[nifi]

Hey all,



Help please! <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" /> I did a recent belt/roller, water pump and front eng. seal. Ever thing is finished, but I do not get any fuel pressure. <img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" /> I have changed the DME and by passed the pump and it runs. I'm not sure what else to look at.



She sat for a few months between start and finish. I did pull the battery and had it on a trickle charger.



Any help would be great.



Thanks,



Matt

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[nifi]

[quote name='nifi' post='62194' date='Oct 25 2008, 01:13 PM']Hey all,



Help please! <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" /> I did a recent belt/roller, water pump and front eng. seal. Ever thing is finished, but I do not get any fuel pressure. <img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" /> I have changed the DME and by passed the pump and it runs. I'm not sure what else to look at.



She sat for a few months between start and finish. I did pull the battery and had it on a trickle charger.



Any help would be great.



Thanks,



Matt[/quote]



Well I think that I got, nothing like answering your on question. There was another post on by passing at the leads in the fues box. The pump runs there, my replacment relay is bad too.



matt

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[nifi]

<img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" /> I lied the relay did not make any diffrence. I do not hear the fuel pump at all. Any one got an idea?



matt

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[flash]

start at the beginning



verify power at the battery



verify power at the key



have you verified power at the relay?



can you get the car up in the air?



if so, verify power at the pump with key on



there is a ground there that could be bad too

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[nifi]

[quote name='flash' post='62262' date='Oct 27 2008, 04:31 PM']start at the beginning



verify power at the battery



verify power at the key



have you verified power at the relay?



can you get the car up in the air?



if so, verify power at the pump with key on



there is a ground there that could be bad too[/quote]





I have spark when turning over. I have by-passed the pump both at the relay and at the pump with no problem. I have changed the relay twice thinking it was bad, is there another relay? Fuses are all good also. The strange thing is that ever thing was fine prior to the belt change.

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[xrad]

I am pretty sure the fuel pump will only run when car is in ignition 'run' position or you have bypassed this safety feature.



is there gas in the tank?



Check for 12v at fuel pump when cranking(takes two peolpe).



If you have proven the pump works, time to move to something else.



after cranking, pull a spark plug or two and you should smell gas!



COuld the cam timing be 180 , unlikely, but maybe?



Also, check crank positon sensor for 180 out position.



Injector blinkers will prove injectors have power.

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[blue968]

HI,



DO YOU HAVE ACCES TO A FUELL PRESSURE GUAGE TO SEE IF THERE IS ANY PRESSURE WHEN THE KEY IS TURNED ON???

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[flash]

i think we have a terminology issue here



if you bypassed the pump, then you would have no pump - do you have power at the pump? it should show power, though possibly not run until the engine is running or pressure is released



there is a hot wire jump trick you can do at the relay pins to run without the relay - i believe it is pins 87, 87b and 30

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[nifi]

[quote name='flash' post='62277' date='Oct 27 2008, 07:11 PM']i think we have a terminology issue here



if you bypassed the pump, then you would have no pump - do you have power at the pump? it should show power, though possibly not run until the engine is running or pressure is released



there is a hot wire jump trick you can do at the relay pins to run without the relay - i believe it is pins 87, 87b and 30[/quote]





Flash,



You are correct I jumped the pins and pump runs. I have 1/4 tank of gas. Everthing was kept at TDC during belt change. I will have to pull fuel line off and see if I get any pressure.



matt

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[S_Cal968]

If the pump is running than the next check is the pressure at the fuel rail.

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[flash]

cool - glad that helped eliminate one issue



yes, check the fuel pressure - could be as simple as a clogged or faulty regulator, jammed line, yada yada



BE CAREFUL - high pressure - about 50 lbs - this can be messy and dangerous - wear eye protection

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[Dano]

And of course a fire extinguisher(s)! My cousin lit himself on fire accidentally this way.

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[Dano]

Oops, got ahead of myself.



Meant to add:



I'm also having a similar problem...



Car stalled at traffic light, won't start - towed home. I've jumpered the DME relay pins and fuel does pump run. Checked fuses, a few other things, checked spark (which I have none). So I'm thinking it might be the crank position sensor as XRAD stated. So far I haven't found a way to really test it without replacing (unless you have an oscilloscope). Or maybe someone else knows?



