I've never had any cold start problems. Well, maybe a little bit in my original computer's final days. New computer fixed all of my recent problems.

The computer is plug and play. Just plug it in and go. Probably the easiest thing to swap out in the whole system.

mike,
The eha reading is not what it should be and your potentiometer is probably fine, unless it is circuitry as you will clearly see the wearing if it is a bad. So we need to figure out why you are not getting the right eha readings, or the duty cycle. Somewhere the loop is open, now we just need to figure out where. T

__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

No change, as we expected. Same bahavious as before. Lined it up exactly to the previous pot's posistion. Still 10% once she finally gets idling.

Well at least I can cross the pot off the list, and it wasn't too much trouble. Hey at least I learned something new

My symptoms are the same as brew's for the most part. The bad cold start I have has just started in the last week. Before that I was seeing the proper numbers after the car sat.



That's good news.

What do you guys think- more diagnostics or should I track down a cheap (used) ECM?

Mike

http://www.car-part.com/cgi-bin/search.cgi

The above link shows some used ECMs available throughout the country. I'll search locally first.

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

My ECM readings and EHA readings were virtually identical to yours except that I was getting a variable reading around 10% and you are getting a fixed reading when the engine is running.

Did you check the throttle position sensor?

Brew-

I think im going to go for the computer- it seems my symptoms are identical to yours (I watched my DC again and I DO get fluctuation around 10%, just sticks sometimes).

You say you tried to resolder yours- were the cracks/broken/corroded contacts obvious?

I'll post a "WTB" post in a couple of the forums and see if I can pick up an ECM cheap.

Mike

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

Actually, the board looked perfect. No obvious problems at all. I assume it is a bad component but nothing "blew up".

Click here to find an ECM: http://www.car-part.com

Good luck!

Ordered the new ECM on monday morning, so it should be arriving sometime this week.

I've been reading up in the manual about this part, which MBZ calls the "ignition control unit." Not sure of its function during cold start, which has me a bit worried.

The part number on mine is 008 545 96 32. Ordered one from a '90 300se so it should be the same.

Will post results tomorrow hopefully.

Mike

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

mike is that the ezl you ordered or the ecm? the ke control unit is 0115452932 i think. the 0085459632 is the ignigtion control module or ezl
m.

__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

The KE unit is the one I replaced. It is the one you've been reading the duty cycle from. I don't have the part number in front of me but it's located right behind the battery. The EZL unit is on the left fenderwell.

At least that's where they are on the 300E

That number 008 545 96 32 is for the IGNITION control unit and has nothing to do with this thread that I can see. We have been discussing the fuel system control not ignition.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Hi guys

I ordered the ECM. I mistook the EZL for the ECM when I was looking in the engine bay today.

Behind the battery- Is it the part that fits into the brass clip, which has wires coming in and out? What is the part with the buttom which is depressed when the hood is lowered?- looks like a diagnostic port of some sort.


Thanks again, Mike

PS- Can someone tell me if there is a section in the manual which discusses the ECM and its functions?

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

Could it be the switch for the alarm? Does it look like the switches on the door jambs?

I read up on the alarm system in the manual and it shows an alarm trigger under the hood. I couldn't find anything on what the diagnostic port does.
Wow, the alarm system looks more sophisticated than I thought- level sensors to prevent towing?

Well, hopefully the ECM will arrive tomorrow! Looking through the archives, I find very little info on this part. They must have a very low failure rate.
Mike

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

well the part still hasn't arrived, but i have the afternoon free so I did a little experiment.

I unhooked the battery last night and then rehooked it today. Car started right up and then numbers (at least at pin three are normal again (49.9% at warm up)) Didn't check EHA.

Is this a clue in the puzzle? I will go run a few errands with the car and see what happens. What so you guys think?

Mike

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

Isn't that the same reading you were getting before? I thought you had to drive it a while before it started the 10% stuff. Or was that my car that did it that way?

Disconnecting the power had no effect on mine.

Anyway, 49.9 is the correct reading right after startup, before it goes into closed-loop operation.

What happened when you drove it?