Overfueling now, 944 Turbo - updated Fixed with pics

[Gary C]

ORIGINAL: diabloam Anyway, defo no clicking noise from TPS going onto idle and back off (should click each way, yeah?) so took it off and popped top of it. The sliding contacts look ok and resistance seems to change smoothly al la Clarkes guide test procedure. But it looks to me like the microswitch is jammed in, although given I have never seen inside one of these, I aint sure. Anybody want to look at this pic (in small album below) and tell me its not an inductor type pick up and that wee plunger looking thing on side of TPS (wee round thing on white microswitch inside TPS) that the throttle/TPS Slide contact goes against when returning to idle, it should be sticking out when TPS is turned away from against it but in the photo it doesnt, it looks stuck in, anybody? [link=http://s701.photobucket.com/albums/ww14/diabloam/TPS%20and%20Running%20probs/]http://s701.photobucket.com/albums/ww14/diabloam/TPS%20and%20Running%20probs/[/link]

Does not look correct, never looked at a 944 TPS, but from experience with microswitches it looks wrong. If the button has broken off, rather than stuck in, it would be permanently in the running position ?

 

[diabloam]

Well, got a AFM and TPS today from Sulzeruk (much appreciated), stuck TPS on and it clicks now on and off idle so sorted that. Tried car, but still smoking and running rough. I think there is a good bit of petrol in the oil (hope that hasnt done any damage) and am thinking even though I might have fixed the problem, that contaminated oil is going to make it run rough. So have got some 10/40 and a filter, just sticking them on. Oil that came out was fairly thin looking so hope everything ok. Anyway will try it with some fresh oil and see if its any better. Does everybody agree that the petrol in the oil would make it run rough? Going to see what this its like and post back, cheers

 

[sulzeruk]

Hi Alex, try the AFM and I think that may cure your problem, Alasdair

 

[diabloam]

Will try the AFM tomorrow and see how that goes. Have also ordered a new fuel pressure regulator from Porscheshopgb and a baileys dump/recirculating valve and fuel rail pressure gauge from Promax. See if I can also see what going on with pressure in fuel rail. Hopefully cause I have ordered these yesterday, I will go out tomorrow and put AFM on and it will run perfectly. One case of sods law Ill take right now, lol. Will post back and let you know. Changed the oil as was worried about the stuff in it, really hope I havent done any damage there, hopefully it'll be ok, thanks again

 

[diabloam]

Quick update. Didnt get much done last couple days, but got back to it today. Is it possible for petrol to get into oil even if the car has not really being running, cause am sure I can still smell petrol from dipstick depsite changing the oil and only have run car for minute or two(running roughly) or is it just a residual smell (do the injectors ever leak?), although that would only explain overfuel on start up as only the contents of the fuel rail could leak in whilst car is sitting, so am thinking it is just a residual smell I am getting since it went all over the floor when drianed old oil (badly positioned basin I attempted to drain into, lol). Anyway have changed most of the vacuum hoses and have put on a new rotor arm I had sitting since last time I changed the distributer cap. Going to use the other AFM and put on a new FPR that I a waiting to arrive in the post along with fuel rail pressure gauge and DV30 recirculating valve. Will post back, meantime anything else I should be trying let us know, hopefully one of the things mentioned will sort it. At least got chance to look at belts whilst lot of pipework was stripped off, visual check is ok, so can leave that hopefully till get running probs sorted, thanks all

 

[peanut]

ORIGINAL: diabloam (do the injectors ever leak?),

yes of course and the fuel rail and system is held at 3 bar pressure which gradually reduces over time. An injector could leak quite a bit of fuel. When you get your fuel pressure gauge you should do a pressure loss test as well . Check Haynes or Clarks for the test criteria Until you do these basic tests you are not going to be able to eliminate the injectors or FPR Did you ever try disconnecting the electrical connector to one injector and running the engine ?

 

[diabloam]

.Was playing football the night so didnt get as much done as I hoped. I had ruled out a leaking injector, cause from the look of the plugs there were all sooty, and given its unlikely they all started leaking at once I was thinking the cylinder with the leaking injector would have the most fouled plug (does anybody think my logic on this is wrong). Anyway got my bits the day, have stuck on the little fuel rail gauge straight on the end of the fuel rail as thought it should clear the bonnet when its closed, although not sure if it will (kit comes with couple of 45 degree angle adaptors to try lower it(anybody got this, do you need to use them, instructions says maybe, I wanted to try do without as of the opinion the less joints round the engine bay the better. Anyway car was sitting couple of days so wasnt expecting rail to be still pressurised, and indeed it didnt seem to be when I cracked the union, although fuel dripped out the whole time I had the end of rail open. Also stuck on my new FPR and have started putting it all back together should be ready to try things the morrow. Will be using AFM from sulzeruk and also known good TPS so hopefully I have done something to sort it. Will report back, hopefully with an idea of the fuel pressure. Has anbody else seen leaking injectors much on our cars? cheers

 

[peanut]

yes you are probably right but then the late cars have an additional cold start injector which enriches the fuel when the engine is cold. It is controlled in part by the water temp sensor on the head and partly by a timer in the ECU which connects and disconnects the cold start injector ground. That injector can cause over-rich running and foul all the plugs so I suppose its possible one main injector could do the same thing. I'm more inclined to think the ECU is pulsing the injectors too much giving a fuel rich mixture because of a faulty sensor input . Either that or a vacumn leak or a faulty FPR with stuck shut valve . If the fuel system was over-pressurizing due the FPR then disconnecting one of the injectors would usually improve the running /starting Good luck tomorrow

