Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[BlewitUp]

OK...  Here we go.

1991 Capri 5 speed.  93 motor.

Car idles like crap.  It bounces around from 750 rpms to 1000 rpms.  It is more noticable when the weather is colder.  It is yet more noticable when the lights and HVAC blower are on.

When changing a V-belt, It was noticed that the intake plumbing was loose.  Tightened that up.  I will be looking for vac leaks, cleaning the Idle Air Control Valve, and replacing the air filter.

Starting fluid is going to be a big time saver here!

I will post what I find with pictures.

[rcdraco]

Oddly enough, I had the same issue on my car; I disconnected the TPS and the car idles great.  But my prime problem was a drop in mid range power while cruising, not necessarily sure if disconnecting the TPS fixed the idle, or if limp mode compensated.  When is the last time the fuel filter was replaced, and if possible check your fuel pressure to make sure the pressure regulator is operating properly.

[BlewitUp]

I will look into that.  Honestly, I just noticed my radiator fans are stuck on... Guess the relays fail closed. Nice to know I won't over heat.

I think the alternator is on the way out.  With all the load, it is making the engine stumble.  I have lots to look at.

With all of that said, it should catch its self after the alt levels out and its not.

[Rocketman]

Stumbling sounds like more vacuum leaks. The VAF is very sensitive to *any* leaks. Also check your plugs & cap/rotor... I've never had an alternator cause a stumbling. Is your battery light coming on? That will illuminate any time the alt is failing to charge.

For the hunting idle, it could be vacuum related. I had issues when swapping throttlebodies in the past, a poorly adjusted dashpot was causing a hunting idle for me. It was holding the plate open just a little bit, rpm's would shoot up, suck the butterfly closed, rpm's come back down, cycle would repeat. (the dashpot is the circular bit on the left side of the throttlebody, little white piece that sticks down on the throttle cam)

For your fan running constanly - is the fan switch plugged in? it's the single blade sensor on the thermostat housing. The sensor may have failed too, but I doubt the relay has failed

[rcdraco]

I have a dumb question related to the fan question.  I removed my condenser fan, since the blade has sheared off the motor.  Is the condenser fan used as an Auxiliary unit, or only when the A/C is on?

[Rocketman]

Only when the AC is on.

[BlewitUp]

Haven't done much about this, but I used propane to look for vac leaks and nothing turned up.  Pretty lame.  Guess I'm back to checking air/fuel filters, IAC and TPS.

We will see.

[BlewitUp]

Now my idle is stuck at 2000 RPM's...  What gives?  Anyone else have this issue?  I checked for vac leaks last time and found nothing.  Also, since the days are longer and warmer, I haven't been using the lights and heat (blower motor) so my low idle issues is "fine" at the moment.

Any pointers, or suggestions to check would be great.  I have finals in a couple of weeks.  It would be nice to actually spend some time on this thing at get it where it needs to be this summer.

[Rocketman]

make sure the throttle is closing all the way, not hitting on the dashpot or stop screw, if those are loose and worked themselves out from vibration it can cause a high idle. Not likely but possible.

For the time being, turn your idle down with the idle setscrew on the throttlebody. Keep a screwdriver in the car to adjust as needed where needed

[BlewitUp]

Hmmm.  I still have the screw driver in there to control my heat.      I can probably use that...  

Thanks for the tip.  I will check it out.  When I FINALLY HAVE TIME, I will report back on these issues.

[JJ]

if you have ac, i've seen a faulty ac switch cause high idle... or it was pushed in even though they system doesn't work or turn on... car tries to anticipate the larger power draw by increasing idle speed.