Hi All! I was a Rennlister about 10 years ago when I had my 944 turbo and 944S but apparently my log-in info is gone so I am starting over fresh.. Hi and it is good to be back in the water-cooled Porsche corral again! I am located in Atlanta and have been racing motorcycles, building turbo Volvos and most recently a 635csi with a euro 745i turbo motor with a bunch of other little mods- Anyone in Dunwoody out there?

So – I ended up with this 1984 (at least that is what I was told) 928s Auto. It was given to me by a friend… so with that- any free Porsche, is probably one you want to run from!!! But it was driven to where it was parked 5 years ago without issues (so I am told ) so I know there will be a lot of little resto repair, but I have dealt with this before with my 635 and the old 951 and 944S… as familiar as I am with Porsches, this one seems just a bit different! Lots more cylinders -

To the issue: I have a Manufacture date of May 1984 …. So a late year 1984 I am guessing (I would have usually defaulted to an ’85, but he said 84) this is where the rub starts… so I have been doing a bunch of research in my quest to wake it up (I didn’t just start a post in hopes someone would just figure it out for me… but ill take it if its offered!) and it appears the ’83 and ’84 US cars (m28/20 -81e06850) use L-Jetronic as opposed to CIS and LH-Jetronic and I am finding little differences with the Fuse Panel naming and whatnot.. so I am trying to figure out the fueling system specifically as I have a NO Fuel situation. I have replaced the fuel pump, drained the tank and checked the relay.. all seem good, but I am getting nothing on the fuel rail (literally – on the pressure gauge or if I jumper the fuel relay and leave the rail open at the inspection point- at the end) I am going to replace the filter and start checking for flow as I do this… but this is where my question starts-

Is there anything that would completely impede flow like this- such as a vacuum line or a relay on the AFM that will allow power to the pump, but no flow. I know there is a little grid like filter thing in the tank, but the fuel came rushing out when I pulled the line to drain the tank- so that isn’t COMPLETELY stopping the flow… could be something in the filter, but I have never seen a fuel system run dry from a blockage- it will usually just slow it to a trickle… When I pour fuel in the intake, she lights right up and runs quite well for being dormant that long truthfully- haven’t even changed the plugs or anything and best of all she isn’t pouring any fluids out on the ground… yet

I have found the threads associated with getting a CIS car going and some others that have lead me to some points to check out and I will continue to do so. I am changing everything on the fuel system as I go along and I will be posting pics (she is a bit ugly right now!) when I get her painted.

Any assistance would be great and I will keep a little diary to post when I get it going so the next guy can reference the odd ball year, but I wanted to get the intro to me and my problem out of the way first!
THANKS!

 

Check the VIN - It should go "WPOJBO92??..." If the 10th digit is an E it is an 84 model. An F indicates 1985.

Try here: https://www.928gt.com/t-8384fuse.aspx or https://www.928gt.com/t-8586fuse.aspx for some fuse panel charts. I do not remember the correct fuses to jump, but there are several posts on here with those.

If you have the in-tank filter (sounds like you do) you may want to read up on those here. Many people remove them because of worries about them disintegrating and getting sucked into the fuel pump.

Good luck. I am sure others can provide you more help than I can!


Edit: Also, this may be worth reading: http://foxed.ca/rx7manual/manuals/BO...n%20Manual.pdf if you are curious as to how the L-Jet works

 

Awesome- one question already down - it's an E... So 84 it is! Thanks

Im reviewing the links now and taking it all in... I have a filter canister next to the pump... ThAt is what will be replaced and going to jumper the pump when I have it off to make sure we are getting fuel at least that far.

Thanks again!

 

Go to 928 Specialists website for the CE panel layout.

I'd bridge the alarm at the Z plug in center of panel first, to take that potential interuption out of the equation.
Build a double ended female jumper wire. Link Z4 and Z6. This is the combination ONLY for model year 84 and it works for Euro and USA versions. Picture below. Just leave the black Z plug laying on the floor board.

Then, jumper the fuel pump relay 30 to 87.

Then build a three way jumper for the injection relay. 30 to 87 to 87 or 30 to 87 to 87a depending on how it is labled, same thing. Must be three ended wire.

Critical grounds for all engine electronics and injector harness are on the pass cam cover.
One of them is visible, the other hidden under the air pump emissions valve which must be removed for proper cleaning and access.


