Mercedes Benz SL500 R129 1995 - Missfire when hot - Fixed #
Posted by Viv Beel on October 16, 2009, 7:46 pm
Year of Manufacture *: 1995 Engine Code or Type *: 119.982 ( Optional ) Scanner used: launch
Hi, I'm new to this forum, wonder if anyone out there can help.
I have a 1995 Mercedes SL500 Type R129 in which has developed a miss fire when hot. Initially I checked the obvious and found both of the caps and rotor arms had been tracking, fitted both caps and arms (Beru), miss fire still there, then found one of the caps was faulty, replaced with new one (Beru), slightly better, checked leads and a couple had high resistance suppressors, thinking that this may have induced high KV's and hence tracking in the caps, replaced the leads, 1st set had 1 open circuit suppressor so returned leads to supplier and bought Bosch leads, dramatic improvement, no miss fire under load but when hot occasional miss fire at idle. Using the Launch X431 scan tool, no fault codes, but cannot get any live data (management system Bosch LH1 doesn't give any live data). I am now beginning to go bald due to much pulling of hair, any ideas please.
Viv, It is not clear from your post whether you have serviced the spark plugs or not.I would get it checked on an ignition scope to find misfiring cylinder.
Fixed #
Posted by Viv Beel on October 17, 2009, 5:00 pm, in reply to "Mercedes sl500 R129 Missfire when hot" Message modified by board administrator October 24, 2009, 1:06 pm
Update on the SL500,
Fixed the fault, it turned out to be one of the "new rotor arms", it was a pattern part out of a BERU box, it just goes to show, use genuine parts, if a customer can afford to buy and run an SL500, he should be prepared to pay for genuine parts, a lot of time lost by me, and no profit in the job, I will know next time !
on October 16, 2009, 9:25 pm, in reply to "