ivangene

so I know I should have a spare DME relay in the car but I didnt...

to start off last week getting fuel it died for the first time ever (right after I filled it, then turned and didnt start, then started)

the next day it "sputtered on me

the next day I had the "ALT" charge light come on for unknow reason...

I asked my guys at the shop what to do and they suggested I drive it, but I forgot to grab a spade relay - so tonight after work, cranck, nothing...

Turns over fine, lights fine, oil presure up, wont kick, thinking relay...

Got a ride home from a co-worker and stopped off to get a DME - heading up to "fix" it in the rain and drive it home or tow it ....

one of those days when I could hear the board saying "you should always have a spare relay in the glove box

let you know when she is home - hoping this solves it

Ed Hughes

What else can you ask for? It was trying to tell you! Now you need to buy another spare. If you change the old one out proactively, you can use it for the spare.

Actually, fingers crossed, but its a good bet.

w00tPORSCHE

Ed, ...jeez of all people U ... shame on U.. On a sidenote, now I know what I want for Christmas. Here's to a speedy recovery for your '86 coupe.

rusnak

Relays stick, contacts get dirty. You might've gotten lucky by tapping on it while cranking. We do have a number of "no start" threads that also begin with cleaning the battery contacts and making sure you are getting 12v at the dme harness side.

ivangene

well, LONG night... went up with the new part and nothing - wouldnt go - back home got the truck and a tow strap...

2 major issues, its raining like hell, my wife has never drive my truck and my wife has never driven on the freeway, gets lost in the daytime and barely able to get 4 miles from home without getting lost (my car was 18 miles away) - yea two issues -

with the cell phone on speaker, my kids in the truck relaying the messages about how to drive, where to drive and comforting words we cruised on home without any trouble - BRAVO HUNNY !!

I thought about dropping it off right at the shop but 2 things (this time for real only 2 things) were on my mind. Fixing it myself (saving money) and saving money since it is needed in a few days for xmas, I might not fix it before then if its something more than a simple relay or contact.

I guess the diagnosis begins tomorrow/friday, a little sad, a little proud of my wife and a little worried, but I am sure things will work out - I already miss driving it tomorrow -

OH - I checked, it has spark so must be fuel - suggestiong on where to start.....? Counting on the tribe

rusnak

long night myself, but this is totally work related.

Have you checked the fuel tank screen? J/k.

You might jumper the dme socket as Bentley instructs so you can check fuel pressure and delivery. Verify voltage w a multimeter at the icv and ideally at one of the injector connections.

Iirc, steve wong described a section of the dme, that if it cracked a solder joint, you would lose fuel. It's one of the small boards at a right angle to the two main boards.

Ed Hughes

Check crank sensors as part of the diagnostics. Iceman posted sone good info there this past summer. Bentley has a great trouble shoot section, step by step.

ivangene

I replace the CHT sensor a few weeks back so lets hope I didnt "cause" the crank sensor to fail by doing something to it in the process of fixing something that wasnt broke - thanks, I will check it out.

I think the first step is to check the fuel pump and on back to the fuel rail - then dig deeper if needed

theiceman

Hey Guys

Just passing through and noticed this .

My work last year was on the CHT. That is definitely not the issue here . If The CHt had been bad you could have jumpered it with the paperclip you had taped to your DME and been on your way .. oh wait .. and besides .. if the CHT had been bad it would have fired up immediately when you went back with the engine cold and would have struggled after warming up.

The fact you have spark would lead me to believe the reference and crank sensor are fine but Loren is the real expert on that stuff. In my other cars the DME needs to see the crank and hall sensor synchronized to fire. I have seen the hall efect sensor intermitently fail and allow the car some sort of limp mode after it has started. when it is in fail mode however it will never start. Typical symptom is it will be very difficult to start .. and not fire at all. but if it does start it will seam to run fine.
If you have spark but it spluters and dies I would agree with your fuel pressure asesment. make sure you have fuel pressure to the injectors ..and of course it is not deisel

I have no idea how you would trouble shoot a MAF on these cars short of swapping so I will let someone more knowledable on DME chime in for this ..

Ed Hughes

I see the diff, ice. Didn't fully digest Ed's original symptoms. But, a thorough going over is in order.

ivangene

loaded with info, tools and parts, heading home now - should be done in an hour

(I wish!)

ivangene

OK - jumped the fuel pump and either is SUPER quiet, or not working....

going to pull her out and bench test her -

edit, pulled cover, checked line voltage at pump, its good - so pump bad, calling shop -


parts tomorrow - will install asap naturally - kinda fun finding a problem with that Bently, good pics and descriptions, very easy to follow

dshepp806

It is quite fun, for me.

"The waiting is the hardest part"...........


Doyle

whalebird

Gently clamp the fuel line and go for it. One thing I learned was to tie a twisted shop rag around each wrist to catch fuel dribble down your arms. Counter each bajo fitting with a wrench. Don't let the rubber FP mounts take the force of removing the fittings.

ivangene

Thanks WB - got it.... HOld on Doyle I am working as fast as I can, here's another beer