ausgeflippt951

Hi all --

The part number on my DME is 951.618.121.01 (Bosch number 0 261 200 053).

I noticed the part number described in my factory service man for the 951 DME is 951.618.121.02 (Bosch number 0 261 200 075).

What's the difference?

I do know my DME is not the original unit (it says "ebay" on the side).

Thanks.

xsboost90

i have an -02 from an 86 if you need one...

ausgeflippt951

Today I put my DME into a working '86 951 and all worked fine; what could the difference be tho?

bjzorn

how old is the factory service manual. It looks like its just a supersession. to me.

Tom M'Guinn

So, that would strongly suggest your DME is ok. What are your symptoms?

ausgeflippt951

Yeah I've been battling a couple problems: low boost (1.3 bar gage) and a hiccupping involving zeroing of the tach. See my other threads for complete details, but long story short, I was nearly certain the problem of the hiccupping was the fault of the DME.

Well, unfortunately the hiccupping is only intermittent and when I plugged it into the good car, nothing went wrong after about 5-10 min of driving. Unfortunately the car was a customer's car, so driving for an extended period was out of the question.

I'm now looking into the ignition coil; haven't yet inspected it.

ausgeflippt951

i was looking off the turbo service manual, and next to the window (page 28.2) where it says the part number, it then states "Installed as from 11.8.87."

Supercession?

ausgeflippt951

I've got the low boost "solved" by mechanically bypassing the WG w/ an LBE. But I'd like to solve it for real.

I've already replaced the CV w/ a used unit which the seller swore up and down was a good unit, but I really can't be sure. Also, the last thing I haven't done to solve this problem is to replace the little knock sensor itself. So, I'm thinking of replacing both because I only want to take off the intake manifold once.

Tom M'Guinn

Have you wiggled the ref sensor wires while the car is running?

bjzorn

you have an 86 car with part number 951.618.121.01. as of that writing the part number was 951.618.121.02 or superseded to an updated part. No big deal Porsche supersedes there part numbers all the time. That just means they made an improvement to the part and therefore updated the part number. It will work

ausgeflippt951

Cool thanks. This is what I thought.

Yeah I've even replaced the speed/ref sensors but alas no dice...still haven't gotten around to checking the ign coil yet tho.

Tom M'Guinn

Have you inspected the harness connectors closely at the ref sensors, injectors, air flow meter, throttle position sensor, and at the DME and KLR itself? Also, if you have a datalogger, they can be very useful in trapping electrical glitches. I found a frayed wire that way once.

Have you checked to see if the AFM is sending a smooth (non-jumpy signal)? When the variable resistor goes bad inside, the signal can jump around.

ausgeflippt951

Yeah I've checked the AFM. All of the harnesses look fine except for the injector harness. The outer insulation is chipped away at places but the actual wire insulation itself is fine.

ausgeflippt951

Just checked ign coil and plug wires. See my other thread I started for details...what should plug wire resistance be???

I started a new thread for making future searches easier.

Luis de Prat

Not necessarily. The late DME in my 951 would work fine until after about 45 minutes and then wreak havoc making the car stall, buck and backfire.

This was extremely tough to diagnose and only after I replaced the DME with another unit did the symptoms go away.