FLYNAVY

Gents,

Sorry if this is a horrendous "do a search" kind of thing, but I can think of a lot of reasons for the issue and was hoping someone could point me in the right direction, particularly if there are some common issues. I don't have a whole lot of experience/knowledge of the w203 as a whole.

Anyway, this afternoon, after about 30 mins or so of stop and go rush hour traffic, stopped to get some food. After we were done, went back out to the car, and tried to start it. Very solid cranking, so I don't believe there are any issues with the battery/starter/etc. It also seemed as if the spark plugs were firing just fine. During cranking, while it obviously did not "catch" or fire off so to speak, I got the CEL and DTR dash lights. Of note, car had been sitting for about 20 mins, but engine was still warm, and it was a pretty warm day. After waiting another 15 mins or so (after numerous start attempts), and pondering what to do, I gave it another try and it fired right up. Drove home, and once safely in the garage, shut it off and tried several other starts. No hiccups at all this time. CEL remains illuminated, as I would imagine it would. Also, possibly of note, climate control was on auto, AC on when I was having trouble starting. I killed it prior to the later attempt that worked. Once back home, it started just fine with the AC turning.

So my question is, with these symptoms, what say ye? Crank position sensor? Fuel pump relay (I remember that was a common w202 issue)? Fuel pump itself? Those were my best guesses at least. Background of the car, 2003 C240 Sport Wagon, ~83k on odo, always been in the family since new, never had any issues whatsoever.

Thanks guys!

kanadian

First things first, get those CEL codes as it might lead you to a solution. Can you hear your fuel pump priming? If it happens again listen for it before cranking the engine.

FLYNAVY

Yeah, unfortunately nowhere was open at that time of day to run the diagnostic code(s), and I don't own OBDII gear myself, so that will have to wait until later in the week when I have time to take it somewhere. I'll try and listen to the pump if it happens again though. Where is that located on a 203? Left rear axle area-ish?

samaritrey

Classic CPS symptoms very easy job if you have small arms/hands. I did one for a fellow member in around 15 minutes once the engine cooled down. Plenty of DIY guides on it around here but the basics are take screw out pull like hell on the sensor. Use the OEM/OES part so you don't have to do the job again any time soon.

FLYNAVY

Thanks for all the advice guys! Actually had to drive it a bunch and wait for the no-start to occur again, since the CEL went away really quickly after the first event. Checked the codes, sure enough CPS. Got a new sensor, and since I am currently on 2 weeks of paternity leave, I should have a bit of time to do this, and all the other maintenance projects that have been stacking up over the last few months.