Car wont start after almsot year of sitting

959Komfort · 02-18-2008, 12:07 PM

And the recent clutch job. The tank was almost empty when I parked it. Just gave it three gallons and tried to jump start. It turns over some then nothing. Could it be that I mixed up the two speed sensors up front? And how do I know which seonsor goes into which hole?

hpservertech · 02-18-2008, 12:10 PM

Does the tach bounch when cranking?

959Komfort · 02-18-2008, 12:13 PM

Yes it does. Guessing switched up the seonsors?

Razorback1980 · Razorback1980's Garage

If you are unsure, then mark them and then switch them. IF it starts, you had them backward. If not then unswitch them.

jmd_forest · 02-18-2008, 12:58 PM

It is not unusual for these cars to refuse to start after a long sit. Pull the air cleaner off and try a squirt of starting fluid in the intake. If it starts, you have a fuel problem. If not, likely it's an electrical problem.

One trick I've learned is that the injectors tend to "bind up" after sitting a long while. Try holding a BIG screwdriver like a pool que and tapping gently but firmly on each injector where it meets the intake. This often loosens the "bound up" injectors and allows the injectors to pass fuel.

jmd_forest

959Komfort · 02-18-2008, 03:34 PM

Is it possible that my fuel pump went out? I just noticed that I dont hear any buzzing from it when I turn key over. Does a 944 fuel pump even make any noise from the interior? I ahvent had my car running for such a long time that I dont even remember.

hpservertech · 02-18-2008, 03:38 PM

Try to jumper it and see if you hear it run. Check out www.clarks-garage.com for the steps.

959Komfort · 02-20-2008, 12:33 PM

I might do that but first I want to know if you could normally hear the fuel pump for inside the car.

Razorback1980 · Razorback1980's Garage

You should be able to hear it with the door open.

Dean924s · Dean924s's Garage

You do realise that you don't have to swap the sensors you just switch the plugs around.

Is the tack bouncing when you crank it?

959Komfort · 02-20-2008, 11:28 PM

The tac is no longer bouncing AND my car started with starter fluid. Now time to figure out whether its fuel pump or injectors that are screwed up.

jmd_forest · 02-21-2008, 06:09 AM

After using the key to crank over the engine a few times, crack the nut at the front of the fuel rail. After a few turns of the nut the fuel should spray out under high pressure. If so, the fuel pump is probably OK. If not, you need more diagnosis.

Possible causes of lack of fuel pressure:
1) Bad fuel pump
2) Bad DME relay. The DME relay actually has 2 internal relays, one for the DME, one for the fuel pump. You can pry off the cover of the relay and actually watch the relays operate when someone else turns the ignition key.
3) Bad fuel pump fuse
4) Bad fuel pressure regulator

If you've got fuel pressure, try the trick I suggested in my previous post using the BIG screwdriver and tapping the injectors. I know it sounds too good to be true (a FREE fix to a vexing Porsche problem?????) but it actually works, if binding injectors is your problem; and from the thread, it seems like a reasonable possibility.

If the tapping does work, get a fresh 1/2 tank of gas and drop in 2 containers of the best fuel injector cleaner you can find.

jmd_forest

959Komfort · 02-21-2008, 11:26 AM

Thanks, jmd_forest.

Im gonna look at all those things and see if I could figure this out.

thekidd · 02-21-2008, 01:03 PM

yes you should be able to hear the fuel pump "humming" from the inside, maybee with the door shut. It might be a good thing to change the T-belt, distributor cap, plugs and wires, and put premium fuel in the tank beacuse the old gas may have gunk up over time. Good Luck.

959Komfort · 02-21-2008, 03:29 PM

The pump is dead silent even when I was right next to it while someone turned the key. So Im sure I found my problem.

hpservertech · 02-21-2008, 03:57 PM

Check the fuse first. Could be that simple.

Razorback1980 · Razorback1980's Garage

Just turning the key on will not make the fuel pump run. For the fuel pump to run, the engine must be turning. This was a safety device to keep the fuel pump from dumping your gas tank on the ground if you crashed your car. If you are turning the key to start, and you don't hear the fuel pump, then you have a problem. Just turn the engine over a few seconds and then crack the nut on the end of the fuel rail. If gas spews out, then your fuel pump is running....if not, then start looking at why.

Lapponia · 02-22-2008, 03:38 AM

I agree with Razorback. Engine must turn either by cranking or running normally. Pin 20
at DME then gets a fixed chassi ground (- 12 volt) thereby activating the second half of the DME relay (the first half of DME relay should first be activated by the ignition key). Then current gets to DME (current supply), injectors and fuel pump. Engine would start.
But I´ve seen so many issues around this matter and none of you guys have said nothing abuot that big nine pole wire connector at the firewall. This one connector is so important to many functions around DME for the injectors, fuel pump, supplying voltage/current to DME etc.
And guess if there is corrosion in there. Yes there is and more likely than in any other place.
I did break that connection when I purchased my my 944/84 a year ago. The car ran but the pins (male/female) did not look good. So I cleaned them with fine sandpaper, ´lubricated´the whole thing with WD40 and put the connecor halves together again. Repeated this 4 - 5 times to be shure of good and lasting contact here. I just want to mention this as it could be the cause of many electrical problems.
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Lapponia