Steve J.

Don't give up yet and do anything rash. It might be close to running. Assuming it ran after the mods, it might be easier to go back to the last thing that worked. You can do a visual inspection and some testing without knowing what anything is. Basic stuff like checking for grounds, voltages, blown fuses, broken wires, bad connections, fuel pump working, etc. Fuel+air+spark+compression=bwaaaaahhh. Might be worth a shot.

V-Fib

My suggestion is one you probably don't want to entertain, but you should think about it. Sell it or even part it out. You will come out even at worst. Take the cash and buy another 928.

ViribusUnits

Bascily everything from the surfrace of the block, heads, and camshaft covers, north. IIRC, the L-jet motors bolts don't match up to the CIS equipment.

It would probably be easyer, and cheaper, to just go buy a used CIS motor from somehwere, and then sell the one you've got. If you can it, get a Euro S, if not a 79 US motor would be fairly readly avalible.

autochicago

You are in over your head. I would check the #'s just to make sure it's not stolen and sell it to one of the likely willing buyers on the list for the parts (even if it's at a small loss... you are probably much better off). I know how these things go... even with expert mechanical/electrical troubleshooting skills you can easily get yourself in for thousands of dollars ... and the car in question ain't worth it... heck ... a NICE pristine 928 can get you in for thousands in parts in the blink of an eye.

It's a painful pill to swallow but who knows what else is lurking just given what you've stated so far.

ViribusUnits

Damn, thats such a pretty car. I love that color. And an LSD, and a 5 speed. Damn. You'd better not offer me a trade, cause I'm too tempted. Shoot, I already know several junk yards in Houston with L-jet 928s in them.

Mind you my car isn't perfect, not by a long shot. I've got a shabby interor, destoryed a/c clutch, crappy paint job, rusted out ansa muffler, no cat, open differential, and worn syncros. Oh, and the damn S4 bumpers in a kinda strange conversion that a PO did. But the motor runs like a top. Something of a work in progess. If you want to talk about a trade, tempt me, cause that car is DAMN tempting...

One thing, I wouldn't worry about the millage on the engine too much. Age and neglect kills these cars, not miles. The block is that high silicon embeded stuff that's just about indestructable.

Anyways, to help you with your trouble shooting, have you found the ECU? It SHOULD be somewhere in the passanger compartment, assumeing the guys who did the conversion did a half assed job. If the ECU is NOT in the passanger comparment, I would suggest you don't drive the car. The ECU isn't designed to take the vibration and heat in the engine bay.

There should be more than three wires headed to the engine bay. There should be a bundle of wires going to the engine bay from the ECU and relay pannal.

Thom1

Here are some rough notes I have written or captured.

Check the rear hatch battery area first. Forward of the radiator at highest point are connectors. Make sure all connections are firm. Polish all ground points. Charge the battery. Don't disconnect retro wiring at fuse panel yet. Sometimes, you can hold the gas pedal to the floor while cranking to fire it up.

I have had starting problems at the positive battery terminal connecting wires, and above and forward, under the plastic cover. Connections must be clean and tight.

Notes follow:

I polished up some ground data with some connector maintenance. See link below that works now:
https://rennlist.com/forums/showthre...ghlight=ground


See some discussion quotes below about the 7 grounds per the FSM. I’ll add 3 more.

Maintenance:

Coat all electrical connectors with DIELECTRIC GREASE after cleaning/polishing them to enhance conduction and prevent corrosion. Assure that all connections are tight, but not over-torqued.

I would clean every electrical connector I could find. The blade connectors are self cleaning. Cycle them in and out a few times to shine them. You can also use scotchbrite, sandpaper, point files, tiny round files, etc. to polish connectors. For the plugs with 8 or 10 round pins, I use scotchbrite on the male side, and a small round file on the female side.

Replace all old fuses with new ones even if they work perfectly. Be sure to use the right ones. Cycle fuses and relays in and out to polish connectors. See this link, courtesy of 928 Specialists, for fuse and relay charts: http://www.928gt.com/928specs/85-86relay.htm

Ground Points:

Note: Brown wires are solid grounds.
Brown/white wires are switched grounds.

There is a ground, and various connectors beneath the plastic cover, in the spare wheel compartment, above and forward of the battery. Thoroughly clean and coat all of these to help with starting problems. Of course the battery terminals and the bunch of wires attached must be clean, coated, and tight.

