Desolation

Troubleshooting mode - my '81 stumbled, stumbled, then croaked on the side of the road. It won't start, and I'd like to avoid the tow job if I can (it's a half-mile from my house).

I've done a lot of stuff lately - the whole TB/WP thing, all the accessory belts, and a few hoses. It started and ran well the last two days, then today it started running rough and kaput. I just replaced the battery - the car had been sitting for a year with an older battery - and no change. Still whirrs at a high pitch, but no catch or start. It's hot here, and the engine had not really cooled. All the wires seem kosher, but there could be something loose.

Any ideas - experiences, etc. the group could share would be great - I couldn't have done the TB/WP without the assistance of the rennlist gurus.

Steve

'81 5-Sp, currently hugging the shoulder of Vet's Highway in Bloomington

Bill Ball

Steve:

Until proven otherwise it is relay, relay, relay (Jim Bailey). So jump pins 30 to 87 in the fuel pump relay socket (XVII) - the fuel pump will run all the time. If it doesn't, check the fuel pump fuse (25). If that doesn't do it, jump the fuel injection relay socket (XVI).

Also, there is the infamous GREEN wire to the ignition module. Pull a spark plug and verify that you have spark. If so, to verify that the problem is fuel, you can put a quick squirt of starter fluid down the intalke. If the car sputter to life, you know to keep looking at fuel delivery (bad fuel pump, clogged filter, etc.).

Now, the fact that it started to run roughly for the past few days argues against a relay (they are more definite and sudden - the car either runs fine or it doesn't run). So, look for component fauilure, like fuel pump.

That will give you some things to do. Basically, you need to establish if it is spark or fuel that is failing. Then go through whichever system. We can get more specific after you have done some of the above.

TRUESCOTSMAN

I DONT LIKE THE SOUND OF WHIR WHIR . does it sound like it is turning over properly? I would hate to think the tb has broken. WHIR whir suggests it is turning over without compression, ie valves not moving or is the sound of your car turning over just being lost in the translation.

Bill Ball

Yeah, I wondered about that at first...should have asked. I interpreted what Steve wrote as the engine turning over rapidly but not firing up, and not as a bad starter bendix drive or a broken TB. Good question.

Dangerm

I've had some starting problems when cold - same kind of thing with the engine turning over but no catch. Has become really bad now - turns out that the coil is stuffed, so maybe that is also your problem?

Desolation

Well, I got it off the side of the road (flatbed 1/2 mile for a mere $80). Tried starting fluid, jumping the fuel pump relay and inspected the green wire along with other obvious connections - no dice. It seemed to gurgle a bit with the starting fluid, but no catch. My wife's trying to move some kidney stones today, and the kids and I are debating the merits of Dante vs. the Book of Revelations to use when describing our week, so it may be a while before I can get back to troubleshooting.

I doubt it's the TB - brand new, and seemed fine as I tested it over two days. I'm inclined toward the fuel filter/pump system, as a 1/4 tank sat in it for almost a year and due to the way it went down: runs fine on Sunday, then Monday night, and then hesitates and chugs over a few miles the next morning before cutting out altogether. I had also left it parked in the driveway the previous night (a significant incline, after a year on the flat garage floor). I'll post updates as I go.

And to all who have replied so far - a big thanks.

A few other notes for the group - I also did the ball cup shifter thing that the only P-car mechanic in town screwed up for me last summer. I used a big wrench as a pry bar to pop it off (tricky angles) and some rope and a dab of radiator hose grease to get it back on. Sketchy stuff, as there's no room to work with. I removed the big heat shield, and the little one on the driver's side, but left everything else attached. I used some 9mm climbing accessory rope, doubled it and then twisted with a small breaker bar to bring on the pressure - it took quite a while to coax it back on with my little girly arms, but I got that satisifying "pop" when it wnet back on and I can now shift into 2 or 4 without smashing my knuckles into the radio. I had to turn the ball cup out 4 full revolutions to get a good alignment. An ugly job, but not too bad for a newby. And forget trying to get that lock nut tight - any wrench stubby enough to fit in there probably wouldn't offer enough purchase to add much torque. I don't think the lock nut does much, as the cup has to be off in order for the lock nut to serve any real purpose.

