Engine Start issue...

[Brett San diego]

Originally Posted by jrnicl3

Here is a picture I took to explain what I meant by "cut".

If you are saying that the fuel pump is in the engine compartment next to that hose in your picture, then you did not replace the fuel pump. So, what did you replace?

The fuel pump is under the front of the car near the fuel tank.

I'm with Gunter. Get a Bentley manual and do what it says, then come back if it still doesn't work. You'll avoid a lot of unnecessary chatter that is already filling up this thread.

Brett

[jrnicl3]

Originally Posted by Brett San diego

If you are saying that the fuel pump is in the engine compartment next to that hose in your picture, then you did not replace the fuel pump. So, what did you replace?

The fuel pump is under the front of the car near the fuel tank.

I'm with Gunter. Get a Bentley manual and do what it says, then come back if it still doesn't work. You'll avoid a lot of unnecessary chatter that is already filling up this thread.

Brett

Calm down Diego. Obviously I meant the fuel filter in the engine compartment. So anyway, I am testing the fuel pump right now and I will update everyone tomorrow.

[Brett San diego]

LOL. I'm calm. Just making sure. In your own words, "I'm new to it... I'm learning." You said the fuel pump was in your picture. I believed you. Be careful what you type. Buy the Bentley. Very worth it. If you won't be taking it to a professional, you'll want a fuel pressure gauge specific for the CIS system, as already mentioned. Once you get fuel flowing, you'll need to check the fuel pressures (system, cold control, warm control, residual), also outlined in the Bentley.

Good luck with it. Keep us informed with progress.

Brett

[jrnicl3]

Originally Posted by Brett San diego

LOL. I'm calm. Just making sure. In your own words, "I'm new to it... I'm learning." You said the fuel pump was in your picture. I believed you. Be careful what you type. Buy the Bentley. Very worth it. If you won't be taking it to a professional, you'll want a fuel pressure gauge specific for the CIS system, as already mentioned. Once you get fuel flowing, you'll need to check the fuel pressures (system, cold control, warm control, residual), also outlined in the Bentley.

Good luck with it. Keep us informed with progress.

Brett

Thanks for your help Brett. I did connect 87a and 30 withe a wire. I did not hear the pump when I turn the ignition on. Any suggestion?


Thanks

[Patronus]

Tony,

I went by the workshop manual (pictures above) and it is interesting that it doesn't apply to a 80 and 81. Thanks for pointing that out!

jrnicl3,

If you bridged the relay sockets as you did and hear nothing when switching the ignition on then it sounds to me like your fuel pump doesn't have power or may be defective. That is, if bridging them has the same effect on your model than on a 79 and earlier, which I believe should be the case. In any event the idea is to start testing the easiest thing first, which is the fuel pump. Before going to the extremes of getting fuel pressure gauges etc.

[boyt911sc]

Originally Posted by Patronus

Tony,

I went by the workshop manual (pictures above) and it is interesting that it doesn't apply to a 80 and 81. Thanks for pointing that out!

jrnicl3,

If you bridged the relay sockets as you did and hear nothing when switching the ignition on then it sounds to me like your fuel pump doesn't have power or may be defective. That is, if bridging them has the same effect on your model than on a 79 and earlier, which I believe should be the case. In any event the idea is to start testing the easiest thing first, which is the fuel pump. Before going to the extremes of getting fuel pressure gauges etc.

Patronus,

I know why this test does not work with the SC's. The '76-'77 have similar FP circuitry as the SC's. I never used this procedure because of the starter cranking and avoided using the factory procedure ever since. The factory shop manual is a super great reference book but the English translation is not that excellent. Which was done some 30 years ago(???). Have you actually performed this test on your car? Please advise. Thanks.

Tony

[Patronus]

Tony,

I went through this last weekend when I adjusted my own car's control pressure. It is a 79 SC so the wiring may be different on 80 and 81 models.

I bridged sockets 87a and 30 to get the pump running when the ignition is on, to measure the fuel pressure. I did not bridge the relay because I didn't have an old one as the book says and I though the end result would be the same. It worked perfectly and in fact I started the car and ran it like that multiple times until I was completely satisfied with the end result, and then I put the relay back. As I say, 79 SC may be different from later models.

[boyt911sc]

Originally Posted by Patronus

Tony,

I went through this last weekend when I adjusted my own car's control pressure. It is a 79 SC so the wiring may be different on 80 and 81 models.

I bridged sockets 87a and 30 to get the pump running when the ignition is on, to measure the fuel pressure. I did not bridge the relay because I didn't have an old one as the book says and I though the end result would be the same. It worked perfectly and in fact I started the car and ran it like that multiple times until I was completely satisfied with the end result, and then I put the relay back. As I say, 79 SC may be different from later models.

Patronus,

I've been working on several SC's and just a few weeks ago a member's '81SC engine was dropped at my place for some work. It was tested and run on the test stand using same technique like yours (bridging socket's terminals). Using the socket relay is not a problem. It is the 'bridged relay method' I'm inquiring. Why the factory manual recommended it is beyond me. Have you tried the 'bridge relay method'? Thanks.

