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· Registered
6 Posts
Discussion Starter · #1 ·
about a month ago I have been experiencing problems at idle very rough, and would slip when i mashed on the throttle more than a quarter. when it warmed up it would go away.

I took it in for a transmission service and oil change after, a week later i changed the spark plug wires to Bremi ones, subtle difference as the wires were old, but problem persisted.

Moved on to spark plugs (free from FCP EURO thankfully) changed those, fired up still no fix, matter of fact the problem is worse.

I scanned the car and was getting a cylinder 5 misfire p0505 i beleive and also and idle control something, can’t recall the exact code, will update with all codes present.

Anyway I was suspecting a vacuum leak but an indy took a look at it, the (ONLY ONE I trust, older german merc tech) and after plugging in his scanner he narrowed it down to fuel injector issue, which could explain the problem getting worse.

Fuel injector cleaner made a slight difference but barely noticeable.

Also last night I drove after a couple cycles to try to get the fuel injector cleaner through and the car kept giving me “convenience functions disable” and then when i turned the car back in after parking (had to go to the bank a mile away, it froze like it was dead, then suddenly restarted , clock moving backwards radio on when it was off before, and it turned on. Drive home ESP light came on, first time that happened.

Known issues: Leaking valve covers, plan to fix after i get this problem sorted
vent near gas fill up is stuck open so gas smell comes from outside

X pipe was just fixed after a bolt came lose and had it dragging

TLDR: Question: any ideas on what the problem is, anything to check, what could be wrong, and what to do next myself, if anything? I am moving so this is not the best time, and i gave my daily to my mom for pandemic issues. The engine has under 160k mikes and seems healthy when running proper. If this idle Issue can be fixed it’s an amazing car but I can’t figure this out. any suggestions? if it is fuel injector 5 what is reasonable for that fix, i saw the diy and it’s a little out of my pay grade and im tired of busting my hands past month.

ALSO, Anyone in SOUTH FLORIDA who knows or WORKS on these cars, please refer me or i will even help fix this issue, tell me what beer cigarettes and food you like and we can get to work :D

· Moderately subtle
14,337 Posts
You might look in our recommended service shops area. It isn't very active, but there may be shops that were well regarded that are still in business:

Just look through the thread titles for a city near you. There's only 4 pages of threads.
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