won't start

cj44 · 02-18-2007, 03:23 PM

What is the most likely cause of my '84 928s not starting after it sat for about 4 months? the batt. was disconnected ;I removed the dash pod to put in a new odo. gear ; I changed out the auto. trans. . I did'nt do anything to the engine or elect. system and it turns over just fine and fires with starting fluid and it has over a quarter tank of gas. I checked the coil wire but other than that I don't know what it could be. Please help , I'd like to drive it again.

sonett3 · 02-18-2007, 04:04 PM

Check the fuel pump fuse and if that is ok then check the fuel pump relay .

Danglerb · 02-18-2007, 04:36 PM

Do not use starting fluid, I forget exactly why on the 928, but it wasn't pretty on a VW I nearly blew the motor apart.

Gas goes stale after about 60 days if you didn't put goop in it, but that wouldn't keep it from running. Check what sonett3 said, and you don't mention what year your car is, but I think the horn relay may be the same as the fuel pump, check your chart in the owners manual or 928gt.com and swap them. If the horn still works, then the relay was good, but swapping them might clean the contacts enough that everything works. Otherwise check fuel pump I guess, mine is loud enough to easily hear it running or not. Chances are good its electrical, like most things 928.

cj44 · 02-18-2007, 06:24 PM

thanks ,I will check that out this weekend. Come to think about it I don't think I can hear the fuel pump now.
cj

Danglerb · 02-18-2007, 08:04 PM

One of the guys on another forum was talking about looking at a car that was forsale and wouldn't start. He swapped the relays and it fired right up, then he bought it. Bet it would of been interesting to see the expression on the sellers face when he did it.

12magnum · 02-19-2007, 05:03 AM

If your car started momentarily with starting fluid, then obviously you have spark, so checking the coil or other ignition parts is pointless. I agree with other people out there saying to check the fuel pump relay.

check this link below. it shows how to jumper the fuel pump relay on a later model by jumping pin 30 to pin 87. I believe your 1984 model should be similar.

http://members.rennlist.com/v1uhoh/jumping.htm

Danglerb · 02-19-2007, 12:29 PM

Fuel pump relay varies by model year, so make sure to check your chart before trying anything.

razwiers · razwiers's Garage

Not sure if you already got it started, but we have a 86 that had a similar problem.
In my case everything worked (fuel pump, ignition etc.) but did not start. I discovered after some time trying all sorts of things, that if I would take out the fuse of the fuel pump, and crank the engine, it would start, then turn off, replace fuel pump fuse, and it would start normal again,
For somee reason the non starting problem has happened twice in a years time, and this trick worked for me each time.
Not sure exactly why it worked, ( I have an idea but too long and boring)
Try it, I hope it works for you.

cj44 · 02-20-2007, 07:08 PM

Thanks everyone , all good advice. Mine is an '84. maybe that fuse trick will still work for an '84. And if that does'nt work then I'll jump the relay which I used to have to do on my '86 944's DME relay. But I don't understand why either the fuse or relay would stop working just because the battery was disconnected for a while.

Danglerb · 02-20-2007, 11:51 PM

The contacts corrode over time, not a lot, but enough that pulling the relay out and putting it back in may fix it. Maybe some other reason, but it happens enough to be commonly known. Fuel pumps go too, nothing likes to set with old gas in it, but the 928 mantra is relay relay relay.

Before you do any jumpers, make sure the fix is correct for your model year. Smoke released from the loom is pricey to put back in.

cj44 · 02-25-2007, 06:03 PM

just to update . It seems to be the relay ,I did the jump wire and it worked ,I also tried to clean the terminals on the relay and try it again but nothing happened.
So, thanks again.
cj

jsbc · 03-06-2007, 11:17 PM

I have an 85 euro lh jetronic it failed on me once then cleared ,and then a second time did the same ,third time it died completely, the fuel injection is on a relay I changed the relay for another one on the board two days later that one died to so I threw a hand full at it since then no problem . 1. If you can get a bang out of starting fluid then you must have no fuel you can jump the pump, if it runs( you can hear the racket in the back ) crack a connection on the injector line if fuel pisses out every where you have ample pressure ,if not try pinching the return line to the tank do it carefully as you can blow off some of the low pressure lines if you overdo it then try to fire it up .If your pump is not giving enough pressure or a pressure releif is stuck you wont get it to go. 2. put a meter on one of the injectors see if you can see it trigger when you crank failing that pull a bank of injectors out and crank the motor see if they fire (you will have to pull a bank as single injectors are hard to remove

cj44 · 03-08-2007, 06:50 PM

Thanks for all the tips, but I put a new relay in and it started right up and has the last 6-7 times I tried but since I can't drive it ,due to the trans still not right, I don't know 100% . but it does seem to be fixed.
Thanks