Replace ground strap at bat neg in trunk, regardless of how good it looks. Can use a cheap advance auto round cable. Don't overlook this, don't bother trying to test it.

 

No worries - happy to help where I can. There are a bunch of very helpful people with more knowledge here too.

I would look at part 3 of this before you remove the filter.
http://www.kondratyev.com/porsche/te.../fuel_pump.htm

 

On the 84 cars its often relays and grounds that have slowed me down.
I like to polish and re fuse the CE panel too.

The fuel pump ground is hidden with a few other rear lighting grounds behind the right rear interior quarter panel.

 

The alarm was the first thing I did- that was keeping the fuel pump from starting. I am going to jump the ignition relay tonight and start taking stuff apart, cleaning and putting back together... Get that stuff out of the way- might stumble upon it! Going to check for ignition pulse too.

 

Great way to start, so to speak!

I've woken 3 84 USA cars and 1 Euro in the last 4 years, bringing them all back to reliable DD status.

Seems like the electrical panel, new fuses (old style VW ceramic body ones or plastic body equivalents) and the FP and Ignition relays, and grounds were the most important. Ground strap, too, and battery positive little red lead.


Then comes replacing sensors temp II and thermo time, both in front water bridge area, one vertical one horizontal in orientation.

And vac leaks so the barn door on AFM indeed opens as engine cranks. MAF and crank position sensor on Euro.

Those were the items that made the difference. Cap and rotor of course too. New fuel pump of course.

Noid light is very helpful.

Oh and one shorted injector wire takes them all out. But unless the boots look really bad, I don't go there at first.

 

Then youre the man to be talking to!

That last part there about Vacuum leaks for the AFM - I am somewhat familar with potentiometer style that will not allow fuel if the barndoor isnt moved upon startup... not allowing fuel to get to the injectors (or not allow injectors to fire- but that isnt the current problem)

I do remember seeing the little red wire on the positive cable being loose-

I plan on doing the whole belt/ pump and sensors replacement/ cleaning when i prove beyond a resonible doubt it will be worth it- i.e. not overheated when it was parked!

I am making the trip to the Atlanta Napa Dist. branch to get the fuses, filter, neg. lead and i have an eraser to clean the CE panel.. just need to locate the 2 realys now and get them on the way.

Thanks again guys- much appreciated!

 

Phil,

First question - You never specifically said whether or not the fuel pump is running. Do you hear it whine or buzz when it is jumpered?

If the pump is running, check the fuel line under the car for flattened areas.

It is also possible that the fuel pressure regulator has failed, and is completely blocking fuel flow.

 

Sorry about that- yes I can hear the new FP running away and it is actually quite loud with the inspection panel off... I was afraid of the FPR blocking everything and was going to remove and inspect- going to pick up my mighty vac tonight to check. But that is one of the only places that could completly stop flow I tought- looks pretty specific too, prolly not cheap! Maybe a couple wacks with the back of a screw driver might change its mind ( just kidding of course..... I would use a hammer :-)

 

Okay- so I went to put the fuel filter in and for giggles I thought I would check flow at the pump..... Nothing.... Which explains why it was loud. Never ASSuME anything- the direct replacement pump I got (forgot from whom, but blue and same diameter) had flipped flopped terminals so it was running backwards. I was wondering why it came with additional small and larger diameter terminals- I know why know- it wasn't direct replacement!
Flipped them, reinstalled a new filter- primed it up with the jumper on the fuel relay (which quited the pump down nicely ) and fired on the first revolution..... And died after a few seconds which from my previous reading is a different problem all together. Due to my 7yo's window being just above where I am working- the wife nixed any additional troubleshooting tonight- but I count that as a WIN.... Currently at least for now.

I still am going to go swap and check grounds, plugs and all that jazz and move to the running problem- but I feel the sitting probably contributed to that.... Back to research!

Thanks guys- y'all have been extremely helpful and I haven't been flamed once like some of the BMW forums I am used to! I will continue to post my findings in hopes to help the next pour bastard walking down this road!

9

 

I don't know how many times I have caused myself trouble by ignoring that kind of little nagging worry.
I think, "That's odd..." and then drive on and find out later that I should have thought about it a bit more.

 

Wow, nice work.

 

Ha! Not there yet....

I figure the injection relay is probably the culprit. Hopefully swapping that and cleaning all the fuses will net me a working fuel system and windows that work!