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Greetings - I searched and couldn't find a thread for this exact symptom. Thanks in advance for any ideas you have! 1998 C43 144K...traveling at 70-75 on I-90 every few minutes the engine will hesitate for about half a second to 1 second, the engine light flashes then it goes back to running great. Happens at cruise and acceleration, randomly. At a stop light the engine will sometimes quit. Thinking these 2 are related. Fuel filter? Fuel control module of some kind?
Sounds like an intermittent electrical connection in some area related to the Engine CPU. Maybe a loose ground, or a corroded connector. Time for a spring cleaning of the electrical system underwood in particular.
98 C43, 15 Alfa 4C LE, 18 Tesla Model 3 DM Perf, 08 Duc S1000, 02 Duc 998, 98 Duc 748, 01 Miata
Have you used a scanner to see if anything is stored from when the engine light flashes? Intermittent issues are always the toughest to solve. A fuel filter would manifest itself when fuel demands are the highest, so at closer to WOT. If the issue seems completely random and not load dependent, that wouldn't lead me to the fuel filter. That being said, I would never discourage routine maintenance :-)
Hi all thanks for your fast responses. No lights were on but I did scan the codes just in case as Eric suggested and there were 2 there: 1) P0130 oxygen sensor circuit bank 1; sensor 1 and 2) P0455 evaporative emissions system leak detected (gross leak/no flow). New spark plugs and wires 12 months ago. New engine and trans oil 60 days ago. I'm an average mechanic can change water pump/oil/etc... Please share suggestions if I can buy parts to remedy the codes or if I should take it to a shop? Thanks again for your experience and knowledge...
Last edited by Maetar; Jun 17, 2021 at 07:31 PM.
Reason: typo
98 C43, 15 Alfa 4C LE, 18 Tesla Model 3 DM Perf, 08 Duc S1000, 02 Duc 998, 98 Duc 748, 01 Miata
Check your gas cap? Any obvious disconnected vacuum lines? If nothing obvious there, a smoke test can help find an evap leak. On the oxygen sensor, replacing that sensor may be the most straight forward first pass.
Lol I've had this exact problem before,but my engine never quit. my issue was a spark plug boot came loose. I'd recommend taking all the wires off the spark plugs and reseating all 16 to see if that fixes it
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12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Originally Posted by brad_c43
Lol I've had this exact problem before,but my engine never quit. my issue was a spark plug boot came loose. I'd recommend taking all the wires off the spark plugs and reseating all 16 to see if that fixes it
I would add to check also the connection to each coil
I took off all 16 spark and coil plugs, put them back. None of them seemed to be loose.
Cleaned any electrical connection/ground I could find under the hood.
Can't find any vacuum lines to the gas cap? Looked inside trunk, wheel well, can't find any, pls share advise how to find them?
Also to clarify, it seems to only happen while or just after driving at I-90 speed. And acceleration/WOT not a problem, still plants you back in your seat and makes sweet sounds getting up to 80
Oxygen sensor from MBenz Liberty Lake is $357. Once I find/check the vacuum lines I'll take it out and report back before dishing out the dough.
98 C43, 15 Alfa 4C LE, 18 Tesla Model 3 DM Perf, 08 Duc S1000, 02 Duc 998, 98 Duc 748, 01 Miata
On the gas cap front, just making sure that it is on tight. The vacuum line reference was to the various vacuum lines in the engine bay. Making sure none have popped off or are obviously cracked.
In regards to buying parts, I would look at places like AutoHausAZ, FCPEuro, Pelican, ECSTuning, etc versus buying from the dealer. They often have the OEM part plus alternatives. If you did need dealer parts, Mercedes Benz of South Atlanta used to have a good online shop for OEM parts at mbpartsworld.com but the banner at the top of the page currently looks like that site might not be a good option right now.
Hi all - I've been north of the border in Canada the last couple weeks, just got back. Found a vacuum hose that was rotten (see pic, the top of the hose seemed fine, when feeling underneath is when I felt the rot, seems like due to age/heat), replaced it with fuel hose as couldn't find the right vacuum size anywhere. Problem still happening. Ordered new gas cap gasket and oxygen sensor from autohausaz, will report back after I swap those out. Thanks again for your knowledge.
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