Check Engine Light

[Q45_1992]

For the past 3 weeks my 92 Q has the check engine light coming on. It has 185,000 miles. At the same time it idles rough; like 7 of 8 cylinders are hitting. The light comes on only after the car is re-started hot after sitting. Once I drove it long enough (30 miles) where the light went on for the first 5 miles, off for about 5 and then back on for the last 10 -15 miles. So I get it to my independent mechanic and the light never stays on long enough for his computer ( a small hand held model) to anaylize the problem. At first it read a fuel injector was malfunctioning but never had it running bad long enough to see which one. Then he said it could be the car's computer. He told me to get some Chevron Injector cleaner in the tank when it gets down to 1/4 (not there yet) to see if that will work.Questions: Any ideas on what this problem is? Any suggestion on how to analyze this?

This is driving me nuts.

Thanks in advance.

Regards, Doug Evans

[maxnix]

Doug, welcome to the board. It might help if you can detail the maintenance you have performed the last 100K miles or 3 or four years to parse the problem down.

Having a dealer use a consult might be your best bet.

[DAEDALUS]

Welcome! All right, another SoCal member! 450 more and we'll have as many members as Kentucky. Use the red search button at the top to find answers to many of your future questions. There is a way to retrieve the codes by yourself, and it takes maybe 1/2 hour. Regardless of whether the light goes off, the error code is stored in the ECU for 50 starts, so your mechanic has no excuse for not getting the code.If you want to keep the car for a while, then perform the following searches: "chain guide", "error code ECU", "MAF connector idle". I think a loose MAF connector might be your problem, but the other searches will turn up valuable knowledge.Also, save your money on the injector cleaner, and pick up some BG44k. How long have you had the car?

[Q451990]

If you've never had a pressurized injector/rail flush - that's your first step! Also, try wiggling the MAF connector around - if you notice idle changes you may have found your problem. Since you're getting the CEL I'd think it's more likely a bad sensor. The CA emissions ECU has more things that it checks so it may show an injector fault, but Federal ECUs, at least the early ones don't.

Heath

[Q45_1992]

thank you all for the input.

I don't have the space nor the time to work on it myself.

Do you think I can show your suggestions to my mechanic or should I (dare say!!) go to the dealer!!

My Mechanic's great but a little low tech.

Thanks again,

Doug

[DAEDALUS]

Where in RB are you? I'm practically down the street from you. I haven't had very good luck with the local dealers. Someone posted Cerritos is great, but I haven't been out that way.

[PalmerWMD]

You can always tell which injector is bad even if it isnt runing.your tech can ohm (chekc resistance) on your injectors, to see which, if any, are bad.

Also as for the check engine light, I am also leaning towards a sensor.(even tho rough running is also considered typical for an injector).

Fred...

[cdiver]

what is the spec resistance for a 94Q injector?

Thanks,

Stephen

[Q451990]

Check this link out... it'll answer all of your questions about the ohm test! Q45Tech has mentioned that you should do two ohm tests... one with cold injectors and one just after driving for a while. Sometimes they crap out under a hot soak condition.

Just remember it's possible to have injector related problems without a bad ohm reading. e.g. Leaking o-rings causing a rich cylinder, dirty injector causing poor performance, cracked tip near pintile... etc.

Heath

[mortimer9]

Daedalus What is BG44K? Where do you get it?

[DAEDALUS]

http://www.ec-securehost.com/R....html

Short description of product here, and you can also get it from Scottsdale http://www.infinitipartsusa.com for the same price. Include it with your next parts order to save on shipping.