sfierle

Hello all. I have an issue with my 1983 928. Let me give you some history first.

Starting last summer, I had an occasional hard starting problem. About one out of ten starts the car would have trouble starting. It runs very well once started and has an even idle.

Noticing last fall, before I parked the car for the season, that my plug wires were in poor condition, I replaced them a couple on weeks ago. After replacing them, I drove the car a few time and all was good. I thought all was fixed.

Today I pulled the car out into the driveway for a wash (with no problems), but when I tried to start it again, nothing. The car cranked and cranked, but wouldn't start. I tried pumping the gas a little, but no good. I let the car sit for about ten minutes, tried again. No luck. Then I waited another thrity minutes, then it started right up.

I let it run for about ten or so minutes. I shut it off. I tried to start it again, and it started fine.

As I am writing this it appears that I may have flooded it, but before I touched the gas pedal it tried to start for a very long time. It appears something is on the way out, or something is getting clogged.

To me it appears to be a fuel issue, but I am no master mechanic. I have been doing some "searching" the archive, but I am not sure the issue. And the PO replaced the fuel pump before I got it (2 years ago), if it matters.

I am afraid this issue may strand me sometime soon.

Please help, sorry thiis got to be so long.

Landseer

Well, I'm no master mechanic either. But I'm wondering first about the condition of your vaccum lines, including the ones under the fender in the passenger front wheel well.

Also, Temp II sensor, which can be ohm checked.

Just some starting places, no pun intended.

sjfarbs

+1 to the "no master mechanic"

But sounds like it could be the fuel pump check valve, simple test I found on the nichols site that helped me diagnose the same issue:

http://www.nichols.nu/tip247.htm

Shawn

84' 928S
74' TR6

sfierle

That's a couple of things to check tomorrow, thanks. Any other suggestions? Being that fact that the car runs great once started, I can rule out fuel pump, fuel pump relay and dirty fuel filter. Right?!

AO

Steve, I'm not 100% certain that this applies to the 83, but on the 85+ the procedure to clear a flooded engine is to hold the gas pedal to the floor and then crank the engine. The injectors will not fire, and the cranking will give the engine a chance to clear the fuel in the cylinders. Often, it will start right up.

In addition to the items listed already, you might check the throttle switch. I'll be at the tech session on Saturday (sans 928) and can maybe help you diagnose.

Landseer

Wiggle the vac lines that enter the base of the throttle body for looseness check. They should be found sort of towards the front of the far, at the base. Then, follow them outwards to check.

cold_beer839

Could it be the Crank Position Sensor going bad?

Pull it out and see if the end has 'rounded off' some, if it has replace it because it is supposed to be flat.

Landseer

Doesn't have one until later years.

Instead, senses position via distributor. Uses a rather sensitive, prone-to-damage green wire (hall effect sensor) that leads from distributor across the front of the motor to a 14 pin connector.

May have a bell housing fixture that appears to be a CPS, but isn't.

This whole topic has been covered by the established 83/84 MY experts on the list (not me), and so there are several laundry lists you can find with a search that provide more key areas to check.

Mrmerlin

open the CE panel cover look for water on the floor, or water tell tales dripping down the CE panel supports.
if the floor is wet then it would be a great idea to disconnect the battery and pull the fuses out and also all of the relays any relay that has a corroded pin should be opend to check the contacts, also consider that from long periods of cranking the starter relay may fail due to heat, look at this relay carefully when your checking the others.
Also check the hot post for corrosion in the 14 pin connector and the hot post connection for cleanliness clean off the connections with a pink eraser and get a hot post cover from a 1988 S4 it fits like a glove if yours is missing or otherwise not installed.
For the hard start I would suggest that you add a bottle of Techrolin to the gas and drive the car, lots of short trips are better than one long drive, you could have either a leaking fuel injector, a bad check valve in the fuel pump
Get a fuse chart here www.928gt.com

sfierle

This morning I did a little looking around on the car. I checked the battery to make sure connections were tight. I found that the ground wire was a little loose. I tighten it up. Could that have been the issue? Second, I opened the fuse panel under the passenger footwell. All was bone dry and nothing looked out of order. The panel looks in good shape. Finally, I checked for loose connections under the hood. I found a sensor that felt not connected completely. I tried to start the car, it started right away first try. Waited 5 minutes, tried again, start right up. I know this has been an occasional problem, but maybe the loose ground wire was it? I will try to start the car everyday or so and see how it goes. I will also put some fuel system cleaner in the car, as suggested. I will keep my fingers crossed.

Mrmerlin

dont just start the car drive it, it needs to be done

sfierle

I drive it when I can, I get a company car that I am supposed to drive to work everyday. I plan to drive it to a tech session on Saturday.

sfierle

After a couple of good months, this problem has come up again. I plan to check grounds and battery connections for corrision again. Could this be a "green wire" issue? How about the fuel pump relay? Is a relay either good or bad, can they be on the way out and only work right occasionally? I plan to look over the car tonight or tomorrow, anything else I should check?

AO

Yes, it could be a bad FB relay.

WallyP

One "off the wall" suggestion - if the problem happens after you wash the car, check for a missing cover at the jump start terminal, and see if the short piece of clip-on edge trim is in place on the edge of the fender just above the jump start terminal.

The edge trim and cover keep soapy water (and rain) out of the electrical wiring. The 14-pin connector is especially vulnerable.