Tony

[Bob Kontak]

Originally Posted by Patronus

Tony,

I went by the workshop manual (pictures above) and it is interesting that it doesn't apply to a 80 and 81. Thanks for pointing that out!

Woah - I said it does not work for an 80 / 81 - NOT TONY.

What I said (re 80 /81) is incorrect because when I did this procedure on a 1980 and 1981 the starter turned BECAUSE I WAS USING A GOOD RELAY.

THE MANUAL SAYS TO USE A SPARE RELAY (WHICH MEANS BROKEN RELAY BUT DOES NOT SAY BROKEN RELAY). THAT IS THE PROBLEM WITH MY APPLICATION

I AM YELLING BECAUSE I NEED MORE COFFEE - BACK IN A BIT.

[Bob Kontak]

Originally Posted by Patronus

I did not bridge the relay because I didn't have an old one as the book says ...............

AH-HA - this may be a simple language issue - Patronus says "old one" / book says "spare" but I think they both mean non-functioning.

It has to because a good relay bridged will spin the starter motor across all the years. EDIT: I also see where I am walking all over Tony's similar discussion. I will sit on the sidelines for a while.


JRNICL3 - Sorry - we will be done with this side bar issue shortly.

[Bob Kontak]

Patronus - Looking forward to your response to clarify if you are doing this bridging with a broken relay or a good relay.

[Patronus]

I have never modified an old or broken relay, just always bridged the socket (female). I can tell you one thing, if you only expect the fuel pump to buzz but in stead the engine starts running it will be a nasty and potentially expensive surprize. For once I'm glad that I was too lazy to follow the book.

[T77911S]

i dont usually jump in on something this long, but its a slow day at work.

wow, you guys turned this into 2 pages about a fuel pump relay. pull the connector off the back of the AFM if you dont kn ow what pins to jump or where the relay is, or just lift the sensor plate.

the car has been sitting for 4 years. could be a stuck plunger. could also be rust in the tank blocking the inlet screen.

pull an injector out, place it in a jar, turn on the key, reach inside the air box and on the left side, lift the air sensor plate.
you should feel resistance as soon as you lift the plate. if there is any "free" movement, with the fuel pump running, which should come on as soon as you lift the plate, the plunger is stuck.
you should hear the injectors squeal and fuel should spray out.


control pressures need to be checked too. a blocked return line or dirty inlet screen to the warm up regulator(WUR) could have the cold control pressure (CCP) too high.

[Bob Kontak]

Thanks!!

Both the fuel pump buzzes and the starter turns over but you are so freaked out by the starter motor that you don't have time to notice and you unplug the bridged relay.

Probably the biggest risk is if the car is in gear and it lurches forward or back wards - say, with the front wheels on jack stands.

OK - back to the original post. :-) Thanks again for your patience OP.

[Bob Kontak]

Originally Posted by T77911S

i dont usually jump in on something this long, but its a slow day at work.

wow, you guys turned this into 2 pages about a fuel pump relay. pull the connector off the back of the AFM if you dont kn ow what pins to jump or where the relay is, or just lift the sensor plate.

the car has been sitting for 4 years. could be a stuck plunger. could also be rust in the tank blocking the inlet screen.

pull an injector out, place it in a jar, turn on the key, reach inside the air box and on the left side, lift the air sensor plate.
you should feel resistance as soon as you lift the plate. if there is any "free" movement, with the fuel pump running, which should come on as soon as you lift the plate, the plunger is stuck.
you should hear the injectors squeal and fuel should spray out.


control pressures need to be checked too. a blocked return line or dirty inlet screen to the warm up regulator(WUR) could have the cold control pressure (CCP) too high.

All good info - and yes, I played a big part in hijacking this thread. Sorry to the OP.

I believe right now the OP cannot get his fuel pump to operate with either the Jumered relay procedure or the lifting of the air sensor plate.

[Gunter]

It drags on mostly because the OP doesn't make it clear what he's doing or what's been done or how to describe things correctly or give a timely response.

It's not unique.

A lot of threads start with asking for help, give confusing details, don't follow advise and when the problems ever get fixed, don't bother to tell the rest how it was solved.

[Bob Kontak]

Originally Posted by Gunter

It drags on mostly because the OP doesn't make it clear what he's doing

Sigh.... You are correct.

Fifty five-ish posts in this thread and the OP has lifted the air sensor, sprayed some starting fluid, took a pic of a fuel line and put a wire in the relay sockets.

I think when your serve-return-serve-return (tennis comparison) system breaks down the other posters think that if they post another idea maybe the OP will hear them and come out of the coma.

[Patronus]

Maybe the OP bridged the fuel pump relay as per the Porsche Workshop manual and when his wife turned the ignition on the car ran over him....

[boyt911sc]

Originally Posted by Patronus

Maybe the OP bridged the fuel pump relay as per the Porsche Workshop manual and when his wife turned the ignition on the car ran over him....

If this actually happened to our struggling friend, I know where to put the blame!!!!! OH! It is not you Patronus!!! You are safe. It's the factory shop manual that was poorly translated into English language.

Tony

[Bob Kontak]

Glad we worked through that even if it caused a disruption.

Edit - Well, Tony, did the diagram work............................... I just scanned a picture.