creaseuk

I've inherited the problem of starting my elderly Mother-In-Laws '89 944. Its in beautiful condition having been stored in a garage for the past 10 years. I fitted a new battery to it hoping it would start, alas no... So, I tried spaying starting fluid in the inlet manifold, that makes the car fire but not start.. Then I found an old fuel pump in the passenger well (Mom has dementia can't tell me anything that happened less than 40 years ago) indicating that it may have been recently changed. So, I checked the fuel pressure at the fuel rail, nothing, only the tiniest of drops. So, I put two gallons of fuel in the tank. It still won't start or push fuel through the rail.. So, I changed the fuel sender fuse & the fuel pump relay. It still won't start. Now I'm at a loss ... Here's the other thing.. Its a 1989 model so the Haynes manual is useless (you're chuckling now, I can tell) I have no idea where the fuel pump is.. I've looked under the car, the fuel filter is brand new & there's a new cable tie under the fuel tank, But I can't find the pump (there's no sound to guide me there either). I also don't have the small key to unlock the wheel nuts, do you have any suggestions on how to remove the locking lugnut without a key?? I'm really frustrated with this !!

Rogue_Ant

Check out:

http://www.clarks-garage.com/shop-ma...ure-index4.htm

It is one of the best resources for troubleshooting/repair on our cars.

With the car starting on starter fluid, and no fuel in the rail, it sounds like the the pump is the issue.

For testing you can the fuel pump relay (more commonly known as the DME relay). This will let you know if the pump is at least working or not.

creaseuk

Thanks for the speedy response ..

For testing you can the fuel pump relay (more commonly known as the DME relay). This will let you know if the pump is at least working or not.

I think there is a word missing from this sentence ... I have fitted a new DME Relay .

Rogue_Ant

Ha - yep, I meant to say that you can jumper the DME relay. This will run the fuel pump continuously (until you remove the jumper).
See this page:

http://www.clarks-garage.com/shop-manual/fuel-05.htm

creaseuk

Wow - Thanks - I'm going to try that..
Do I need to remove the wheel to find the fuel pump?
The pictures in the manual look great but don't really show where the pump is..
I'm really really hoping that when I find it - the connector has fallen off.
I'm desperate not to look a chump..

Rogue_Ant

There a fuel pump replacement guide on that website as well...
Its been a while since I've done one, so I don't remember if the wheel needs to come off or not.

creaseuk

It Doesn't really say - but from the pictures I can see the wheel. Then i'm sure the pictures were taken when the car was on a lift, I only have the benefit of jack stands!

mel_t_vin

It's been a few years, but, I've done two 944/951 fuel pumps, in the driveway, on jackstands, without removing either rear wheel. Takes less than an hour, from start to finish, with time for a bite and a beverage. To limit spillage, I'd suggest doing the job with as little gas in the tank as possible.

Have a set of hose pliers [or a helper] on hand to clamp the line from the tank to the pump. Raise rear of vehicle [ramps would probably work]. Disconnect battery. Remove plastic cover on passenger side of tank. Disconnect electrical connections at pump. Loosen nut of pump-to-filter line at pump. Apply aforementioned hose pliers or able-bodied assistant to tank-to-pump line. Disconnect tank-to-pump line at pump [hose clamp?]. Remove previously loosened fitting of pump-to-filter line. Remove pump. Installation is reverse of removal.

Since you mentioned the car has been in storage for 10 years, I'd also suggest replacing both the plastic, screw-in, one-piece, in-the-tank, fuel sock/screen and the fuel filter, as well. No better time to replace those than when replacing the pump.

Hope that helps. Good luck.

curtisr

I find the parts catalogue to be of the utmost value when it comes to locating parts. For your model it's available here: http://www.porsche.com/all/media/pdf...91_KATALOG.pdf

There may be a cover but you want to find the line out of the tank (23) and, well, you can't miss it.

creaseuk

Thanks Both . Very informative. As an update I have isolated the fuel pressure regulator (as mentioned in the Clarkes Manual) and still no fuel at the rail. I'm fairly certain the fuel pump is new. I think I know where it is now thanks. The only other 'stupid' thing I think it could be is the new fuel filter fitted backwards?

creaseuk

I'm so excited !!! After fitting a new DME relay .. still no fuel or fuel pump noise.. So, I took your advice and jumpered the DME relay (i chose the paperclip option) as soon as I plugged it it I could hear the fuel pump working !!! I still have no fuel at the rail but....... I have a working fuel pump.. So, does this mean my new DME is faulty?

Rogue_Ant

If your fuel pump is running (and installed correctly), but there is no fuel at the rail, then you either have a blockage or no fuel in the tank..

creaseuk

Thank You Guys For Your Patience and Experience. I Have Been Inspired By Your Replies..

I found the fuel pump .. Its under that HUGE cover that looks like it's the fuel tank but isn't. Its even held on by a HUGE metal strap to make it look like a fuel tank..

I didn't need to remove the wheels either.. So When I removed it this is what greeted me ..

Attachment 750517

The Huge cover was filled with molasses looking substance and one of the hoses (23) was seriously buckled.. Looks like a source of fuel starvation. After removing the pump and filter (and covering myself in gasoline- more later) I could get a better grip on the problem..

Thankfully, I was using a filtered funnel to drain the fuel tank.. Thankfully because the mesh was catching the remnants of 'sock' that were coming out of the hole.. Not thankful that I was under the car when the mesh blocked and the funnel overflowed!!
So, after draining the tank I took off the fuel filter- Right away I could feel there was something wrong with the hose from the tank to the pump. It was 'melted' to the pump and the spout on the tank.. So this is what came out..

[ATTACH][/ATTACH]

The hose between the tank and the pump was perished so badly it was melting to the spout.. Then it was 'melting' from the inside to the point where it was effectively turning itself inside out.. If I tapped the pipe a whole heap of gunk came out.. As for the internal fuel filter in the tank .. Completely GONE.. Some of the remnants came out with the fuel.. some more were iside the spout but this is what it looks like :



I'm inspired by you guys that helped me find the problem.. But now I have a whole heap of work to do to find the solution.. Starting with a trip to my local NAPA for some fuel tolerant hose !!

Any more comments you'd like to leave would be more than welcome. In the meantime I'll be under a Porsche

Attachment 750522Attachment 750523

Thank You All Again !!!

Aeropooch

wow! that hose you pulled off along with the hose on the outer end of the pump is a common crimp up point when installing the bracket over the fuel pump cover. Be careful when installing that. That tank fuel filter looks really bad...I think there's suppose to be a screen there?

Legoland951

It is very common for fuel pumps to seize. I have 4 944s sitting in my yard for years and the fuel pump seized and I have taken apart many fuel pumps. The "pump" part under the electric motor inside the aluminum case of the fuel pump gets hardened evaporated "gas" and sometimes rust. These metal rollers have extremely tight tolerances and if there is gunk or broken parts of the rubber hose in there, it won't work.

Most of the time when a 944 sits and not start, it is due to the fuel pump. Hook up 12v to the pump and you won't hear anything.

Left side of the picture is a dissembled "pump" and the right side is an example of an assembled one: