1985 Mercedes 380sl A million problems

[eltrapo67]

So I thought I had this figured out but nope I have a 1985 380sl. So I get 12.5v at the IACV when I switch the key to on but when I have the car running it drops to 0.06v or so, and as the car is running. I have the IACV disconnected and no rise or drop in idle even if I apply the 12v, its a new valve so I know its good and I here it click when I put power to it. I know I have a bunch of vacum leaks and i'm planning to remove the intake and reseal everything or most of it. But before I did that I wanted to see if I could fix as much as I could, My car has the oil switch and coolant switch as well as a thermo time switch, which I think the thermo time switch is bad because I checked ohms at hot and cold. The OVP is brand new also, the only thing I see affecting my idle is the frequency valve which does buzz. The main problem with the car is at start up, it fires up right away but shuts off if I apply throttle to it untill it is fully warmed up which leads me to the WUR. and I have changed 2 of those with junkyard ones and still have incorrect fuel pressure, I don't know if its the plunger in the distributor or pressure relief valve. I got a huge headache on my hands pretty much, but for now its a daily driver.

[meltedpanda]

PM me your email and I can send you some information of diagnosis of KJET , does your have oxygen sensors? LAMDA?

[GWT]

Did this problem get resolved?

[Diseasel300]

I went through this same issue with the 500SL a few years ago. MADDENINGLY FRUSTRATING to diagnose as the car would be fine, then randomly (and for no apparent reason) decide to idle at 1200-1500 RPM in gear at stoplights (made stopping in traffic exciting!). I had the same issue described above.....would have voltage at the plug for the IACV, but would randomly just disappear or give weird values. Applying a full 12V to the IACV with the car running would nearly stall it, telling me the solenoid was good.

In my case, it turned out to be the control module in the dash behind the glovebox. As with most of the PCB assembly on the car, the workmanship was complete $h*+. I resoldered every single pin on it and it's been 100% bulletproof every day since.

Since then, I've resoldered several problematic cards in the car and not had a lick of trouble from any of them I've repaired. Lousy solder joints seem to be exceptionally common (way more than they should be) and can cause all sorts of nightmare situations with intermittent problems.

[MBFarmer]

I had the same problem with my 380sl. Turned out to be a defective over voltage relay. One of the contact points were intermittalty making and breaking. replaced the relay and all is well. The car idles perfectly now.