On the TB/WP - my best advice, after the first time I've done it, is to make sure you have lots of time (er, honey, I'm going to need the garage for a month or so ...) and lots of penetrating oil. I soaked those WP bolts for a couple days and they came out like butter. The crankshaft nut too - a two foot breaker bar, a couple days of penetrating oil, and it came off after the fifth tug with my skinny little girly arms. When I went to put stuff back together, I cut one of the old raditor hoses in half to "pre-fill" the block and radiator with fluid. A little messy, but it made the burping process go faster.

I also used one of those one-man bleeder hoses for the clutch slave and all four brakes. Worked really well, and a lot cheaper than a mity-vac.

Bill Ball

If it didn't fire up on starter fluid, then you need to check spark - pull a plug and ground against the head and see if there is good spark. There are other ways but that will do for a quick check.

Garth S

I'd still go back to the "whirrs at a high pitch": none of the 928 I've twisted a key on do this - there is a very clear starter engagement, and you can feel and hear the engine turn over - and to confirm, all the v-belts in front turn in unison with the starter. As you have a 5-sp, bump the starter with the car in first - allowing room to avoid driving through the garage wall
If the starter is turning the engine, move on to checking fuel & spark.

zoltan944

i know you don't think its your timng belt, but you better check it.
this is what happened to me before:
did t-belt/WP, started car perfect ran for 5 minutes, shut it off. started again made funny noise, turned it off, now it doesn't start, has fuel and spark. That funny noise was your valves bending.
turns out ive done every troubleshooting thing ever! i am now pulling the head as we speak. it turned out that the tensioner went fubar so at first sart up the car was great when it stoped it lost tension from belt speed and jumped teeth, so at resart.....wawawa
take a peak at the sig!
I really do hope this isn't your case, but just kinda sounds EXACTLY like mine that all!

Nasty 928

My car will not start after I let it run for 5+ mins. I have changed the check valve on fuel pump, new fuel filter, swaped fuel injectors(used ones with used ones), rebuilt my distributor( I like to play with electric motors and thingys) , made some accel 8.8mm plug wires, ngk R plugs, msd blaster 3 coil, k&n filter, new tb, NEW green wire, new cap and rotor, and still same old SH*T. It is also worth note-ing that I have only put about 10-20miles in the last 3 years.(the shark sits in garage) I have drained the fuel tank and replaced with fresh fuel+marvel oil 2 times. Like I said before, it fires 1st try everytime....when the block is cool, if I try to start when warm, nothing.

I have searched the net for similar situations, only thing I have is a part called the aux air regulator?? or the warm-up- regulator. Some one told me that the car's 9th injector(COLD START VALVE) is what starts the car, and that this is what I get for not driving it. He said parking early 928s is the kiss of death for them.

If you come up with anything let me know, I am all ears.

Jack Riffle

Make yourself a 3-way jumper wire. Remove relay XV1. Insert one end of the 3-way jumper into the #30 terminal in the relay board and the other 2 ends into the 2 #87 terminals in the relay board. Then try and start the car. If the car fires on the cold start injector but no other time, then it sounds like the AFC relay is shot. This quick check will tell you that. The WSM will not show 2 #87 terminals, but trust me, there are 2. If the car starts and runs with the jumper in place, order a new relay. Good luck.

Desolation

OK -- First round of troubleshooting in the garage (MUCH better than the side of a busy highway with a cop looking over my shoulder). Results - the T-Belt looks fine (it bloody well better), high pitched whirring sounds more like the normal starter sounds (perhaps a new accessory belt has changed the note?) and evrything turns as expected, and then checked for spark (yep, plenty of spark). On to the fuel system - pulled the cover and found a little dripping gas from the check valve area of the pump; had the wife turn the key repeatedly to send the pump some juice, and it only buzzes about once in every four or five attempts. Could be the relay or the pump - I ran out of time and daylight for the jumper exercise.