2 engine ground cables attached at coil brackets:
- Right side cable goes from coil bracket bolt to topmost front timing belt cover bolt.
- Left side connects at bottom rear of back timing belt cover.

There are a total of 7 ground points. Some easy to get to others you will need to lift the car and climb under. I will try and get you in the right area.
1) Battery negative pole to body in the trunk.
2) Two points separate points above the central electric board.
3) Engine ground to body on right side member. (about a foot forward of firewall, and a foot deep on right hand fender well)
4) Ground point on front left cross member.
5) Ground point on front right cross member.
6) Ground point underneath instrument panel next to steering column.
7) Ground point in trunk at rear right underneath trim panel. (you have to remove the trim panel for access)
This was taken from the shop books.

Listed as follows in the manual:
-Battery negative to body
-Above and behind central electrical panel (2 points)
-Engine to body (under passenger's side)
-Left front cross member (to left of headlight motor)
-Right front cross member (passenger's side)
-Under instrument panel by steering column
-Under right rear side trim panel (inside)
Additionally, my fuel injection harness is grounded to bolts on the passenger's side valve cover.
'83 US 928S 5sp


https://rennlist.com/forums/showthre...5&pagenumber=2

Ground Point 79 - 83
I'm doing a page on the Factory Ground Points for the 1979 -up 928.

From 79 - 83 they are listed as:

# 1 on front lock member, right.
# 2 at rear of wheel arch underneath right rear trim panel.
# 3 on steering console.*
# 4 on front lock member, left.
# 5 on upper mounting for fuse/relay board*

mulik51

WOW! That's a lot of grounds. Te car ECU unit in the front passenger compartment. There is A LOT OF wires coming to it frm the engine compartment. But there is only three coming to fuse panel, two of them are blue. It looks like main configuration of the fuse panel is 1979,(XX and XIX relays are apart. What about relays, for which I can use a multipurpose ones?

mulik51

ViribusUnits
What milage does your car have?
My e-mail is:mulik4@yandex.ru
If you have any pictures, can you send them to me?
Tanks.

mulik51

Hey, guys!
Remember those three wires coming from engine bay? I think I found out where two of them go. Two wires are blue. There is a small thing, like temperature sensor near Temperature Sensor II. It has no wires connected to it. There is a bunch of wires coming to the engine, near this temperature thing, and two of them are cut. These two are blue wires, the same ones as near the Fuse plate. So, I just connected them to this temperature thing. The other wire is brown, and I didn't found out where it goes yet. The hope is not lost yet. Gotto get the fuses and relays(cannot check anything without them)

ViribusUnits

Brown is a ground. Brown with a white stripe is a switched ground.

Does your tempreture gauge in the dash work? If your talking about the think I think your talking about, that tempreture sensor would be the one for the dash guage. According to the WSMs for the 79, the tempresture sender for the dash guage uses two wires, one is blue with a yellow stripe, the other is blue with a green stripe. The same go for the guage on the 83 model.

This should not effect the ability of the car to run.

mulik51

There is no spark on the spark plugs, but there is the spark from coil to distributor. But it is really small spark. I checked the wires from distributor to the spark plugs, the resistance is .273 Ohms. Should I change the wires? Can the computer or any relay actualy relate to the distributor?
Thanks

kennen

Same thing happened to my '85. Turned out to be the fuel computer relay.

mulik51

Hey, I checked a lot of stuff and got lost in one place. First, I have good healthy spark, so there is no problem with that. Second, I found the ignition relay disconected, (becouse it shouldn't be there), so I connected it (t85-ground, t86-t15 fuel pump relay, t87- to injectors and ECU, t30- to positive battery). So, I got the voltage on the injectors. I heard that one wire to injectors should constantly bring 12V and other should go to the ECU, and ECU will ground it. So, one wire should be powered and another should not. But I have 12V on both of the wires, and interesting fact is that resistance between them is zero. Can somebody tell me should there be voltage on both of them or only on one and what should be the resistance beween them?
Thanks a lot,

Klim

mulik51

Yes, if interested, I have 1979 engine(M3) with transformtaion done to it(from K-jet to L-jet). I checked the number.