Hey guys I have an 88 IROC 350 TPI. So I'm driving down the highway doing about 80 - 85 my normal speed. According to the gauges my temps low, oil pressure is high, and the alternator output is high as well. Then all of a sudden the light comes on, no changes in any of the gauges. I dont have too much history on the car as I just bought it. Its got 111,000 on it and it runs real strong from what I've seen. However I did notice that the sensor on the plastic housing before the throttle body is disconnected. It had been since I bought the car but the light never came on, maybe the computer just noticed? I cant find the disconnected cable maybe its tucked away somewhere? Any Ideas? Somoene mentioned the 02 sensor I'm gonna check it out. Let me know any ideas please.. Thanks in advance..

-Tom

 

My guess is it is the egr, it is a fairly common problem. TH egr doesn't work properly at sustained crusing speed. Happened in my '89 everytime I drove on I-95 for the 2 years before I just pulled the egr all together. You aren't hurting anything if it is the egr. You should run a code cheack on your engine. Take a paper clip and jump the upper right hand two plugs on your Aldl (The little port, below and to the right of your steering colum) Turn the key to run but don't start the car. The SES light should flash out your codes in a kind of morse code fashion. You will get a code 12 first, 3 times in a row, and then what ever other codes you got. As for the unpluged sensor, the one right before the throttle body would be the mass air flow, and if thats unpluged the car would be runnging like crap and you would get a SES light right away, unless the previous owner converted to speed density. Hope this helps. Welcome to the site

 

Ahh.. Sorry but what is the EGR? Where is it located and such? Also where abouts would the wire be that plugs into the mass air flow sensor because I can't find the wire. Thanks in advance

-Tom

 

DrekkenX-

Yeah, it sure sounds like an EGR problem to me and I'm going to warn you now, it can be a real hassle to get fixed... but here we go...

The EGR system is an exhaust recirculation device that heats your cars engine by channeling exhaust gas back through the engine. It is located directly beneath the plenum, to access it, you'll need to remove the plenum and runners on your TPI unit.

The problem can be 1 of 3 things:

1: The lines connected to the EGR have a vaccum leak, which is causing the code to signal and may also be causing loss of performance. To check for this, check each wire and make sure they are tightly on. If that check out, then apply a small coat of soap and water mixture onto the plugs... start that car, and look for bubbles (this will signal the location of the leak). Replace the wires as needed.

2. The EGR solenoid (the switch that opens and closes the valve) is not functioning and needs replacement. You'll probably have to have a mechanic shop or dealer install a new one.

3. The EGR valve itself is shot and needs replacement. Again, have a mechanic shop or dealer take care of it.

The EGR system is really cheap, so don't worry about pricey parts. The only thing that may cost you is labor, because getting the plenum and runners off takes some time.

Good luck

-ONE2FLY

 

Er.. last time I checked that EGR valve is pretty expensive.. and labor for replacing it is almost non existant, you can easily do it in less than 20 minutes if you have a pair of arms. Don't pay someone to replace it.

ONE2FLY - Just cuz some guy on the internet says to take your car to the dealer doesn't mean that you should :P replacing the EGR valve is very simple in our cars, so don't go handing your car over to someone else to fix unless you've got big problems.

 

Oh boy Well when I got home and turned off the car i never saw the check eng light again, even driving on the highway back home but i stayed around 75 - 80? Still and EGR? Maybe I fluke? I'll check it out all the same. Let me know what you think!

thanks

-Tom

 

I would dearly love to see someone change the egr valve on a TPI car in twenty minutes. That would be a neat trick.

Also, lets not forget the egr diagnostic switch. (this is just a little feller that screws into the base of the egr valve) I found that mine had "broken loose" inside the housing, so the switch was always grounded. (the computer reads that as egr enabled, and at idle, on a cold engine, that is just not supposed to be....) After replacing the switch, the light went off and stayed off.

I drive from my home to Cleveland on a fairly regular basis, some 160 miles one way, and I do not have any further problems with the egr system. ( I would really like to invoke highway mode in the prom though...........)