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924RACR · Posted: Tue Aug 07, 2001 12:44 am Post subject:

Kinda bummed out now - after playing a little bit with my turbo, the in-tank pump is now leaking from it's body, around the connectors. Has anybody seen this failure mode before? I tried replacing the fuel line, as I thought that might be it, but it wasn't, and I only ended up with a kinked hose which gave me fuel delivery problems. Now I can't drive it

Any recommendations on a good cheap source for this fuel pump? I'm kind of assuming the pump itself is now toast, and must be replaced, so no point swapping in the previous hose and filling it back up with gas if it's going to continue to leak fuel and I'll have to still replace the pump, emptying the tank in the process!

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

Peter · Guest

I had the same problem with my euro 924. The fuel was leaking past the electrical connector on the inline pump. I replaced the fuel pump, gasket, hoses and check valve since I was there, and as we all know, draining the gas tank is a pain.
You might be able to epoxy the connector, but I don't think it's worth the time.
-Peter A. Holiat

924 turbo · Guest

I've been lucky enough to have this problem TWICE! Once on my '80 n/a and once on the '81 turbo. In both cases, I replaced the pump, and the problem went away.

Ants · Guest

In tank pumps are not too expensive, and not too difficult to replace (heh I managed it) I actually swapped mine after a suspected problem, but it turned out to be the pump relay, so I have a spare pump if your willing to pay to get it to the states.

I imagine its probably cheaper to source one there.

Ants

924RACR · Posted: Tue Aug 07, 2001 11:54 pm Post subject:

Yes, thanks, I have checked on the prices, actually not as bad as the external pumps, and I'm picking one up at lunchtime... happy to hear that the success/recovery rate is pretty good... I hate learning a new car, that's one of the things I love about racing my 924, I know it so well there are few mysteries, but this 931 is just so different all over again...

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

Zuffen · Posted: Thu Aug 09, 2001 2:34 am Post subject:

How much was the cost of the pump Vaughn?

924RACR · Posted: Thu Aug 09, 2001 3:46 am Post subject:

Not bad at all, about $100 (racer's discount), in stock. Great distributor.

Major bummer, though... get home, it's great, swap in the pump, didn't even get the full fuel bath. Pretty happy with myself. Replace blown fuel pump fuse. Car starts, runs like crap... getting very late now, getting tired... swap in a spare high-pressure external pump, get the full fuel bath I was missing, retry... still running like crap...

To add insult to the injury I've received, I now have to go trace the wiring. I think it must be a short in the power lead to the fuel pump. The reason for this is that the fuse goes from cold (well, 95 deg F, it's hot out) to hot enough to give me a blister within 2 sec of starting the engine. There must be a short between the fuse and the pumps.

Really pissed, I wanted to drive it in to work today, after we only just got the stereo and new speakers installed... instead I'm going to waste more time sweating my bals off in this insane heat trying to get the car running all over again!

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

Zuffen · Posted: Thu Aug 09, 2001 4:29 am Post subject:

did the car run bad before the pump change?

I've never done it but you may have to purge the lines of air. Crack the fuel lines first to the dist and then to the injectors and cold start. It may be vapor locking, kinda. I think though if the units were pumping at correct pressure the system should self purge. The intank is supposed to be high flow to the outside pump which is high pressure. Do you have a fuel test gauge so You can see what pressure your running.

I've got to replace both pumps on a 80 931.

924RACR · Posted: Thu Aug 09, 2001 8:44 am Post subject:

Yeah, it died in fact... was running poorly, then stopped outright. Still sucking wind. I don't get it. I'll try cracking the lines, see if that helps... also wonder if I sprung a massive boost leak perhaps, resulting in poor running unrelated to the pumps.

To recap, the in-tank pump had to be replaced anyway because the thing was leaking fuel. The external replacement was probably unnecessary but that's what happens when you work on the same problem for 5 hrs straight after work in 95 deg heat...

As it is right now, it will start and idle, but that's all - stumbles badly and will only go up another 1000 RPM if you floor it. I have not touched mixture or timing, knowing better!

