below a 1000rpm and runs smooth. Have checked EGR, replace the oxygen sensor, replaced PCV, pulled map sensor vacuum hose and engine runs rich. Check all vacuum hoses and sprayed for vacuum leads, but to no avail. Have recently replaced new fuel pump, fuel filter and relay. And have just replaced the computer. I still am not able to pull codes and check engine light is still on.

[cheyenne'88]

hossstyle, do you have a 4 pin or 6 pin connector to check codes?

Maybe you guys have a "sticky" injector, or some flow problem. You should try some Marvel Mystery Oil or Z-Max in your tank. The latter worked great for putting a little zip back in an old vehicle I had. I think it needed a little lube to smooth it out. Either that or it helped get a blockage loose.

[hossstyle]

it is a 4 pin but only three wires.