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"New" car issues
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Tue Sep 03, 2002 10:24 pm    Post subject: Reply with quote

Doing well with the "new" car - an 81 931 from Bobby's yard by way of Des Moines... picked it up Saturday, had it home Sunday evening, running Monday morning, and cleaned off and waxed (looks so much better) by Monday evening.

In the midst of countless electrical gremlins, it won't stay running... think it's actually a fuel starvation problem, actually, not the control pressure regulator... length of run time depends on how high I rev it; rev it high, it runs great but dies quickly, let it idle, and it'll run longer before stumbling and croaking.

I think it's two possible issues; I think when replacing the main fuel pump I forgot to reconnect the internal pump (electrically), and I think the feed hose may be a bit too kinked to allow the main pump to draw well.

Runs surprisingly well on the varnish that's in the tank. It's clean, but smells very bad.

Car's an '81, was parked in 91. Somebody didn't like this car! Trying to decide whether to start racing it in PCA I Stock class, or to go straight to GT with the GTR bodywork. Have to look over the rules first!

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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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Ants  
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PostPosted: Wed Sep 04, 2002 12:30 am    Post subject: Reply with quote

Dont forget the fuel pump relay aswell, had a similar prob myself, changed the external pump, and it turned out to be the relay that would only allow it fun for a short time.

Ants
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Wed Sep 04, 2002 12:50 am    Post subject: Reply with quote

Quite true! It doesn't have a relay yet. I have to order one - just using a jumper for now.

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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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924martinirossi  
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PostPosted: Wed Sep 04, 2002 4:01 am    Post subject: Reply with quote

Having fuel problems myself. I found alot of "foam/sponge material in bottom of tank. I also replaced my intank pump. When I push the air meter plate there is no sound of injectors opening. Both of my fuel pump relays are good. Check brown wire to ground on the fuel pump relay. I connected mine to a good ground. I connected 12vdc to pin 30 (fuel relay) and I get 10.75vdc at the pump. I then connected 12vdc to additional fuse #2 and I get 11.05vdc at the pump. My intank pump draws .22Amps at 12.50vdc as measured on a digital powersupply (pump removed from car).
I'm checking the wiring from relay to fuse block today and jumpering straight from battery to pump.

Will let you know what I find today.

Michael
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924martinirossi  
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PostPosted: Wed Sep 04, 2002 4:01 am    Post subject: Reply with quote

Having fuel problems myself. I found alot of "foam/sponge material in bottom of tank. I also replaced my intank pump. When I push the air meter plate there is no sound of injectors opening. Both of my fuel pump relays are good. Check brown wire to ground on the fuel pump relay. I connected mine to a good ground. I connected 12vdc to pin 30 (fuel relay) and I get 10.75vdc at the pump. I then connected 12vdc to additional fuse #2 and I get 11.05vdc at the pump. My intank pump draws .22Amps at 12.50vdc as measured on a digital powersupply (pump removed from car).
I'm checking the wiring from relay to fuse block today and jumpering straight from battery to pump.

Will let you know what I find today.

Michael
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Wed Sep 04, 2002 8:23 am    Post subject: Reply with quote

I did confirm that the intank pump was still connected, but the external is straining like an old man on the pot! I can get it to run a little longer with the hose routing fixed, but it still dies. The tank is now draining (varnish to be fuel for the Tow Beast) preparatory to removal and inspection (and, hopefully, cleaning) of the in-tank pump. I want this biznatch to run!!!

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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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924martinirossi  
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PostPosted: Wed Sep 04, 2002 11:54 am    Post subject: Reply with quote

Here's what I found:
Pump wired direct to battery (12.90vdc)pulls 1.60 Amps with internal pump disconnected. Also injectors squirt.

Voltage at wire without pump connected 12.84vdc (measured at pump end).

Thru normal wiring voltage at pump (running) was 11.80, voltage at pin 30 (pump relay)was 12.60.