Best guess at this point - the pump may have given up the ghost (or it's very close). Or the relay. Or both (what the hell). Anybody got a similar story to share? I'll update as I go along.

Bill Ball

You can pull the fuel pump relay and jump the socket, pin 30 to 87 to test this. The pump should run as long as the jumper is in.

Mrmerlin

It would be nice to know if and what pressure you have in the fuel system after installing the jumper

Andre Roodnat

On several occasions I here people say how they changed out all the wiring, rotorcaps, and what else more. I think the key is elementary first. If stranded by no apparent reason, don’t try to restart, but do a check for the timing belt first. Just pop the air intake hoses of the timing belt covers and look into both peep holes if it’s intact and if it seems to be tensioned. That’s not bullet-proof of course, but it’s a 1 minute job and gives some reassurance before trying to start the car again.

For combustion you need a combustible fuel mixture (fuel, timing, compression and oxygen) and a combustion temperature (spark).
Before tearing everything apart, check fuel flow. It’s easiest to check the fuse first, then exchange the relay. If both are ok, it’s pretty easy to disconnect the fuel line at the injector rail. You can even do that when stranded with the on board tool-set. Start the car and look if there is a good and strong fuel flow. But be extra careful about it! Do not let the fuel gush over a hot engine! Always carry some rags with you in the car. Also be careful that you don't drop the loose ball in the connection, which acts like a check-valve.
By checking the fuel flow at the front, you eliminated: electrics, intank pump (if present), fuel pump, check valve and blockage at the lines or filter etc. Listening for a buzz at the bumper can give a hint when there’s no noise, but a buzz is no guarantee for a proper working pump (ask me how I know).
If all is OK then check for a spark. Again, be extra careful, as the powerful spark has enough load to potentially kill you. Get a spark plug out, and hold it with a rag against ground. Have someone start the car and check for a strong blue spark. Also check a spark-plug from the other bank as it’s a dual system. Look at the sticker for the sequence for this. Probably not a good idea to do this in rain or on a moistly surface.

If all has checked ok, there are tons of other stuff that can be bad like the brain(s), injectors etc., but in many cases related to the above.
By the way, I’m not trying to be a mr. know-it-all as I’m not an expert on this. I had to learn it the hard way too.

In your case Steve, it seems as indeed the pump is out. I had to change a bad pump twice in the last 5 years. Check the fuel-flow as written above. If any doubt, there is a write up in the manual were you have to measure the amount of fuel pumped after bridging the fuel relay for 1 minute. You can remove the fuel-pump cover by removing the 2 nuts. It worked best for me to entirely remove the pump, filter and linings by loosening the linings at 2 points and the pumps bracket. This way you can disassemble and assemble the linings in a bench-vice, which provides you the necessary grip. Before removing the assembly though, you have to clamp off the rubber fuel line. I just sawed 2 brackets and drilled holes on the edges of each bracket. With 2 screws and nuts, you can turn it into a clamp by sticking the fuel line in between and tighten the bolts. But I’m sure there a plenty of tools for this too.
The pump comes with a new check-valve (for my ’89 anyway). Always renew your filter when renewing the pump! This ensures that in a case of seizure of the old pump by junk from the fuel/filter, it doesn’t ruin your new pump. It says so on the fuel pump box as well.

On both occasions when I changed my pumps, it was a b!tch to have the connections drip free. I just had to tighten until it was. Felt pretty scary though to tighten like that with the big wrenches though. Always use two wrenches! One too tighten/loosen, one to hold the other part into place. This way it doesn’t strain the linings. They twist pretty easily.

Good luck!

All the above is based on my experience with my '89. Other cars might vary.