If you decide to replace the crankshaft position sensor; I've also found, via the forums, a less expensive replacement. Use BMW part instead of Porsche (about $100 less). Only difference is the length of the pigtail connector on the BMW is longer than the Porsche, so no biggy there.



Bosch P/N (Porsche): 0261210003

Bosch P/N (BMW): 0261210002



I found it here (dunno if I can paste URL's or not, if not google autohausaz dawt com):

http://www.autohausaz.com/search/product.a...mber=0261210002



Good luck on your gremlin (err Porsche gremlin that is). Post your progress if you can.

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[nifi]

Well, I went out to see if there was fuel smell when I pulled a plug. There was but not overwhelming. I now have no spark??? <img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" />

At this point I'm going to wait to the weekend and try going step by step. I have an after market alarm that was on the car when I bought . I thought that

might have some thing to do with it.



Thank you for the help! Any other ideas are very very welcome.



Matt

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[DaveN]

[quote name='nifi' post='62374' date='Oct 28 2008, 09:11 PM']Well, I went out to see if there was fuel smell when I pulled a plug. There was but not overwhelming. I now have no spark??? <img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" />

At this point I'm going to wait to the weekend and try going step by step. I have an after market alarm that was on the car when I bought . I thought that

might have some thing to do with it.



Thank you for the help! Any other ideas are very very welcome.



Matt[/quote]





I'm not sure how similar the DME is from a 944 to a 968 but they were probably made in the same factory so....

My first 944 was just dandy until I move the DME around one day looking for a leak from a windshield leak. After that it would just die while driving and not run for 10-20 minutes, sometime for days. Then, Vroom away it would go again for a random amount of kilometers. Anyway, I ripped my hair out over fuel relays, pressure regs, fuel filter, the whole gambit for weeks until one day I tapped on the DME while the car was running an it quit. I tapped on it again and the car started, magic!. Opened that bad boy up and laid out the circuit cards and went for a drive with my son in the passenger seat. I had him systematically push on certain components until we narrowed it down to a power transistor and surrounding area. I brought it back, put it on the bench and resoldered all the components around that whole area. Didn't work the first time so I ended up resodlering the whole board. Ran like a dream after that and no amount of banginh on the DME would sop the car.

Point is, it's Bosch, from the same era, you are having random fuel, ignition problems and you just disturbed the car components by working on them.

Hope this helps.

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[Dano]

Hmm, maybe I'll take the DME out and do some solder work since I'm waiting for parts to arrive anyhow. Might as well do something useful while I stare at it. LOL

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[DaveN]

[quote name='Dano' post='62404' date='Oct 29 2008, 02:51 PM']Hmm, maybe I'll take the DME out and do some solder work since I'm waiting for parts to arrive anyhow. Might as well do something useful while I stare at it. LOL[/quote]





Just took my DME out last night in prep for the RSBarn chip, I chipped my S2 so why not the 968 <img src="/forum/images/smilies/968/rolleyes.gif" class="smilie" alt="" />

I see Bosch has redesigned the unit to a single mil-spec dual layer fibreglass board with surface mount components. DO NOT re-solder this board as previously suggested, you will only make things much worse. The old DME I had in my 944 was from the stone age and you could work on it at home with not much more than a good Fluke and a soldering station. This re-design is way beyond that level of service.

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[unknown4u]

Yep, open a new 993 relay and you can see the differtent between stone age and modern times.

The 993 relay is very reliable. I'm pleased with it. I did have the same zstupid experience with it. You think it works right but it gives you a pain in the a..

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[nifi]

Thank you all!



I final admitted defeat and had her towed to my local Porsche mechanic. The CPU had gone bad. The timing was off by a few teeth, but fuel pump, DME, and ignition system were fine. Go figure.



Thanks again,



Matt

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[kwikt]

[quote name='nifi' post='63404' date='Nov 23 2008, 12:05 AM']Thank you all!



I final admitted defeat and had her towed to my local Porsche mechanic. The CPU had gone bad. The timing was off by a few teeth, but fuel pump, DME, and ignition system were fine. Go figure.



Thanks again,



Matt[/quote]





What's the CPU? Thanks!

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