In an attempt to determine my odd semi-hot not fully cold starting problem...Bill & I checked the fuel pressure regulator....only a drip came out of the return line....so that means the injectors or check valve are bad....so we decided to change the fuel pressure check valve and fuel filter (it was due)....

It turns out the whole assembly comes off the car pretty easy with just the 4 rubber bolts (on the outside) & it lifts up & off (once the gas lines and wires to pump are disconnected).....IF the frame that holds it is not bent...of course mine was....!?!?!?! We figured this out AFTER we fought with it to get it off......

The other major bummer on the check valve is the 17mm nut that is built into the check valve is very close to the +/- leads on the fuel pump....so close that a wrench wouldn't get on it......so Bill grinds down an old 17mm wrench.....& it fits, but isn't strong enough to turn it.......since the pump was off....it would spin the 17mm check valve...until the fuel line hit the +/- leads from the pump !?!?!?!? This is getting annoying.........so we gently grind down the pump leads to allow it to spin under the fuel line.....this gets the pump out of the check valve.....of course this was easier than grinding down one of Bills wrenches...& ruining it......but of course hindsight is 20/20.....so I owe Bill a 17mm wrench...

Everything went back together pretty easy after that......despite the gas all over the place.....one odd thing I noticed was the gas that poured out of the filter the direction the gas flows(towards engine) was clear......the gas that poured out backwards (towards tank)...was nasty....all black and full of sediment....looked like oily sand.....

Now the car runs fine & we'll see if this fixes my odd just barely beyond factory spec fuel pressure loss.....the only thing left is injectors.....

Thanks to Bill for his help and "donation" of a 17mm wrench....I wish I brought my camera to take pictures....

 

What you said about the gas being dirty sounds logical to me. You said the gas on the tank side of the filter was dirty. That would be correct since it has not passed through the filter yet to be filtered.

 

Gman
I thought it was because the filter was poured backwards....which allowed all the gunk that has been trapped for almost 8 years (filter was dated 6-23-99) to get release by a backwards flow.....I really HOPE that my Chevron gas @ $3.56 a gallon I just bought this morning is a touch cleaner than that junk!

The good news is I started sharky 3 hours later....& it started fine...vs it not starting on the 1st crank before!! :>) I guess it was worth it!

 

Looks a bit like this?

I was amazed that is was this bad....

Theo

 

[QUOTE=IcemanG17]In an attempt to determine my odd semi-hot not fully cold starting problem...Bill & I checked the fuel pressure regulator....only a drip came out of the return line....so that means the injectors or check valve are bad....so we decided to change the fuel pressure check valve and fuel filter (it was due)....

Hi Brian,

I'm having a problem changing the filter with freeing the nut on the fuel line at the outlet of the filter. It's the 19mm one and you need to counterhold another 19mm on the filter itself.

How easy was it to get this off on your car? Any special tool/technique used?

Thanks

 

Long wrenches for leverage sure helps. I don't recall a big problem with the filter fittings....Oh, wait a minute...there was a fitting on the filter that we had to remove AFTER we took the whole package off the car, but it was 17mm with a 19mm counterhold. The 17mm started to round. Anyway, we ended up putting that in a vice while the whole filter and pump assembly was still together then cranked on the 19mm with a wrench. That did the trick.

 

try spraying some PB blaster on the fittings a few times , on the reinstall use a bit of anti seiz on the threads and the pipe fitting where the nut pulls the on the fuel line, the anit seize will help on the next go round

 

Jeezez, Stan, you getting up for work already?

 

Thanks Bill - most people don't seem to have a problem with this particular nut so it's just my 928 jinx!

 

PB Blaster (or rather a not very good substitute - can't locate PB or Kroil here in UK) soaking in as I type.

I also have a freezing spray to try which is supposed to be good on stuck fittings.

Definitely anti-seize if/when it come off so thanks for reminder!

 

I've just finished work on replacing the check valve. I gave up on trying to undo the damn nut at the fuel filter outlet so turned attention to fitting new valve I'd got to see if it cured warm start problem.

I found that after clamping/removing the fuel hose to pump, undoing the cap nut on banjo bolt, taking off power leads, loosening clamp and sliding pump to left I could remove it with fuel filter in place.

Was then able to use a 17mm socket to take out the check valve (just using hand to counterhold the pump), which fits with no problem between the power posts.

Fitted new valve and new crush washers (3), re-connected everything and fired up. No leaks!

The warm start issue seems to be cured too. Have left S4 for varying periods after starting and it's starting first time each time with no need for slight throttle which used to be case for warm start (it always started almost instantly from cold).

So may have fixed the problem and maybe I don't have problem with pressure regulator, dampers or leaky injectors. Time will tell.

Now off to wash off all the fuel up my arm!

 

Theo
Maybe not that bad.....but the same color for sure!! The can itself was cleaner...