I have looked but... Most common reason for acceleration miss -450SL - PeachParts Mercedes-Benz Forum

meltedpanda · #1 08-23-2007, 12:14 PM

Seems to be varrious factors that make the Djet system want to miss. Mine is a bit perplexing. It seems it only occurs after I first start and only the first few accelerations, then is dissapears and may reappear at random intervals. It almost always is there on start up , hot or cold. Seems to be fuel delivery related but sometimes she just purrs and comes off the stop like a rocket, other times, not so good, I am currently running some injector cleaner through it, as this car was not driven much over the last few years.
Ideas, suggestions

meltedpanda · #2 08-23-2007, 09:35 PM

Would running rich be a cause, timing?
What about injectors, seems likely, I can't be the only one with this issue can I ............

jdhill · #3 08-26-2007, 04:00 PM

How long has it been since the fuel filter was changed? That is generally the first place I look.

meltedpanda · #4 08-26-2007, 09:03 PM

I just changed it but I am on the second full tank of gas this car has had in the last 12 months or so, I am using some additives to get rid of any gunk, could that also give me these symptoms?

Roncallo · #5 08-26-2007, 10:06 PM

Generally for misfires under load, like in your case, I look to ignition. A good scope test will rule out your ignition right away. Since you probably dont have a scope, how old are your plugs, wires cap etc. Plugs are the only thing I would consider replacing as a shot gun approach. Wires and cap are very expensive and should last along time, a real long long time but your car is very old.

Fuel system is a posibility, that is why I wouldent go down the path as so many have in replacing a bunch of parts.

John Roncallo

meltedpanda · #6 08-27-2007, 10:32 AM

cap, points,, condensor all new, trigger points cleaned.
Wires were not changed but look great, I regapped plugs as PO said they were new, they are the NKG most suggest.
I am still leaning to fuel delivery, this morning it ran like a champ, no misses, it was cooler out so don't know if that is a factor.
Should I use a different plug? I have thought about that - cooler, hotter?

Thanks for the advice.

jdhill · #7 08-27-2007, 12:59 PM

I can highly recommend "How to tune and modify Bosch Fuel Injection" by Ben Watson. Step by step procedures for testing every component. I know it's available thru Amazon.