Bad bad Idle

[SHOleen]

I have a 1993 ATX with a C&L mass air cold air and exhaust well this thing idles like crap i had a new Idle air control solonied put on and it still does it (by the way my dad owns his own shop the mechanic there is normally a geniose he just doesn't like touching a yamaha) , then i popped my hood and notice the maf was unhooked it fixed it for a couple days and then it started again i checked the connection it was good please help with any ideas

 

[Mr Anonymous]

Did you check for codes and reset the idle speed program? Either or both may solve the problem for you.

 

[rendyx]

Have you reset your idle? That will solve a lot of idle problems, among others. Basically, yank the negative battery terminal, turn on the headlights (this drains out more electricity), wait 15 minutes, turn the lights off, reconnect the negative terminal, start the car, wait 30 seconds for the idle to slow, turn on A/C, high beams, put car in drive (is it drive?), turn wheel left and right, and press brake pedal until the car has been running for 70 seconds. Then go out and drive, wait for the car to get up to normal temperature, and then do a couple WOT runs.

 

[SHOleen]

I did that idle reset procedure and it still does it once and a while not as noticeable but its still there the only code i could get out of my car was the iac (Idle Air Control Motor) which i then replaced, Could the mass air cause the problem running to lean, cause after i put it on i think the power below four thousand just suffers like there are only 4 or 5 cylinders

 

[SHOYourYama]

SHOLeen,
Did you order your maf w/ the mustang #19 sampler, or the SHO sampler?

 

[sdpatt]

Whether equipped with the original 24 lb/hr sample tube or the 19 lb/hr tube, the 73 mm MAF should not cause a bad idle condition. It sure never caused a problem in my car.

You haven't exactly described your idle problem with any descriptive terms. "Idles like crap" and "still does it" does not give us much to analyze. While the poor idle condition is happening, unplug the MAF. Does it change the idle? If so, you have a problem with the MAF. If not, we need more input. Help us help you.

 

[SHOleen]

Okay best way to describe it Shakes the whole car, forwared and backward the motor seems like it is way off balance but if i give gas it goes away but it doesn't do it all the time. Also i tried disconnecting the mass air and then reconnecting it the idle never changed.

 

[Dr.Evil]

I have a simmilar problem, but it only does it from time to time. Ok, so I drive somewhere and the engine gets up to operating temp. then I stop and when i come back to leave 20-30 mins later is when it happens. It will start, but will not idle. it sputters, jumps from like 200 rpms to 700, with the OIL light flickering on and off. I just pump the gas and it doesn't do anything. it does this for about 30 seconds, then I ask it nicley and it will go away in less than a minute and not return. Weird thing is that it only does it occasionally. I dont get it. I have changed the TPS, cleaned the MAF, and replaced one of the O2 sensors (didn't realize it has 2). I noticed that the intake has some rub marks from the underhood liner indication failing motor mounts. But besides thoes things what could it be?

 

[sdpatt]

During the hot restart conditions that cause the most problems, when you turn the ignition key to ON, do you hear a low rumbling sound from the fuel tank area?

Also, you can try to turn the key to ON a couple of times for about 2 seconds each to cycle the fuel pump and pressurize the fuel rails before trying to start the engine.

If either of these methods changes the starting behavior of the engine, you have fuel pressure issues. The first is a symptom of leaking fuel return line check valve. The second is a symptom of a leaking fuel pump check valve in teh fuel pump. Both replacements require dropping the tank and removing the pump assembly.