Service Engine Soon Light

Here's a stab at it, guys like Dr Fiero might know better.   I can only hedge on this based on some experience from my carburated car days and mid 70's pollution gadgets.

The starting at 2000 rpm and settling down at around 1300rpm when the engine is cold is normal.  The 1300 rpm is high idle and it is set to warm up the car faster to get the catylitic converter to operating temperature as quickly as possible.  When you start your car, the fuel pump comes on first to prime the injectors so when the car turns over, a dumps fuel into the cylinder so start up is slightly rich.  Once the car warms up, your idle should settle down to normal around 800rpm. 

Your idle dropping down to 500 rpm sounds troublesome because at 500 rpm, the engine should be very close to stalling.  It is possible that the fuel is not atomized enough and hence did not mix with air properly to combust.  If that is the case, your fuel injectors might need servicing.  (just a guess)

 

 

Well now that I have been trying to take a video of it starting bad, it starts fine, but the service engine soon light has come back. I also have not had time to look at the injectors yet. I did have them recently cleaned, but that was a few months ago and I wasn't having any problems then and this started recently. I no longer have access to a scan tool, but I think it may be the O2 sensor. Could that cause the rich exaust code?

Not that I know of. The exaust is original y-pipe and up. I don't smell any leaks or hear any. I only get the light after the car is warm and is sitting at a stop light for a while. It goes away after I start to drive or sometimes goes away by itself. Occasionally the light comes on when going up a long hill at 50km/h in third but, I've had the car for a little more than a year now and it has only done that twice. Once last year and last week. Thanks.

Without looking at it in person, I really can't help you much more...

I *can* tell you though, that with no cat on an '88 you will fail aircare on the visual inspection.

Thanks for the help I'll get my injectors looked at when I get some time off. As for the Air care I won't need to worry about that. Thank you.

Here is the page I used to diagnose my MAP sensor issues when my SES light was bothering me, read it over a few times and consider doing it.

http://www.fiero.nl/cgi-bin/main.cgi?ECMCodes

88FieroGT wrote: For the jumping of the pins, do I just use a paperclip or some kind of wire? Thanks for the help.

As long as the paperclip is uninsulated.

A simple chunk of wire stripped on both ends and then bent into a "U" is what I usually use in a pinch.

Or you can show up at a club meet and probably 'someone' will bring one of the several scan tools floating around amongst the members.

I just did the code check and it came out with code 35 IAC. I just replaced the IAC within the last couple months. When the code was set, the conditions were no different then with the old IAC. I was sitting at a light for a bit and it set the code. The car was warm and I had been driving it for a while. Now that the weather has cooled down, my car starts fine now. I read what it said on http://www.fiero.nl/cgi-bin/main.cgi?ECMCodes . I think my idle speed is too high when the code is set and it says to check for vaccum leaks. Which vaccum hoses am I looking for. Should I clean the old IAC and put it in to test or should I just deal with the new one in there? Thanks

Thanks I'll look soon.

None so far except that I found a crack in my EGR vac. line. I was going to go tomorrow to get some model airplane fuel line and some shrink tubing that my grandpa uses on his model airplanes. I heard somewhere that the fuel line works good to fix a leak but I don't remember where. I couldn't find anymore vac. leaks unfortunatly. Are the little rubber fittings that connect the vac lines to the egr, and other things, prone to causing leaks? Some that I found seem to have some hairline cracks but dont seem very deep. Thanks.