I finally managed to get on here. Like most others on here my mistress is a P38 and I've learned along the way to fix problems as I find them. Usually with forums to help, there are 3 great ones and this is one of them. The 2 best are Brit ones ;)
First things first - you NEED to get a Nanocom or similar on the car to chase the faults. I'm in Winsford, Cheshire so I'm too far away, but one of our Knights will probably help :smile: If you don't have your own diagnostics you will be wasting your time, chasing faults and garages will see you as a cash point machine.
Dave told me the garage had changed your leaking seals on the FIP. I have done this myself and managed to set it up again. The first time a "mechanic" did it it cost me a replacement engine.
If you have the hole cut under your back seat it is at most a 1 hour job. It's easier with 2 people (my wife [angel]) is my spare hands. On mine I can say that the intank pump (some call it a lift pump) fails around every 18 months. It's cheaper to buy a new one and install (or get someone) it yourself and part of this procedure is to install a non return valve between the fuel filter and the bulk head (the thick black pipe). If you have that installed then you won't ever notice that your in tank pump has failed until you check it. I think mine had failed for well over 6 months and I have a sloping drive and had all the "below 1/4 of a tank not starting problems".
Back to the story. My FIP had been leaking and the mechanic told me he'd one P38's before. He very obviously lied as it was awful after he put it back together and scarpered. No power at all and thick black smoke when I put my foot down. The only way to get anywhere was using the manual side of the auto gear box. I had to really rev the engine to get any acceleration. It would not accelerate in automatic and blew huge clouds of black smoke when I tried!
What I suspect is that he did not have the correct tools to hold the timing chain and slipped the chain.
I also had another problem that was a severe lack of power that wasn't related to the FIP. No power and unable to rev past 50 - 60 mph. It makes it feel like a failed clutch or failing gear box << Solution for me? MAF sensor - Dave3d let me borrow his. So a quick check for this is to unplug the big plug connector on the MAF sensor. This is the pipe between the air filter and the intake manifold and has BMW stamped/embossed on it and an arrow showing air flow. If your MAF has failed your car will drive like it has full power again once the electrical plug is unplugged. If you plug it back in and it's rubbish again that's your answer - they are not cheap though.
FIP fault: The middle section of the pump (second o ring down) is the part of the FIP that can severely change how your car drives and makes power.
There are 5 o rings / gaskets on an FIP (although I have one that only has 3, it has 2 steel gaskets instead of o rings as standard.)
O rings that leak - on mine they did :)
- Top gasket doesn't affect anything when you change it. BUT you do have to remove the anti-tamper triangle headed bolt. I used a 9/32 socket whacked on with a hammer and replaced this with a replacement bolt.
- Middle gasket this is the one is attached to a part inside (can't remember the name) that changes/messes with fuel quantity delivery. You NEED live diagnostics to correct this one.
- Lozenge shaped cover at the lower front - can be changed with FIP on the car, fiddly but can be done. Doesn't affect anything changing this one.
- Lozenge shaped cover at the rear - FIP has to come off. This is easy once you've done it once, but you need the correct tools. Not to be attempted without them.
- Where all the pipes go into the FIP there is another high pressure o ring. There is a home mechanic way of doing this and it CAN be done with the FIP still on the car. Get it wrong and you need to remove the FIP and a bit falls out inside.
I've changed all my o rings and gaskets. It takes a long time to remove all the bits to actually get to the FIP. Took me around 4 1/2 hours just to get to the FIP.
The FIP has static timing - from the timing chains. The chains stretch due to wear and tear and eventually this means that the FIP is no longer at the factory setting and usually get's hard to start. The electronics in the top of the FIP (top cover) mixed with the ecu can electronically adapt and allow for that but only up to a point. Then it needs mechanically static timing. You need special tools for this - but I did do this successfully. I can see why a garage would charge a lot of money, mostly labour to remove all the gubbins to be able to start the job.
This is one of my previous posts where I had corrected the middle section of the FIP being out of alignment
Just a few weeks ago swapped out my top and middle gaskets on the FIP and after asking Wammers on another forum (he is a retired mechanic and a serious FIP boffin - but he is cantankerous hahaha) the advice I got was this:-
Modulation is only adjustable via static timing and no other way. 95% is right at the end of the ability for the electronic brains to account for chain stretch and it will need the static timing adjusting sooner rather than later. My modulation is 67% but I will do static timing in the spring.
Twisting the pump only changes the mg/stroke (which is really mg/litre apparently) which should be between 5 - 6 mg/str for best running @ 750rpm, 128 is the correct fuelling value on Nanocom. To keep my rpm @ 750 I have to put my fuelling at 129 so you can adjust that. The dash rpm counter needle however shows around 775 on the dash, Nano shows 750rpm exactly, so I go with that.
If you haven't yet done it, the twisting and moving is a pain in the arse and will seriously test your patience! Slight tightening of one bolt revs go up, slight loosening of another and they drop, it's a balancing act it just takes time and cups of tea :) If you loosen the bolts too much if you don't spot it you will find a nice diesel smell, thats the pump pissing diesel out - so don't loosen them too much just enough to get movement.
I am in no way a guru I'm just passing on the same info that I was given so I hope this will help others as it did for me.
So correct measurements should be:
fuelling @ 128 on nanocom
modulation 50% (+/- 5%)
With new chains static timing is set at 0.95 mm lift at TDC. Over time as the chains run in and loosen up slightly it should drop to 0.9 mm static.
If I have missed anything out or got something wrong please feel free to correct me guys. I'm not a guru but I do believe in knowledge sharing as these forums have been a godsend for me!
I'm in Cornwall all week but can get on here in the evenings.
I hope it helps and I haven't bored you to death and I absolutely hate garages that take advantage of people.
Hoppy (and my long suffering P38 widow Kerrie)