My 97 C230 developed a problem where it won't run properly until it warms up.
It starts fine but when I put it in gear it bogs down and is not driveable. If I tap on the accelerater when its in park it seems to want to almost cut out. Once it warms up it drives and runs fine.

I pulled some codes with a scanner and I got the infamous P0170 along with P0300, P0301, P0304, P0303, and P0302. I believe they are all misfire codes.

I know from reading some of the threads the 0170 sometimes indicates the AMM. Anyone have any ideas how I could narrow this down some. Does this year car still have the wiring harness problem.

Thanks for any insight.

Hopefully someone can tell you what all those other codes mean. But I have one question: How many miles on the car? It seems that everyone goes into denial about their AMM. Has yours ever been replaced? If not then it might be a likely candidate considering the age of your car. How often have you changed your air filter? This seems important for long AMM life. I never knew that. (learned from a recent thread). Try the "search forum" for more info. Maybe search for those codes.

Mike

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

The car has about 110,000 on it but i don't have a repair history. I was reading some of the threads but they usually reference hard starting and/or loss of gas mileage when the amm goes. My car starts, it just misses badly when its cold. As soon as it warms up it runs ok, although I seem to remember it being quicker and smoother prior to this problem.

Hi Vin,

Have you made any progress on this? Hopefully one of the resident experts will chime in with an opinion for you. I looked at my alldata info since our cars are similar and confirmed that all the 300 codes you getting are misfire as you said. Does anyone know how to determine if an AMM has been replaced? Is there a date code on it anywhere, since Vin doesn't know if his is original. There is a theory that problems are related to car color, what color is your car?? (this theory is a joke of course) Having said that, Blue and Black cars seem to have bad AMM's...

Mike

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Before doing anything, change the two plug to coil connectors/resistors under each coil..
common misfire part..without spending big $

Hi Mike
It must be something else then because the color of mine is gold lol. All kidding aside I've done a lot of reading in the archives and the problem is that the answers and opinions vary so dramatically that its hard to formulate a logical conclusion. I'd hate to just start throwing parts at it but I think thats going to be the road I take.

I've been trying to find a reasonably price diagnostics tool. I bought an Innova code reader but it only gives you the codes and lets you clear them. I've looked at the Ease scanner but I don't know if that will give me much more information. I'll keep hunting around a bit.

Thanks for your help

Vincent

There are some O2 readings or something you can download with a scan tool that can help diagnose the AMM. I think there was a thread a week or 2 ago that mentioned that. I suppose you could pay someone to diagnose it for sure. Changing the AMM is simple and I don't think changing the plug wires is too hard although I have not done it myself yet. I think that is what Arthur Dalton was talking about.

Mike

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Check out the thread of 9-26-04 "Check Engine Light on C230" See if that is any help.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Thank you both
In the meanwhile i i tried to clean the amm up a little bit. I disonnected the battery to reset everything and now it starts and cuts off right away so its not running. I ordered a new amm. I will probably replace the coils and whatever else might cause a problem. I would go for more diagnostics but reading some of the posts has convinced me that it would be cheaper to replace the parts one by one making the best guesses possible. I looked at the wiring harness and it doesn't appear that its in bad shape. I tried to find the ovp relay but its in a different spot than it is on my 95 c280. I'm pretty sure its the relay in the trunk in front of the battery next to the radio fuse box. Anyhow I will keep you posted on the outcome.

Vincent

Ok
I just put in a new AMM and she runs just like new. Thank you all for your help and thank all the posters for the wealth of information pertaining to this topic on this board. Has anyone ever posted a method to check the operation of this part.

Vincent

By the way did if anyone knows of a good diagnotics tool that is somewhat reasonable in cost i would appreciate hearing about it.

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Vincent
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1997 C230
1995 C280