Hey guys,

I'm one of the evil step-brothers (I drive an SRT-6)

Although it isn't a C32, it is powered by the same powerplant so I thought I'd ask this question. Prior to asking, I did a search and saw that the problem has occurred a few times but didn't find an answer.

So, here goes:

Sometimes in the morning when I head out to start the car, the car will crank for 7-8 seconds before finally 'firing'. When it DOES fire, it will often stumble/run rough for a few seconds before finally 'clearing up'. I can 'clear up' the idle on my own by touching the gas pedal...
From what I have read, there is a 'cold start auto choke' in these cars that may cause a rougher than usual idle immediately after a start? This problem occurs in temps ranging from 85* to 45*, so I don't think it is related.

Also, there are times when I will take the car to lunch - run inside, grab a sandwich, then 15mins later go to start the car and it will occur. At this point, the car is still 'warm'. The car will crank for 7-8 seconds, and then finally fire.

On three or four occasions, the car cranked for 10+ seconds and never did 'fire'. The car just gave up, and I had to remove the key, re insert it and re-crank it - at this point it fired right up and drove fine.

The car is not lacking power or performance - it just acts as if there is a leak-down somewhere in the fuel system. I did some research and there is apparently a check valve that holds fuel pressure after you turn the car off so that the car can fire up instantly when you turn the key.

Has anyone had this issue on their C32 or SLK32? If so, what did you do to remedy it?

Although our cars are MB powered - they are clothed with Chrysler skin and badges which automatically makes the service TERRIBLE. The dealer told me the starting was normal and they could not replicate the problem. There is nothing more embarassing than putting the whoopin' on an LS1 Trans Am, then pulling into the gas station to talk to the LS1 driver only to try to start your car and have it crank for 15 seconds as the LS1 driver looks at you like you're lame.

Thanks in advance!
SQ

 

I seem to remember somebody posting here with the same problem - I think the issue was a faulty fuel pump.

 

I have talked to a few people who had a similar issue and someone said a fuel pump seal of some sort which allowed air into the system.

I am basically making a list of anything that it could be so I can hand it to my dealer and tell them to fix things until it is cured. The hard part is getting the problem to occur as it is very intermittent and you never know when it will happen.

Thanks for the info!
SQ

 

How is the fluid level in the radiator? I'll explain what I'm thinking if it has ever been low and you had to refill it.

How many miles are on your SRT?

The C32 and the SRT6 do not share the same fuel pump. So, we might not be of much help to you if it is fuel related.

Also, do you have a modified intake?

 

The car has 3600 miles on it (that's 36 hundred, not thousand). The car was bought 'new' in July 2007 with 14 miles on it - so, in other words, it was built in early 2005 and sat for a long time (two years +) prior to being driven. I have heard of this causing issues with seals in some instances.

The car is stock with K&N Drop-ins. Coolant level was normal last time I looked, but it has been a month or two. Should I check the reservoir or actually inspect the radiator?

I had a SL55 Y-Pipe on it for a short time, but it showed a loss of power on the dyno so I pulled it off. All back to stock now, except the filters.

I was going to get a LET setup on it, but with it acting up I don't want to modify it until I am pretty certain I will be out of the dealer for a while.

Thanks for the help.

 

Have you tried fuel injector cleaner? I know it's a long shot, but it does sound fuel related. I would throw in a can of FI cleaner, then have the dealer replace the fuel filter and see if the problem ever comes back.

I wouldn't worry about the fluid level for the radiator. There is a warning light that would alert you if it were low.

I would focus around the fact that the car wasn't driven for 2 years...this can kill a car quick.

 

I haven't tried any injector cleaner, but I can give it a shot. I would think that it has to do with priming/pressurizing the fuel system, or a lack thereof.

I just looked at the coolant again and it appears normal.

Also noticed the typical driver's side valve cover leak - doh!

I was hoping someone who had the issue would let me know what their dealer did to fix it. I did find a section in the repair manual regarding this fuel pressure valve that holds pressure in the injectors/lines when the car is off. You can test it by putting a gauge in-line and letting the car sit without running for 30mins and see how much pressure you lose...but I don't have the tools to do it and I don't think my dealer will do it just because I said so - they need a reason to work on it.

Thanks again.
SQ

 

Shawn,

I've also got an SRT-6 with this EXACT issue. I haven't really thought too much about it (had the car 3/4 weeks, and I've only been driving it on the weekends) so if it happens a few more times, it will definitely be going to the dealer.

I assumed it was from 87 octane the dealer filled it up with before giving me the car (dumbasses). I've run 2 tanks through it and 2 bottles of octane booster, so I was going to hold out before declaring an actual mechanical issue.

I'm totally expecting the same run around you are anticipating from the service department. NOT looking forward to it.

If you get the issue figured out, shoot me a PM!

