'87 n/a dme

[mytrplseven]

Does anyone out there have a working '87 DME from a manual shift N/A that they're willing to loan? I need to eliminate the DME as the possible gremlin in my stuttering acceleration issue I've been chasing for a year. I've changed and/or repaired everything else I can think of. I'll be willing to pay freight both ways. Let me know via PM if you can help. Part number: 0261200077.

Thanks in advance for anyone's help.

[djnolan]

Automatic and manual are the same DME. Hope you find a test unit but have you opened up the DME to look for suspicious cold solder joints using a magnifying glass? It is fairly easy to touch them up with a low wattage iron, just don't overheat anything. Reflowing the solder in DME's

[mytrplseven]

I looked it all over last year and found nothing suspicious. Was hoping to find a quick change unit to rule it out.

[djnolan]

Chased a similar problem last year and it turned out to be spark jumping to ground due to the excessive use of dielectric grease. Grease is an insulator and will block spark if used on spark plug terminals. It is only meant to be used on rubber to keep it from sticking. Replaced just about everything including a coil, DME swap and reflow in the process of learning this.

[mytrplseven]

Originally Posted by djnolan

Chased a similar problem last year and it turned out to be spark jumping to ground due to the excessive use of dielectric grease. Grease is an insulator and will block spark if used on spark plug terminals. It is only meant to be used on rubber to keep it from sticking. Replaced just about everything including a coil, DME swap and reflow in the process of learning this.

No grease on the new ignition wires; new total ignition system, new TPS, replaced AFM, fixed all (I hope) vacuum leaks, rebuilt fuel injectors and connectors, new ref sensors, fuel system filter, regulator and fuel pump and strainer, throttle body shaft seals, belts, water pump and rollers. Also, AOS seals and oil cap rubber seal. I still can't find why the engine stumbles on acceleration. Idle is rock solid. This is why I want to swap out the DME.

[S ECU Repair]

Seems like you pretty much covered all the bases.

Try this DME Follow up to check your electronics: http://site.ecudoctors.com/tech-data/DME-Diagnose-Follow-up-Forms.pdf

You have already done some of these but it is good to have a checklist to work off of.

Lastly when did the problem begin?

Did you at any point install a different chip or upgraded some hardware?

Have you done any modifications to the car?

[djnolan]

Well it will soon be running like a bat out of hell, rest assured!

[sausagehacker]

I had one a few weeks ago, unfortunately it already sold. I'll let you know if another one falls into my hands.

Have you replaced the fuel dampener? My understanding is that it works in conjunction with the FPR to maintain pressure in the rail. I have one from an early car, I don't know if it's the same spec as the late cars. Bosch part number is 0 280 161 015, and if you pay shipping I'm happy to send it your way. Just send it back if you still have issues.

[mytrplseven]

Originally Posted by S ECU Repair

Seems like you pretty much covered all the bases.

Try this DME Follow up to check your electronics: http://site.ecudoctors.com/tech-data/DME-Diagnose-Follow-up-Forms.pdf

You have already done some of these but it is good to have a checklist to work off of.

Lastly when did the problem begin?

Did you at any point install a different chip or upgraded some hardware?

Have you done any modifications to the car?

I've been chasing this issue for a couple of years. Part time driving while working on other parts of the car. I discussed coming over and you (Chuck) offered to swap one to eliminate the DME as the problem. I haven't been over that side to do that but will if I can't sort this out. The only mods I have done is to add extra pins to accommodate the RogueAnt MAF and chip mod I plan to buy, assuming the DME is otherwise healthy.

I pulled the DME again today to inspect for flaws in the soldering and add the pins. Also rechecked the TPS signal properly coming to the DME connector.

Car's back together and runs like it did before I pulled the DME. Thanks for the diagnosis sheet. I'll try to go through it tomorrow. This is certainly frustrating. My other two 944's ran great and I'm hopeful I'll get to the bottom of this soon.

[jem60]

Is issue at part throttle/full throttle or all of the time?

[mytrplseven]

Originally Posted by jem60

Is issue at part throttle/full throttle or all of the time?

During all acceleration from normal to WOT. Engine idles very smooth.

[djnolan]

For your snoring pleasure: Diagnose Engine Misfire

[POPS 83 944]

I have one laying around my storage I could dig out for you to use. Let me know

[mytrplseven]

Originally Posted by POPS 83 944

I have one laying around my storage I could dig out for you to use. Let me know

If it's for a pre-85.5 944, I don't think it's compatible. I know for sure a post-85.5 should work. I appreciate the offer. Let me know what the part number is and I'll see if it is compatible.

[mytrplseven]

Latest: Pulled the DME yesterday and re-checked the solder joints, FQS setting, TPS continuity at the connector and then, in anticipation of buying the RogueTuning MAF kit, installed the 4 pins necessary to update the circuit board to receive the 28 pin ECU chip at that time. When I'm sure that I have a "healthy" DME, then I'll proceed.

[mytrplseven]

Originally Posted by djnolan

For your snoring pleasure: Diagnose Engine Misfire

Thanks for the info. I went down the list and pretty much eliminated all the sources listed on the article. With regard to the possible head gasket, compressions are good and the spark plugs are reading a bit on the "lean" side. I think by the time I figure this out, I'll have become an expert on all the technical aspects of what makes this thing run right.

[marbleusmike]

Similar problem drove me nuts for about a year! And a lot of parts! Try dropping your cat down and running it… Mine was completely clogged with broken up Platinum debris. These cars are old and it happens! Engine just couldn't breathe! I took it off car and put a piece of pipe in it and banged it around and then put a hollowed out cat back on! Actually sailed through NJ DMV with flying colors to my surprise!

[POPS 83 944]

Originally Posted by mytrplseven

If it's for a pre-85.5 944, I don't think it's compatible. I know for sure a post-85.5 should work. I appreciate the offer. Let me know what the part number is and I'll see if it is compatible.

I have changed mine over, I know I have two newer style DME's I know one I have chiped with a Wilks chip and I want to say the other one is a 077 numbered DME. I will pull it out to check if you needed me to. But yes it is a newer style DME. If you like I could pm my cell phone number to you, I work 2-10 with weekends off.

[mytrplseven]

Originally Posted by POPS 83 944

I have changed mine over, I know I have two newer style DME's I know one I have chiped with a Wilks chip and I want to say the other one is a 077 numbered DME. I will pull it out to check if you needed me to. But yes it is a newer style DME. If you like I could pm my cell phone number to you, I work 2-10 with weekends off.

Sounds good. the one with 077 is the exact replacement for my '87 N/A. I'll PM you with my address and phone#.

[mytrplseven]

Originally Posted by marbleusmike

Similar problem drove me nuts for about a year! And a lot of parts! Try dropping your cat down and running it… Mine was completely clogged with broken up Platinum debris. These cars are old and it happens! Engine just couldn't breathe! I took it off car and put a piece of pipe in it and banged it around and then put a hollowed out cat back on! Actually sailed through NJ DMV with flying colors to my surprise!

I put a new magnaflow cat on a few months back. Part of the non-ending efforts to get to the bottom of this. Thanks for the suggestion.