Hi everyone, I would appreciate any help. Bought a 92 300ce with 106k miles 3 weeks ago. Love its classic lines and drive. Previous owner once stationed in Kuwait, drove only 6k in past 2 years so car sat for months. Since 100k previous owner got new trans, distributor cap, rotor, radiator, trans oil cool line, thermostat, vaccum supply hoses, ignition wire set and coil, fuel injectors, spark plugs, etc. etc. I had 2 new auxiliary fans installed last week.

Here's the problem. Engine sometimes misfires at low revs and at standstill. When accelerating, car hardly moves as if no fuel is fed then once past a certan rev around 2000rpm it goes smooth after a little jerk. Gets worse when a/c is on. Occassionally hard to start too. But when engine is cold like first thing in the morning, car starts, runs and drives terrific then problem comes on when temp goes to 80-100F. Also can feel very slight shaking when idling (as if sitting on a massage chair on low). Was told it needs new engine mount? Spark plugs on car now is Bosch F8DC4. Per MB dealer it is the right plug but manual says F9DCO. Need also reliable and honest MB mechanic in Dallas. Thanks a lot.

I had the same problem with mine...turned out to be plugs and the catalytic converter.

I use Jose Duran. He is at 35/Walnut Hill area. 214.351.4254.

He has been great with my car and MUCH less expensive than any place I've found.

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R Talley
88 BMW E32 735i (make it go away)
95 Volvo 960 "Inga" (valve problems)
95 Nissan Maxima (the indestructible)
89 Ford Ranger XLT (ugliest truck in the South)

Check the resistance of the temperature sensor that feeds the ECU (make sure it's not the one that feeds the Temperature gauge).

The figures should be in the Haynes Manual.

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Paul Gibbons
'93 320CE
'73 Jensen Interceptor (Resting)
Giant Full Sus Mountain Bike

Resistor ends on the spark plug wires. They are about $60 at the dealer. I can't find on line. Mated with correct plugs will do the trick.

Regarding the mechanic, I'll let you know when I find one.

I had exactly the same problem yesterday nite, Tuesday, with my 87 300e. (I had filled up the gas tank Sunday nite with Mobil super.) I checked the spark plug wire connections & noticed the wires were really hot, too hot to touch. I had just completed a 30 minute highway drive averaging 70mph. I also found when I lifted my foot off the accelerator for a second the car ran smoother, as evidenced by the economy gauge needle moving to the far left, the best reading. This suggests to me a fuel flow issue, maybe fuel pump relay, which is discussed as a cause in thread 36327, entitled "300e won't start. Fuel Pump? How to check?", which you should read.
BTW, should the spark plug wires get that hot? Does it suggest resistor end problems?

I bet resistor ends. Had similar trouble, advice from this foram solved problem. New resistor ends and the problem disappeared.

Went to Duran as recommended. Fixed slight fuel leak in the back and replaced oxygen sensor. Replaced plugs (F8DC4) though existing were only 5k old. Problem still persists, and now has slight lag in acceleration even if already cruising at 40 and above which did not exist before. New iginition wire set ($200)was put in 5k ago. Can they go bad that quick? Had similar problem with my 89 300e (166k), and was never able to get it fixed so ended up selling it last year.

You didn't specify that the resistor ends were replaced in your post. Do you know that in fact they were replaced? I can envision the mechanic reusing the old ones if not specifically told to replace.

Replacing the resistor ends seems to be the popular solution. But pardon my ignorance as I am not mechanically inclined, doesn't the ignition wire set include the resistor ends? While I can't attest to it, previous owner's receipt show a new ingnition wire set installed 5k ago. Anyhow, am bringing car back to Duran as he himself is disappointed he wasn't able to fix it the first time. Will relay again resistor end possibilities.

Could it be a dirty fuel filter or moisture in your fuel tank since it sat for months in a garage?

It won't hurt to put in a bottle of Fuel System Treatment.

Good luck.

Yes, I did put a bottle of fuel injector cleaner but didn't help. Fuel filter and regulator both checked OK. There seems to be a burnt smell though not as bad before the oxygen sensor was replaced. Duran is a 2 man operation and has 6 other cars with sure fire fixes to work on. He can't give me definite answers. Thanks for all your help people. I didn't realize there is a wide universe of MB enthusiasts out there. This is becoming a challenge but I'll get it fixed and will get back with the fix. By the way, if anyone is interested the car is for sale for $9.5k. Parts and labor spent since 5k ago total almost $7k. You can email me at grouppacifica@yahoo.com if interested and I'll email full info and pics. Roland 214-684-6857.

Hey MBRookie, I wanted to clear up a small thing. . .

That "Economy" gauge is completely useless and doesn't say anything meaningful in diagnosing problems (unless you have one hell of a bad vacuum leak).

The gauge isn't telling you how much fuel is being sent to the engine, it just measures engine vacuum. When you open the throttle, there's less engine vacuum and the needle goes up. When you let off, the engine is sucking air through a smaller opening, creating more vacuum, and the needle goes down.

Think of it as the mechanical equivalent of your wife complaining about your lead foot.

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Jay
1998 S320

That's probably why MB took out the economy guage. Mine doesn't have one. I understand vacuum is involved in almost all the power stuff in the car such as trans, power locks, steering, etc. Am a mechanical moron, don't have a clue how it works. My son recently graduated cum laude BSEE, maybe he can educate me on this. Anyhow, many many thanks to you people out there for your insights and care specially to 95E320cab who called and offered his valuable time to help in person change the resistor ends. I was floored by his generosity. I will change the resistor ends and will post the results.

Is there a similar forum on Acura cars? My wife drives a 97 RL with 84k. Yesterday, after a sudden brake to avoid an accident, there now is a grounding noise when braking a little harder than normal. Noise doesn't sound on normal braking. Could this be a simple brake pad replacement?

Hi folks, just wanted to give an update. Per coworker recom. brought car to Louden Motorcar (972-241-6326) reportedly won several awards in service excellence & voted as Bosch's #1 service center in the western US. Replaced EGR valve, reference sensor & water temp sensor. Problem is gone but very costly over $900 ouch and ouch some more!! Hope to enjoy trouble free miles. Wife still prefers reliable Japanese cars.

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The car looks fantastic. You will love this car. Don't throw in the towel.