My new SHO's first problem.

[337]

Hi, I bought my first ever SHO on monday, and am enjoying it immensly! Well I'm into my third day of owning her and just ran into a problem.

The problem started right after work when I started her cold. I let her warm up a bit and then started playing with the climate control to clear the fog on the windows. I then noticed that the idle was fluctuating about a few hundred rpm. I thought nothing of it at that time because I was playing with the A/C and didn't really know how it reacted yet.

I then drove for a little bit with no problems, went through a car wash later on. About 45 minutes after the car wash I came to a red light, put it in neutral and after a few seconds, the idle raised from around 900 rpm to about 1400 rpm and started jumping around a little bit before it would dip to around 500 rpm and stall out.

It seems that the car does it now everytime in neutral when at a stop. It accelerates fine, doesn't buck, miss, etc going through the gears. If I start out with just the clutch in first gear, it seems to run fine with a little bucking at 1000 rpm(without pressing the gas). Every manual I've owned did this, and it bucked a tad more in second, but nothing really bad.

Sorry about making this so long, I'm a bit worried about it and wanted to make this as clear as I could.

Any answers/leads are greatly welcome!

Lee

 

[337]

Also I should add that I'm pretty sure the thermostat failed in the open position too. It akes about 5 min of idling and a little bit of driving to get it to warm up to at least past the blue on the temp guage, then it finally goes half way up the temp guage. The thermostat gets replaced this weekend.

Lee

<small>[ June 12, 2002, 11:28 PM: Message edited by: 337 ]</small>

 

[AutoSHO]

337:
Also I should add that I'm pretty sure the thermostat failed in the open position too. It akes about 5 min of idling and a little bit of driving to get it to warm up to at least past the blue on the temp guage, then it finally goes half way up the temp guage.

Lee

As for the idle fluctuation - take your battery negative cable off tonight. Tomorrow morning, re-connect it and follow the procedure in your owners manual for re-setting the car's idle. After you do this, take it for a spin through its entire operational range <read: all throttle positions, including WOT>. If it continues to go up and down, follow the procedure on SHOtimes for cleaning the IAB. That will fix the problem almost assuredly, and you will have to reset the computer after you clean it. Good luck!

 

[337]

Thanks, I'm going to get started on it right away.

Lee

 

[Emerald94]

Since your changing your thermostat, you should also replace the temp. sending unit.

 

[Emerald94]

Is your SHO a SLO conversion by any chance?

 

[337]

Is your SHO a SLO conversion by any chance?

No, this one was born a SHO.

I took my codes this morning and I got a 172&176(oxygen sensor not switching, both banks, system is/was lean-fuel control) and a 542(Fuel pump open, bad ground or always on-power/ fuel pump cicuits).

Recently, my dad's ****** had a very similar problem that I traced to being the lower intake manifold gasket that was cracked and causing an air leak. The SHO exhibits all the same symptoms, minus all the backfiring. So i'm expecting something similar.

Either way, this gives me a chance to get in there, clean a few things and look around a bit...YAY!

One more question, I'm sure the car needs a 100k service, can I get away with using a stage 1 cam and the supplied new shims and avoid doing all the measuring,etc for the shims? Sorry if this question sounds ridiculous, but keep in mind that I have never done a 60/100k service and am not a 100% sure how to go about it yet.

Thanks,
Lee

 

[Markus]

AutoSHO:

337:
Also I should add that I'm pretty sure the thermostat failed in the open position too. It akes about 5 min of idling and a little bit of driving to get it to warm up to at least past the blue on the temp guage, then it finally goes half way up the temp guage.

Lee

As for the idle fluctuation - take your battery negative cable off tonight. Tomorrow morning, re-connect it and follow the procedure in your owners manual for re-setting the car's idle. After you do this, take it for a spin through its entire operational range <read: all throttle positions, including WOT>. If it continues to go up and down, follow the procedure on SHOtimes for cleaning the IAB. That will fix the problem almost assuredly, and you will have to reset the computer after you clean it. Good luck!

Bad O2 sensors can cause this too. Extract codes from the EEC and let us know what you find.

Mark

 

[Markus]

337:

Is your SHO a SLO conversion by any chance?

No, this one was born a SHO.

I took my codes this morning and I got a 172&176(oxygen sensor not switching, both banks, system is/was lean-fuel control) and a 542(Fuel pump open, bad ground or always on-power/ fuel pump cicuits).

Recently, my dad's ****** had a very similar problem that I traced to being the lower intake manifold gasket that was cracked and causing an air leak. The SHO exhibits all the same symptoms, minus all the backfiring. So i'm expecting something similar.

Either way, this gives me a chance to get in there, clean a few things and look around a bit...YAY!

One more question, I'm sure the car needs a 100k service, can I get away with using a stage 1 cam and the supplied new shims and avoid doing all the measuring,etc for the shims? Sorry if this question sounds ridiculous, but keep in mind that I have never done a 60/100k service and am not a 100% sure how to go about it yet.

Thanks,
Lee

I will all but guarantee that your idling problems will be cured by changing to O2 sensors. Error 542/543 always pops up when an O2 sensor is bad.

Mark

<small>[ June 13, 2002, 12:25 PM: Message edited by: Markus ]</small>