peanut

ok I can see your predicament and it can't be easy . You have the same problem as I have trying to do this over the phone and by email

I would suggest that you request your indy check the following.
1. battery fully charged or use battery booster or jump leads from a good battery in other vehicle The engine must turn over at a minimum of 225rpm for the ECU to give you spark and fuel delivery.
2. Do not fit the DME relay!....Use only the 3x wire bypass in place of the DME relay. At least you will then have a guaranteed 12v+ supply to the ECU and Fuel pump. Instructions on how to do this are on Clarkes garage website.

3. Make sure when cranking the engine that the tach needle jumps a little. The movement of the needle is very slight and needs careful watching .

Spray some ' Easy start' or whatever you call it in the US into the air filter whilst cranking to aid starting.

If they do not see a spark at the plugs when cranking then I'll supply my email address for them to contact me directly but bare in mind the time difference between the US and the UK .
Its nearly 8AM there in New jersey but its 1PM here in the UK so contact time fot your indy will be between 8AM and 6PM your time by which time I'll be going to bed hopefully

sweet928

Thank you very much. Spoke to the INDY. He hasn't had time to really look into the car still, but he assured me he's not going to charge me at all for any diagnostics. I explained everything I learned here and supplied him with the instructions for the relay jump and explained in detail about being fully charged, etc. Hopefully he will get to the car soon. Will advise outcome when there's news to report.

sweet928

INDY got it started by tapping the computer. It's running intermittently now by knocking on the computer.

John_AZ

There are a few threads on resoldering the DME to cure bad/aged solder joints.
The '87 924S uses the ...04 (944 618 121.04) DME



Watch for a spare DME on ebay. Usually from $90 to $150 used.

Member "Specialized ECU" has an exchange program and 5 year warranty.
http://www.ecudoctors.com/

J_AZ

sweet928

Thanks. I'm waiting for the INDY to pull the computer to make sure of the exact Bosh Part #. There's apparently three different Bosh model #'s for MY. ECU Dr said they all will work but each has a slightly different fuel/air mixture. They strongly recommend staying with the Bosh Part my car uses now.

Seems there's a few sources for me to pick from;

$275 for a swap with ECU Dr and 5 year warranty BUT a core charge of 400 which might not be fully credited - depending on issues/condition of mine when sent back. OR I can try one of the Ebay guys for @150-175 with a 30-45 day warranty and no core exchange. I'm leaning this way as that gives me my old one as a spare to try to attempt to open and repair too.

BTW, Anything cheaper is zero warranty or not even assurance that they work at all.

sweet928

Anyone ever use these guys? They will diagnose for free. I'm thinking buying one off Ebay and then sending mine to them for potential repair and spare/backup.

http://www.autotekcarparts.com/?Page...77&PartID=3594

John_AZ

Not familiar with AutoTek.
A RL sponsor is more credible.

The INDY is correct that there are a couple of DMEs that may work. I gave you a photo of the DME specific for the '87 924S. I bought my '87 924S in '98.

EDIT. Bosch has a web site that details every Bosch part in the car:
http://www.bosch-automotive-catalog....hangeCountry=1

Post a WTB on Pelican "Used Parts for sale or wanted".

http://forums.pelicanparts.com/porsc...s-sale-wanted/

J_AZ

white924s

Glad to hear that its just the DME and not something more complex to fix or expensive to replace.

If you need another recommendation on where to go to get the DME fixed, you may want to call the shop that fixed mine, Rennwerke Porsche (914-592-4006). The owner, John "Cheech" Fernandes, would know where he sent my DME to be rebuilt, and I believe the rebuilt DME comes with a warranty. Rennwerke has done a lot of work on my car, and I have been very happy with their work.

sweet928

New DME arrived today. Dropping it off tonight. Haven't even driven the car more than once since I got it. Hope this works.

simxxi

Just got my ECU back from the ECU doctors. No fault found. Operates perfectly on the bench. I am getting fuel at the rail but fuel pump only runs while cranking engine. Not in the run position. My car has not run in the last six months after replacing head gasket, water pump, and resealing the oil cooler. I've been out of town frequently. So I guess next step is to drain the fuel and try a fresh batch. I thought the fuel pump primed the fuel rail when you first turn the key on. Mine does not. I did read the Boshe book a couple of years ago very detailed theory of operation. Let you know when mine is running again.

sweet928

Mechanic hasn't installed the DME yet. Hope your experience doesn't mirror mine.

sweet928

DME is in and car is running! Whew. They are just doing the shift linkage now - which was the reason I drove it in in the first place. Just in time to start racing it!

white924s

Fantastic news! Congrats on getting it running again and I look forward to seeing you at a PCA event soon!

FYI, if they can get it done by this weekend, Metro NY is having an autocross on Sunday out on LI. I think I may go (time/weather permitting) to give my car a shakedown test before my DE season starts in a few weeks

white924s

I thought that the pump primed the rail too, but another poster in this thread, peanut, said otherwise so I could be wrong (I haven't had the opportunity to verify it on my car, and I don't know if early/late DME's may be programmed differently). If your DME is working on the bench, but the car won't start, one quick/easy thing you should double check (if you haven't already) is that the tach bounces when cranking. If it doesn't, that could signal a problem with your reference sensors, which is a somewhat common issue on these cars. If it does, then unfortunately the problem is probably something more complicated.

sweet928

Just heard from the shop. They reported the car ran with the new computer and now it's not running. They seem more capable then I first thought and have been running the multi meter all over the car, but for some reason the signal is not passing though the computer as it should. He replaced the ref sensors because he said they were cheap and measured poorly on his multimeter as well as the coil too. He also said the fuse pannel looks like it's in very good shape and they don't see anything wrong there. I'm really dissapointed to get this news. The shop is being very nice and told me they won't charge me for all the time they spent - maybe just a few hours of labor charge despite having put much more into it. The shifter is sorted out now which is why I brought it in in the first place. They tried jumping the relay. The battery is fully charged (actually at 14v).

Any thoughts what could be giving me intermittant start? I guess the replacement DME could be bad too, but the shop owner says he very rarely sees bad computers unless water is present. He said my floor was a little wet on the drivers side but water doesn't seem to be entering by the fuse pannel based on the condition of the fuses and pannel itself - which he dropped to check behind too.

Any ideas from the experts here?