Hi all-

I recently removed the AIR system, cats, and A/C on my 87 TPI formula while installing headers. Afterwards, the car's idle quickly degraded and the car started dying alot. Also, it smelled like it was running quite rich, and my cooling fan is on all the time.

Previous to the modifications it had a slightly poor idle, which seemed to get amplified afterwards. It then started throwing the egr code on the highway; so I replaced the egr valve.

Now it idles HORRIBLE and has zero throttle response right after start up. However, after driving around for a bit and once the temps hit about 150 it runs and idles fine.

So I guess I have two main questions here:

(1) How do i get my cooling fan working properly again?
(2) Why does my car run like a$$ on start-up?

Please send help soon!

Thanks

 

Germ,

Man, talk about bad luck - you found it.

I'm not sure about the cooling fan without a little more detail, but I may be able to explain the poor cold starts. The oxygen sensor needs to reach about 1600°F to send reliable signals to the ECM. The A.I.R. system diverts extra air to the exhaust manifolds on cold starts to help complete combustion, thus heating the cat and sensor faster. This may explain the rich operation aftercold starts, but not necessarily the poor performance.

Since you started experiencing the problems right after the change, you might want to double check the connector at the AIR diverter valve to make sure it isn't grounded.

 

Perhaps the problem has nothing to do with your recent header install and AIR removal. The fact that your fan is running constantly suggests that possibly your CTS is bad. If your CTS were giving the computer a temp reading of around 220*, your fan would run constantly, and the car would idle really rough until the car actually reached 220* or so.
It would be really coincidental for your CTS to kick the bucket at the same time you did some work on the car, but dont rule it out as a possibility. If you have a scanner to hook it up to, that would provide some good information.

 

When I did my header install I destroyed my CTS case when I took out the old manifold. My problem was that the fan would not turn on and the car would over heat, hence the manual fan switch.

So my thought is that it may be the sensor that controls the fans for the AC. It may think the AC is always on pressure > 44KPa?

 

when i removed my a/c my fans ran straight from start up,then i
plugged the lead that goes into the a/c pipe back in and the
fans worked properly again, then i unplugged the lead and
put part of a paper clip accross the two out lets of the lead and
that also made the fans work normaly, so i could then remove the
last length of a/c pipe,i've been running it like this for twoish
months and all is ok.........so far.

 

I replaced the CTS shortly after the install, cause I too destroyed the connector with the passenger side header. Fans still ran.

Recently I jumped the plugs of a pressure sensor for the AC, but that didn't stop the fans either.

Any more thoughts?

Thanks guys-

 

Yeah, that's the a/c "high pressure switch" that ROB87GTA's talking about. When the a/c system reaches a very high pressure, this switch opens and turns the fans on. So by disconnecting this two-wire connector, you simulated the switch "opening". Just stick a piece of wire in the connector, between the two terminals. This is the connector that went to the a/c hard line on the passenger side main frame rail.

Same thing happened with me when I removed my a/c ... good spot for a fan switch, eh?

 

So beyond the cooling fan issues...

Could a heated O2 sensor help solve my crappy start up conditions? If the computer's running closed loop then, and the 02 sensor isn't heating up as fast because I removed the AIR system....it could cause these problems, right?