Avar928

This is for an '86 928S 32V Auto with S3000 chips and X-pipe.

So my car will crank and crank but won't fire if on level ground. I pushed it out of my garage and onto an incline and she fired on first crank but quickly died. If I try it again right after, no fire. Let her sit and she'll fire and die. I pulled the computers and checked for breaks in the shoulder on the EZH at the chips and found no breaks or anything to solder (under the suggestion that replacement of the stock chips improperly can cause a break and lead to intermittent non-firing).

Last time she ran I drove about 120 miles round trip. About 60 miles in the fuel pump was buzzing so loud I could hear it. However, when I shut her down and ran her again there was no sound. Fuel pump is used, 10+ years replaced ago from 928Intl + fuel filter. Not sure what's wrong. I was about to jumper the fuel pump but when she fired when on the incline it threw me off on my diagnostic assumptions.

Work Completed:

- Recent TB/WP with all new gears and timing reset
- Porken Tensioner + Klamp Upgrade
- Intake refreshed 3 years ago
- New spark plugs
- New ignition wires
- New rotors and distributors
- New CPS
- New TPS wire harness
- New Temp II
- New M-A302 Ford Injectors + o-rings
- New ISV
- MAF rebuilt
- New '87 FPR + New Rear Damper

Avar928

Jumpered the pump and I can hear it run from inside the cabin with the passenger door open (fuel pump cover off).

Going to pull my plugs and check them out.

James Bailey

Hmm maybe just maybe your O2 sensor wire is grounding out on the x pipe but moves away when on the incline.....

Bjbpe

Not sure that I can help but I was having fuel pump issues a short time back. If I zapped some either directly into the air filter the engine would fire then die. After searching hear and there one of the good folks here suggested I check the fuse. I pulled the fuse and it looked fine. Just to be sure, I ran a continuity test on the fuse - it was ok. Put the fuse back in and the car fired up where it wouldn't before. I suspect there was contact resistance, just enough to give the fuel pump fits. Cleaned the fuse and the contacts - no more problems. Hope this helps.

rnixon

How full is the fuel tank?

Mongo

I still think it may be the fuel pump. Sometimes, function is intermittent before failure. The loud buzzing is also a clear sign that it's on its way out.

Avar928

A little under 1/4th. I added another 1.5 gal thinking my meter was wonky and I was on empty. I did check the fuse and relay and they looked fine. Switched relays with the horn and still the same. Jumpered the pump and started her and the same thing, cranks and fires and dies. Won't fire again until she sits. I'll replace the fuse and check the O2 wiring also.

Passenger side plugs look normal. Pulling driver side now.

Avar928

That's my thought too Mongo because it was never that loud before the run. I just want to clear anything else out before I drop almost $300 on a new pump and filter.

Mongo

I had a friend with an old VW Fox wagon that would do the same thing. In fact everytime he drove up an incline, the car would die. We go down the same hill, and the car runs completely fine! A week later, no buzzing, no start and it became a tree topper for his Christmas tree in the garage.

Avar928

What makes me also lean towards the fuel pump is that she'll never fire, not even once, on level ground but on the incline will give me at least one every 15mins or so. If it were spark or the computers I'd be guessing the no fire would be straight across the board.

What I don't get is why it'll fire and die then won't fire and die again and I have to wait. That throws my assumptions off like spark is an issue (i.e. the engine is flooding because spark is weak).

Avar928

Passenger side spark plugs - Left to Right is 8 > 5



Driver side spark plugs - Left to Right is 1 > 4



Driver side looks to be a problem. If I researched right it's low compression affecting cylinders 1, 2 and 3. I've run BG44K three times through her within the last 3 years. No oil in the coolant, no coolant in the oil. Not sure what else to think of it especially since 2 and 3 are darking on half the plug and that side is running rich.

SteveG

I re read this, I'm still not sure . . . . when you say incline, is the engine higher than the rear?

Either way, you have two solid indicators of weak or intermittent fp behavior. Have you put a pressure gauge on the rail?

The driver side plugs are troublesome. Oil is known to collect in the intake. I wonder if blowby oil is pooling in the intake, perhaps on only one side.

Mongo

Left bank running lean, right bank running rich... hmm. The scary part is those plugs on the right side look a little too clean for their own good. Totally unrelated but a good piece of mind - Have you done a compression test on the motor?

Bjbpe

The noisy fuel pump is another likelihood. Could be cavitation at the inlet to the pump or just time to bite the bullet. I replaced mine a couple years ago for the same symptom, then ran into the "dirty" contact at the fuse two months ago.

Mrmerlin

I would suggest to reinstall the old chipset