Hi Guys,
Is there anyone out there with an 85 or 86 who may be willing to plug my LH and EZK computer into their car to see if it works? I had an engine fire and have replaced everything that was burnt but I still do not get any spark or fuel and strongly suspect that the computers got fried during the fire. I will gladly pay you for your time. I do not trust Partwerks for diagnosis as I have heard too many nightmarish stories about this outfit. It's a simple operation, there are a couple of bolts that hold the computer in place and a serial plug to unfasten. If she does not crank with my computer it is probably toast. Look forward to someone answering my distress call and many thanks!

Sean Phinney
86 Prussian Blue (sittin pretty)

 

Will the car not crank at all?

 

Sorry,I can't help you with the computer issue but when you get some time we could be interested in what caused your engine fire in case it's a preventable situation.

 

Hi Guys (and Gals I might add),

The car turns over fine, just no fuel and spark. I know the fuel pump works because I jumped it and got a good strong shot of gas. I replaced all the relay's that may be suspect. I double checked all ground points; every sensor is brand new. Since putting it all back together I have taken the approach of "throwing money at it" and still no start. Both harnesses were burnt to a crisp and replaced. Ruling out the computers will narrow my search drastically. I do know that the computers in our cars are easy to fry and with all that heat conducting through wires to the brain(s) it is possible that it took out the EPROM's.

As to what started the fire, I am not really sure but I strongly suspect that it started around the fuel rail. The fire destroyed most of the evidence so I will never know for sure. I have heard of several engine fires in 85 and 86's and was told by one Rennlist member that the magnesium in the intake and plenum can flake and provide fodder for a fire. This is plausible because anyone with one of these cars knows that the metal on these parts has a tendency to flake. Before the fire the paint on my intake was in bad shape and was flaking all over. Magnesium is the most electrically active compound known which is why it corrodes easy. This is probably why they went over to all aluminum intakes after 86. Once magnesium catches fire you cannot put it out. The firemen had to tear the intake plenum off by the rubber boot connections and let them burn on the side of the road.

I guess it may be good advice for any 85, 86 owner to keep their intakes and plenums free from corrosion and quickly recoat any area that is flaking. Once that paint starts flaking away, corrosion sets in rapidly leaving a white powdery substance not unlike aluminum corrosion particles. These particles are extremely volitile; add gas, heat and a stray spark and you are in for a world of hurt.

 

I have an 86.5. I would be willing to help you out as long as there is no risk of damaging my car. Any opinions out there? You don't have to pay me, but I am having a little problem with my car also. It starts right up but after warming up it idles horribly, has no pickup and puffs black smoke. I suspect my problem is the MAF. Is your MAF good? Maybe we could help each other out.

 

Hi Charles, I talked to Jim Bailey at 928 International to see if I could have the computers tested or sent out and he told me that he did not have an 85 or 86 on hand at the moment to test them. Evidently, this is the way they test them so I would assume that this is a safe method. We can wait a few days and see if someone may have something to add, I would hate to cause any further troubles to someone trying to lend a helping hand.

I bought a used MAF sensor on ebay a few months back. Since I have not started the car with the new sensor I cannot attest to its condition. I bought several other items from the seller and I spoke with him on the phone and he said it was in good working order. His 928 was totaled out in a collision and underinsured so he decided to part it out. It looks to be in excellent shape, the filament is intact and overall looks new. I could send you the MAF sensor along with the computers and we both could kill two birds with one stone. Lets wait a couple of days and see if Wally or someone else has a word to add. After that we can get in touch and work out an arrangement. Thanks for your reply.

Sean Phinney
86 Prussian Blue (sittin pretty)
Paragould, Sharkansas

 

Pull relay XVI. Check for 12 vdc on terminal 30. Check for 12 vdc on terminal 15 with the ignition switch on.

If there is no voltage on 30, check the wires attached to the positive battery terminal. If there is no power on 15, check the ignition switch. Start by reaching up and making sure that the wires are tight on the back of the switch.

It is also possible that the alarm system is set or faulty and killing the ignition by blocking voltage to 15.

 

It is possible that even if your ECU module works in another car it may not work in yours. An email Rennlister thought his GT brain was bad, plugged it into another 928 and the car ran OK. So he went crazy checking everything else ... his car would never run correctly. He swapped brains with a GTS, plugging that ECU into his car and it started right up. Our guess is his ECU was so marginal that it will probably fail soon even in the car that it would run in.

 

Sphin and Charles,

I am willing to help at no charge. I have an American 86 928S. I have been there before and it is painful. My car started running too rich. I checked as much as I could. Eventually I learned that it was a bad MAF. When I tested the MAF the output voltage was fine so I suspected it must be the LH. Partwerks rebuild the LH but it did not help. John Speake was very helpful about the MAF (visit his website). The MAF was putting out proper voltage for a short time but then it would breakdown as the electronics heated up. He rebuilt it and it works great. There is no better way to test the computer or MAF then to try it in another car. I am willing to help.

Ted

 

Ted,

My car also runs rich after warmed up. I emailed JDS Porsche several days ago but haven't recieved a reply. Is there another way to contact them? Sphin said he is not sure of the condition of his MAF. He bought it off of eBay. I need a proven MAF to make sure mine is bad. Can you help? I will still be willing to help Sphin with his computer if he needs it as long as no damage will occur to my car. (Wally?)

Sphin,

Did you try what Wally posted? Let us know what you want to do.

Charles

 

Hi Charles,
I did reply to your e-mail on 22nd June, from my info@jdsporsche.com e mail address. I sorry it seems to have gone into a "black hole" somewhere.

I always reply as quickly as possible to enquiries.

Anyway, try and get hold of a known good MAF to borrow. It seems that Ted may be able to help you out.

best regards

 

Rich said :- An email Rennlister thought his GT brain was bad, plugged it into another 928 and the car ran OK. So he went crazy checking everything else ...

Hi Rich,
Yes that was Graham Thackrah. When he came to visit me we put his GT brain on my test jig, and it did show up some faults. Just goes to show that the Bosch Hammer only tests some functions.

Same thing applies to MAFs - it only shows that the MAf has some output voltage, not whether it is correct !

 

Thanks Everyone,

I want to try Manny's procedure but I cannot make it to a microfiche reader to find the terminal numbers. I would still like to do a dry test to see if both the EZK and LH are OK. I'll try knocking on Charle's door and work out a swap for my MAF. Thanks again guys.

Sean Phinney
86 Prussian Blue (sittin pretty)

 

Charles and Sean,

I am willing to help if you want it. Email me and I will send you my name, phone number, and address. Mail me what ever you want me to test in my car and I will try it. I know the MAF is the same as on the S4, so if you can find someone local to swap with, that is also an option. Good luck.

 

Update,
Sean's computers seem fine. My car starts right up and runs very good with Sean's computers. Unfortunatly my MAF is toast. My car runs great with Sean's MAF. I have been having this car since February and I finally get to feel the Bhwaah!! I think this forum is great. Sean and I were able to troubleshoot via the WWW! John can you please try to email me from this site? Thanks