I found is a black/green wire that connects to fuse 2 of the additional fuse board and goes to a butt connector. This plastic connector was very corroded. A simple cut and new connectors solved the problem. This wire and connector is in the bundle above the fuse block.

Michael



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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Wed Sep 04, 2002 12:34 pm    Post subject: Reply with quote

Had the same corroded connector as above - but it was hot from high resistance.

Anywho, pump is pulling fine from clean gas can. Injectors now spray using Brakleen as power. However, #4 is not even getting fuel, and the rest won't spray when hooked to the fuel lines, pump running, airflow meter depressed. Bummer. Have to swap a few parts with the other car, the 82, see if the injectors from teh 81 will spray on the 82 or vice versa. Hope a set of injectors (in addition to pumps, pump relay, and accumulator - yes, that's leaking too) and a soaking in acetone of the FI distributor will solve the problem, along with a cleaning of the gas tank (haven't figured out how I'm going to accomplish that one yet)... Then it might run.

Real tired...

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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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Zuffen  



Joined: 31 Jul 2001
Posts: 1426
Location: Owasso, Oklahoma 74055

PostPosted: Thu Sep 05, 2002 1:00 am    Post subject: Reply with quote

Find a fuel line to fit the injector and run some diesal injector cleaner into the line and use compressed air to fire the injector. The brake clean is too thin and won't give you an accurate injector response

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Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951
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Zuffen  



Joined: 31 Jul 2001
Posts: 1426
Location: Owasso, Oklahoma 74055

PostPosted: Thu Sep 05, 2002 1:02 am    Post subject: Reply with quote

Your not getting fuel through the dist.

Are you getting fuel to the dist?

Maybe the filters are clogged

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Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Thu Sep 05, 2002 1:41 am    Post subject: Reply with quote

Yeah, I'm getting fuel to the dizzy - it's coming out at the other 3 spots (outlet lines to the fuel injectors), just not the line for #4. I'll have to figger a way to push some fuel through, but do also still have the other car which runs fine to cross-check with.

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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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924martinirossi  
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PostPosted: Thu Sep 05, 2002 12:45 pm    Post subject: Reply with quote

Run a 10gauge wire directly to the positive of the intank pump (disconnect intank connector and clip on) then push down on the meter plate and listen for injectors. My car done the exact same thing untill I wired directly to the battery. At anything less than about 11.8vdc pump will not spin fast enough to build the 40psi or so to open the injectors.

Michael
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Thu Sep 05, 2002 12:52 pm    Post subject: Reply with quote

Thanks, you had it - after cleaning all contacts, including a scouring of the fusebox, the car will run (though not well). I think it was the ground, which is located in the trunk by the left taillights, that was the worst. The injectors will now spray when the metering plate is pushed.

I still think I have to soak the FI distributor, as well as the pump, in acetone for cleaning. I also still have to clean the gas tank and many other things before it'll be a toy.

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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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924martinirossi  
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PostPosted: Thu Sep 05, 2002 2:31 pm    Post subject: Reply with quote

If all the injectors are firing I would just dump some Techron down the tank to clean the injectors. Start looking for vacuum leaks. Check rubber elbows and the 3-4mm vacuum lines that run across the top of the intake.

I found a bad elbow, the rubber gasket on the intake and all vacuum lines, plus, the air intake rubber boot was not seated properly.

Michael
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Thu Sep 05, 2002 10:44 pm    Post subject: Reply with quote

Yeah, only the tank's still dry - need to clean out that junk yet. Also lent out the fuel pump to a racer (maniyak) trying to get out this weekend. However I still need to see if #4 is getting fuel (which I doubt). Just have to face it and commence soaking in acetone. Yes, I do expect plenty of vacuum leaks; have still to find a source other than dealer to get those large vacuum boots from.

But at least it'll stumble though an idle!

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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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View user's profile Send private message Send e-mail Visit poster's website
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