Landseer

Update.

Last night I took the fricken interior apart to get to the right quarter ground. It was corroded pretty well. Fixed.

This morning I snatched a crankshaft position sensor from a 944 in the driveway.

Installed into the 928. Started and revved instantly, no clicking.

Now, I've been here before. Too early to proclaim victory. But very promising!!!!

So, prelimilarily, a bad CPS was causing bad rpm signal (intermittent failure). It was somehow causing the LH relay to cycle at a rate of something like 3 or 4 clicks per second? Wild, if true.

The starter always worked, no matter what, if trans was in N or P, so I think the ground clean effort was good, but not central to the solution. Needed to be done.

Mrmerlin

FYI to get to the hatch ground , remove the rear right tie down at the rear edge of the interior quarter panel floor, then remove the 3 or 4 screws that anchor it to the rear and to the floor, carefully bend the rear edge out so you slide a 10mm wrench onto the floor of the hatch and clean the connection should take about 40 mins

FYI #2 my 84 Euro was also doing the multi clicking relay dance till I cleaned the rear ground connector, glad your running

Landseer

Ha! So maybe THAT solved it. Same systems on Euro and this. Thanks!
(in a knock-on-wood kind of way).

Will try it on the road as soon as these showers clear away here.

Mrmerlin

dont forget the hot post cover

Landseer

Not solved. Maybe narrowed-down.

I changed the CPS, cleaned the back right quarter ground, the ground near the CPS, and looked behind the CE panel, leaning it forward without unplugging the plugs.

I had to manipulate the MAF connector.

Ran it about fifty miles. It burped a couple times under heavy throttle near 5 k rpm, almost like a bubble of water in the gas. For the most part it ran great, very fast and powerful like our 86. Put a bottle of Techron into the tank w/ about 6 gallons of gas, ran it, filled the tank with hi test from a high volume Sheetz gas station.

Last night I moved the car into the garage. It took a couple tries to start it, and the LH relay began stuttering fast again.

I think there is a hidden short. Gotta find it. Gonna trace wires, pull boots, compare voltages on on the key relays with the 86 car. Speculating, but I bet this is why the original owner parked it. I'll find it. Might put the 85 CE into the 86 car

Shark Attack

I had this exact same thing. It was the small wire on the + post of the battery was loose. I leanred that little wire runs the ECU and it made the relay chatter.

Landseer

Thanks, Kyle. Will check. Its this kind of thing that's happening to this car somehow.

JHowell37

I vaguely recall that wire giving me **** a time or two a while back.

Shark Attack

I PO'd the tow truck driver, As soon as he pulled up I was hopping in to start it up. I remembered I was in the battery compartment that day and I saw it was loose and wiggled it. Then I remember I never tightened it up.... Low and behold that was the issue and it sounded EXACLTY like your issue.

Good Luck. Lettuce know

mark kibort

you asked about the jumper for the alarm system. its the red/black wire and yellow wire on the wire connectors at the bottom of the fuse panel. I think connector B and F, but Ill double check that.

Landseer

CE panel out again.

Picked through the wires and found no melts or disconnects.

W-plug is on the right end of the panel. Its here that the mice enjoyed peeing. So I took a lot of time cleaning the panel electrodes here again. So this is a reasonable suspect for an intermittent short.

Red wire was tight and clean on the battery. I'm planning to strip the insulation back a bit just to inspect for hidden corrosion. What route does this red wire take beneath the car? Anybody know physically where it enters the harness for the brains?

Landseer

Thanks to all that helped me. Frustration was about to win.

MP VIII had a bad connection between wires and ring terminal. This ground is located at the back passenger side of the block, approximately under the heater valve. I clearly hadn't cleaned it very well to start with and I left it somewhat loose. Somebody else might have messed with it before, it seems, and shrink wrap covered-up the problem.

This ground has 6 brown wires. The wires have big roles:
EZF box ground, pin 1
LH box ground, pin 5
O2 sensor ground
MAF ground terminal 4
TPS ground terminal 1
85/6 Test connector ground terminal C

No wonder I had weird intermittant running.
Not catching this earlier was a mistake in troubleshooting.
Live and learn.

(Also, thanks Mark, you are right about the alarm bypass. It can be bypassed at the flat 8 pin plug behind the CE panel, or, at the alarm box itself. If anybody needs more info on this, send a PM)

Here are a few pictures:

SeanR

Just reading through this thread, my first thought was that ground at the bracket, the exact one you just found.

Glad it worked out.

Jadz928

Wow Chris! I'm really impressed how you stuck with it and found the culprit.

I really hope your are sitting back, drinking a glass of wine, swimming in victory and grape.

Landseer

Gotta go to FoodLion store now for some Cab and lottery tickets.

What a long two weeks of hell. Intake job, TB job and this witch hunt.

This has been the electical corrosion machine. If you still have that ground wire picture from Frenzy 13 you should post it up!