 

[diabloam]

Well I know there is something on clarkes garage about if the FPR fails and pressure is too high the injectors draw more current which can shut down the driver on them. So dissconnecting one lowers the total current draw and allows the engine to run. But I thought that was if it was actually not starting or at least cutting out. Mine just seems to be running crazy rich. Will need to see what its like with these jobs done. You are also right about the sensors throwing the ecu off. Am going to try the temp sensors whilst I am in there. It says on clarke garage to dissconnect the plug to the DME and test such and such a pin outs resistance through ground. Can you get the same result just by unplugging at the temp sensor and putting the multimeter across the two pins on the sensor itslef, or do I have to unplug the DME unit and do it there, cheers for posting Peanut and everybody, advice on here is great and hope I can return the favour to everybody, will post back how it goes, thanks

 

[diabloam]

When you put a jumper across terminals 87b and 30 to energise the fuel pump, do you need the ignition on? When I put jumper cable across these terminals nothing happens until I remove it, then when it dissconnects the turbo coolant pumpe runs for its normal 30s. Do I need to jumper this with the ignition on? Want to check for leaks without and pressure in rail without running the engine, anybody help?

 

[egan1]

A three way jumper across terminals 87, 87b and 30 will energise the fuel pump. Ignition does not need to be on.

 

[diabloam]

ok will try that, it was just that it only mentioned two terminals 87b and 30 to power up the pump in the fuel leakdown test in clarkes garage, I though the other terminal would be for the DME. But are you saying you need to jumper all three to get pump going? Checked the resistance across the two terminals on the DME temp sensor (the temp sensor closest to front of engine, think one further back is for the guage) and it was 4.26k ohms, its higher than the 15 degree centigrade value in clarkes guide but it also is not as warm as 15 degrees here today. So does this sound ok? Thanks all

 

[egan1]

Sorry, you should be ok with 87b and 30, as 87 is for DME and injectors. 4.26k seems a bit high, I've previously tested 3.57k at 13.5 degrees.

 

[diabloam]

yeah but jumping 87b to 30 does nothing until i take the jumper cable out then the turbo water pump does its customary 30s running as if you had just switched the ignition off. No fuel pump runs, or not that i can hear and the gauge i have fitted to fuel rail doesnt move so its basically not running. Do I need the ignition on to do this or do all three pins need to be jumpered It would have been a little below 10 degree ambient temperature here today, so does that explain the 4.26 k ohms. Even if this was reading a false colder temp it shouldnt make it run that mcuh richer than it was doing. Any suggestions to the above? Cheers all

 

[diabloam]

jumped 87 87b and 30 and nothing happens, just the turbo coolant pump coming on when you disconnect. Fuse for pump seems fine, what am I doing wrong. Can I energise it just by trying to start car and risk that my connection on FPR and fuel rail gauge are ok? Surely it unlikely my pump has choosen this moment to fail? can see what its not powering up though!

 

[peanut]

from Clarks Garage 'The DME relay actually has two relays / contacts. The primary relay and contact provide power to the DME (and on turbocharged cars the KLR) control unit. It also provides power to actuate the secondary relay. The secondary relay provides power to the fuel pump' The jumper wire should go from terminal 30 to 87 and 87b termial 87 supplies the DMEand injectors and terminal 87b supplies the pump. With this in place the pump will flow continuously

 

[diabloam]

Well I went out and was pissed off so got my mate to watch for leaks as I just started the car up. Idling fine, sounds fine and revs up fine, still a bit smokey though but running much healthier. Would it be a fair assumption that smoke might take a while to clear since it was overfueling for so long? Maybe some in the exhaust etc, or should I be worried. Its not blue, defo looks like unburnt fuel, should I take car for a warm up and see if it clears? Anyway fuel pressure at idle was about 29psi which appears to be perfect. Also switched it off and left it for 20mins, pressure seemed to drop after first five mins to approaching 20 but when I checked after 20 mins it was above 25. The pressure given for leakdown is 1bar (14 odd psi) after 20 mins. I assume you are just looking for that as a minimum and mine staying up in the twenties is fine, that correct? I seem to be able to close the bonnet with the gauge on but cant tell if its a close fit or even whether it actually might touch when engine is running? I was thinking maybe put a wee pillar of blue tac on it and close bonnet and see how much it squashes it, reckon that might be an idea.

 

[peanut]

sounds like our posts are a day apart lol[] glad you got it running . Give it some mileage and see if the smoking settles down

 

[diabloam]

Know what you mean, lol. Car fired up great today, checked the levels and off out onto the open road and its like when I first got the car, great pull, no missing, no hesitation, delighted. I am now guessing it was the fuel pressure regulator or possibly the AFM as they were last things I swapped out before I put it back together. Have taken the fuel pressure gauge back out as was worried there was not much clearance between it and the bonnet and was too comfortable with the 2 45 degree connections you get with it from Promax, beside can always stick it back on when find a more reassuring arrangement. Going to give car a good thrash tomorrow and hopefully it will stay behaving itself, cheers for everybodies help, thanks, will post back with pics of the gauge so you can all see how tight a fit it looks to be with bonnet down

 

[peanut]

thats excellent news .! Very satisfying to fix it yourself too. Hope you have a great thrash around the lanes today. Good weather for it anyway.