Maybe we should recap... causes could be bad fuel delivery restriction, massive boost leak, or electrical screwup, ignition related. Right? I'm very concerned by the fact that the fuel pump fuse gets so hot!?!

Let me know if you can think of anything else, or if I should just ditch the car and stick with NA's

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

924RACR · Posted: Thu Aug 09, 2001 9:15 am Post subject:

SONOFABEETCH!!! Shietze!

The only reason it was running like crud was a poor connection to the ECU... the one on the trans tunnel, with the boost line... what do you call it? The connection had come off or fallen off some time ago, I hadn't reseated it properly, and so of course it ended up coming a little loose while driving down... did I mention I live on a dirt road?

Either that or my stereo's bassive bass kicked it loose. I was under there to check it, nudged it and the accelerator just a little bit at the same time, and all of a sudden the engine clears its throat and zooms up!

I'm not used to having computers in my cars... only my test cars at work have them... and way too many... I think it's a German plot to takeover ze world... maybe I sould get rid of this and buy that TR3 I saw in a lot rusting out by Gingerman... good solid British agricultural lineage there, carbs and all, nothing with aspirations of world domination... LOL

Oh well, at least it's happy again now, and no damage done... don't tell anyone, but last time I ran an engine with a poorly connected ECU I blew it up big time... wanna piss an OEM off? Try blowing up a prototype engine! heh heh... they were kinda pissed, but hey, it was their crappy calibration that did it... it's all about failure modes... difference between quality Bosch software/hardware and crappy Delphi stuff...

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

924RACR · Posted: Thu Aug 09, 2001 12:11 pm Post subject:

One more thing, I also found many intake hoses under the hood that were loose which trying to decipher the problem... so again, not totally wasted effort...

All better now! Now I just need to get that AC working for this insanely hot Michigan summer!!!

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

Zuffen · Posted: Thu Aug 09, 2001 2:09 pm Post subject:

Well all that cussing for nothing. The ecu plug? Are you meaning the timing sensor on the bell housing?

First thing I would do is replace all the vacum lines and the rubber intake elbows including the turbo breather pipe elbow. When your in the there pop your TB off and pull the cover from the TPS and make sure the contacts are clean. Clean and tighten the overboost switch contact make sure the cold start connector is clean. replace the alternator ground strap.
And spark plugs if you haven't already.

If you pull the coil to get at things check your heater switch and maybe replace it.

You do all this and you will save yourself some headache later.

The elbows can be cut from off the wall preformed heater hose, if your lucky you can find a hose with two 90 degreee elbows. These are alot cheaper than the Porsche

_________________
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

Ants · Guest

Glad to hear you got it sorted (ish), TR3 are you mad, being from the country that built the thing give me a german car anyday. Sure their quirky and i am a bit bias here cos our weather is crap but pretty much all old british sports cars unless they were exported as soon as they were made to a hot climate will rust away on you before you can say "i love your accent, are you from london" cos its well known everybody in england lives in london. I would check the TR3 very carefully for rust, if it has been anywhere near water.

Ants

924RACR · Posted: Fri Aug 10, 2001 1:54 am Post subject:

No no, I was just joking, already did my time with a TR7...

I'll be hunting for heater hoses now... LOL... thanks for the tips Bobby...

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

Zuffen · Posted: Sat Aug 11, 2001 12:55 am Post subject:

Like a Dumb$%^ I didn't write down the Gates hose numbers when I bought mine. At 20 bucks each from Porsche they could suck my big toe. So I went to O'reillys and started scanning the hose rack and found two heater hoses that supplied the 4 elbows and a straight piece to replace the ones on the engine. I took the best old elbow and replaced the upper vent elbow on the turbo.

I think it cost like 14 bucks.

Also I learned that using the factory replacement rubber/fabric braided vacuum hose didn't last as long as using off the shelf high quality vaccum hose. The German stuff split on the ends wihtin 2 years. I might have gotten a bad or old roll but makes you cautious.

_________________
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