 

try a seafoam treatment get 3 cans once in the gas tank 1 through the vac lines that go to the intake mani finaly half to the crank case replace youre plugs and do a oil change in 300 miles

http://www.youtube.com/watch?v=nqTIA...eature=related

http://www.youtube.com/watch?v=Mjc2T...eature=related

http://www.youtube.com/watch?v=gGTg5...eature=related

http://www.youtube.com/watch?v=P-4Ef...eature=related

 

try all the snakeoil (FI cleaner, seafoam, etc.) Then go back and get the root cause of the issue fixed at the dealer.

 

I have to agree with Kar don. There's not a chemical fix to a mechanical problem. You appear to have a fuel delivery issue, and as was mentioned somewhere above, it seems the car is not holding fuel pressure in the lines upon start up, and takes a second to prime back up. It would seem if there is a fuel pump problem you'd experience issues once you're driving down the road as well. However, since this appears to be a "start up" issue, it leads me to believe you've either got a vacuum leak of some sort, and/or a pressurization leak. Maybe even the Idle Air Control Motor could be faulty. There are numerous possibilities for what's causing this. I don't know anything about your fuel system specifically, but I would pursue things related to fuel pressure at start up. ie, Fuel Pressure Regulator, and other components that help prime the system for startup.

It would appear your car is still under warranty, so I would absolutely make the dealership fix the issue. If they can't duplicate it on their initial attempts, then make them keep it overnight and try again the next day. If it does it to you, it'll do it to them. Also make them give you a rental while they're scratching their heads trying to fix yours.
It's sad these days that the service technicians at most dealerships know as much about fixing cars as do the counter people at AutoZone about selling auto parts ------ as in, they know NOTHING!

 

dont use seafoam. With only 3600 miles on the engine, the seals haven't fully broken in yet. Seafoam was primary designed to get rid of carbon deposits in your engine. Since you have 3600 miles you shouldn't have any carbon deposits yet.

I agree with the other guys, its a fuel issue. You can try upgrading your spark plugs and see if it helps.

 

Thanks for this post! I remember someone having a similar issue and it was the throttle acutator causing the problems.

 

No offense meant to TemjinX2's recommendation, but upgrading spark plugs on a basically new vehicle is not the answer, nor will it have any affect on the problem at hand. He obviously has adequate spark since the car drives down the road just fine and only has issues at startup.
"Upgraded" spark plugs are the most overrated performance gimmick in the automotive industry. The majority of "upgraded" or "premium" spark plugs simply infer they'll last longer than a standard conventional copper plug. Hence why car manufacturers are now using higher grade platinum plugs in vehicles, and advertising you can go 100k miles before changing them (which is also not a good idea). In any of my "race" vehicles I always use a good ol' standard $1.19 Autolite copper plug, because it actually gives me the best spark --- it just won't do it for as long as a platinum, or iridium, etc. Hence why I change 'em nore often. And, I wouldn't recommend that for our MB performance vehicles, however the plugs that come in the car are more than adequate for 50k+ miles.

Now, I'm not recommending someone go out and buy the cheapest plug available, but I am saying that paying $15 per plug is not going to yield you any better performance than a typical $2 platinum or $4 double platinum, or the likes. But I digress...

The bottom line here is --- Spark plugs are not his problem. Your Seafoam comments are valid though. Unless he has badly clogged injectors or other carbon-like buildup internally, he doesn't need to waste money on chemicals that are not going to fix his mechanical problems.

 

The car ran 13.2 at 106mph with a bad 60ft, and dyno'd ~300...so it seems to run just fine. You are correct, the only issues are at start-up.

I am probably going to try a new dealer soon and will report back what they find.

SQ

 

also check out the crank position sensor.

 

The CPS is on the short list - however, I have read that if this is bad the car will often times not even 'crank'. The car has no problem turning over, it just does so for way too long.

I have captured it on video a few times, but the sound on the video is so quiet it is hard to tell the car is cranking.

Thanks again,
SQ

 

if it's the CPS when it's out of wack the car would crank, but would not start.

but check it just to be safe anyway.

 

Yeah don't use seafoam on an engine with few miles on it, you'll just be wasting a can. Definitely works better on older cars that have carbon deposits ("working better" meaning you get a more interesting smoke show out the tailpipe haha).

 

Hey guys - captured the hard start on video - thought I'd share:

See it at the link below

http://www.youtube.com/watch?v=AXv61x3gz7s

 

FYI: Car has been fixed.

There is a check valve in the fuel pump that holds line pressure between the pump and the injectors when the car is NOT running. This check valve is suppose to hold this pressure indefinitely.

A pressure test on the fuel rail showed a complete leak down (0 pressure) in less than 10 minutes. Therefore, jumping in the car and hitting the key would sometimes take forever as it had to prime the car more so than it would if there was already fuel in the lines.

The fix was a complete fuel pump from the dealer - although I'm not sure if you can fix just the check valve.

Thought I'd let you all know due to the fact that you were courteous enough to throw out some ideas.

Keep it on all four!

SQ

 

glad to hear it's fixed.

 

I just had the same problem with my 1998 w210, I had it fixed by replacing the fuel filter which includes the so called check valve, the filter is located near the back/left tire so the car had to be lifted up. total costs: $43 .. many thanks for the thread starter because it gave me idea regarding my long embarrassing cranking time.