MG993

I have had it!! I no longer can deal with the check engine light. After replacing the plugs, wires dist. cap and several expensive trips to the dealer (Ogner) the light came on again after 2 miles. Each time OBDII code is a misfire. The dealer said it is carbon build up and just drive the car "hard" with more fuel additive. I need a shop that can fix the problem. Any suggestions? By the way the car has only 18K miles.

Kevin

Have they checked the 4 O2 sensors? How many miles are on the car?

SundayDriver

There are two things that I know of that can cause this problem and may be hard to find. A weak battery and a bad DME relay. If you do not want to mess with this, I can recommend Mike Schatz at Rusnak in Westlake Village.

Curtis - '97 Targa

MG993 -
I'm in the same boat. About every 100 miles or so I get a Check Engine Light. The code indicates a misfire on either 2,3 or 6 in some combination. I've done all of the things you've done: caps, rotors, plugs and wires to no avail. I even replaced the DME relay with the newer model on the off chance that would help.

I've heard about the "carbon build-up" thing as well as an expensive dismantling and cleaning of the intake ports that MAY solve the problem.

Because the car is running so good, I just reset the light with the PC software and drive on. I believe I'll just live with it but it is irritating. Most of the mechanics that I've spoken with run out of steam after doing the things we've already done.

After doing all of the things that we've done the OBD manual calls for the following steps:
1) Check Fuel Pressure;
2) Check triggering of fuel injectors;
3) Check for air leaks in intake air system;

There's a procedure for each in the manual.

Please let me know if you make any progress...

becker - 97'C4S

What was the code? I also had the check-engine light and I'm about to buy myself the OBD2 scanner tool
the carbon build up is common and happens when the car is not reved vigorously, that it's taken care by an Italian tune-up and some Chevron cleaner.

Look at the archives the issue come up already

MG993

Thanks for your prompt replies.

I just made an appointment at Rusnak, but that is not until November 15th.

I am going to see about running some tests this weekend. (ie. battery etc.)

As far a the code # I am not sure. The OBD2 is showing that the car is missing and the spark number seems to change just like Curtis.

I have never used an aftermarket OBD2 scanner are they easy to understand? Which one would you recommend? or is it easier to drive the car of a cliff? Just my fustration showing.

becker - 97'C4S

MG993 take it easy ... try the basics first that carbon-cleaning could be a major job I hear, from some flushing to opening up the engine, I'd leave that for when everything else fails. Your car has low mileage.

The OBD2 tool will allow you to read the codes,reset it, and log the codes, I've seen the one recommened by p-car.com and downloaded the GUI looks pretty good just trying to find out if there's another one out there.

If otherwise the car runs fine keep an eye on it and try the basics before doing something drastic.

Cheers

cecil

the light has a bulb ya know

MG993

Cecil, that would be a great idea to disconnect the bulb, but in California we have bi-annual smog checks (along with bad gasoline) and the light must be working to pass.

red targa

I bought a '96 Targa which had the same problem about a month ago. Had the Check engine light reset a couple of times, pour a bottle of Technron before filled up the gas. Still the light came on, had the car checked the second time, the service guy told me it is the airflow regulator (maybe he meant the air intake)requires replacement. He wants to charge me about US$ 700 for this job.

I live in Taiwan, and the service charges is very expensive, and the level of expertise is usually not so high.

John

Martin S.

One response posted was, "I can recommend Mike Schatz at Rusnak in Westlake Village." I second the motion. If you are doewn in Orange County, Kevin at ANDIAL has lots of electronic savvy. So far in nearly 15,000 miles, the check engine pight has not come on.

My new regimen is to use only Chevron gas, adding a bottle of Techron every 3rd fill up, and continue to drive the pants of the car at the track.

MG993

That is encouraging news. Like I said I made an appointment with Rusnak and Mike on November 15th. I will post the results.

DoubleNutz

My battery has been rather weak during start-ups. I am going to change it and see of the light goes away.

cecil

MG... Here is your problem. Your dealer is right it is carbon build up. The 993 has a port that adds air when you 1st start the car to offset it running rich. Thus the term "smog pump" This air port gets clogged with carbon. The dealer fix is to pull the heads and clean the carbon out. Expensive. I would not pull the heads on my car unless I had to. I'm not sure what the Ca. emissions test consist of but the car will probably pass any test when warm. The problem occurs when the car is cold. You may want to talk to a knowledgeable after-market guy about this. You may be able to pull the bulb and just put it back for the test clearing it 1st. In the mean time a tank with 2 bottles of Techron every 3,000 miles and a lot of full hot hard running may help.

Hoos 993

I had my mechanic do a BG Air Induction service this weekend. What a world of difference?! The engines responds (rev) quicker, idles about 150 rpms lower, and really smooth while driving. This service cleans out the build up around the intake valves and fuel injectors, and is industrial strength (forget about using Techron...).