BC

Also to add evidence, the shifts get very hard when it starts doing this.

So I was thinking of checking the vacuum as hot as I can get it. Just as you suggest.

BC

Btw - hot the ohms for the temp sensor which I feel has been related were 245

At the lh

69gaugeman

Guess I got nothing, then

BC

Well, its all open to speculation at this point. I have not done a point to point test on every single wire of every single quadrant of the operational items on the car.

I have used the hammer - but it is not giving me much except that when warm and cold, everything seems fine to it - except of course it said the EZK was bad. Or maybe the wiring was bad. I don't know.

The vac/compression test which was discussed pages ago and was brought up again is something I am thinking about. I am not a huge fan of working on a piping hot car, but this one has required it alot.

I am taking it slow and non-stressed because its thrown me for a loop too many times.

The surging (but a hard edged surge) is very interesting because would indicate electrical. But I suppose it could still be mechanical.

Rob Edwards

Did you ohm the new coils when they were installed? There are 2 flavors of coils, '85 to '88 and '89 to '95- No idea what the difference is but I wonder whether one was a bit gamey right out of the box and is failing intermittently? Might be worth checking primary and secondary resistances on each when cold and when hot?

That said, the hard shifts when symptomatic certainly point towards a vacuum issue and would tie in with the pig-rich-ness.

Starting to smell like we need to have a parking lot intake R&R at SF14. What could possibly go wrong?

G8RB8

If it's not running well vacuum is going to naturally be low as you feed in more throttle trying to get power. Symptom not cause imo.

Bill Ball

Well, if all the part swapping did not change anything, then it would lead me to a harness issue. Error messages with the Spanner/Hammer could provide a clue. You did get a no load signal error as well as others before. Even though the fault may only occur when hot, the code should be stored.

The video did not give me much information other than the car is loud. Colin is smarter than me. I'm not sure where a hot leakdown is going to lead versus a cold one. You seem to be losing a lot more than one cylinder.

BC

It was snapping in and out of bad running today. Enough to move my head, like a turbo kicked in and then turned off. So strange.

Vacuum At idle was 18" or So.

I'm going good to change the ignititors again in idle desperation.

Ducman82

Grounds all good?

BC

Checked as many as I can get to. Twice at the back of the engine.

Today was interesting. Normal, got progressively worse and worse on the way home. I turn it off on the downhill so as to cool it so I can get up the hill without what you see in the first video.

Go to start it - no start. Crank, no start at all. Interesting. Push it to side of the road (These cars are light).

Unplug the temp 2 sensor (which for the record has been replaced and the wires recrimped with a new bosch plug) and the car starts.

Car still doggy on the rest of the way home but I get home.

The Patman

Not because I'm certain that his has anything to do with it, but we have seen something like this before and maybe it will spark a train of thought amongst you more experienced guys that will lead to this problem's logical conclusion...maybe...maybe not.
I've seen a slightly stretched timing belt, perhaps a half tooth off, or otherwise misaligned cam timing let the exhaust valves open a bit soon allowing "still burning" fuel into the exhaust. Causing problems with the entire fuel injection system. (we assumed this was the cause, (we saw no actual timing belt issue but...) just replaced it and the problem went away. I mentioned this story to the OP, but it was always more of a constant underpowered hot EGT thing. Never like a switch on and off. did make the pipes glow red though!!


But watching the video, and reading more about this I remembered another incident where the shielding on an inductive pickup (crank position sensor) would break down in the heat and caused a similar "on again off again" pattern. Instantly. Like a switch. changed the sensor and fixed the problem. Then later we theorized (cause we never actually saw it) that the shielding may have touched one of the wires when the wires got hot and flexible, or the base and shielding got hot and maybe expanded away from each other or into a wire and in the end, it changed the waveform going out to the ignition system enough to cause the ignition advance to switch back and forth from full advance to no advance. It felt like a switch. The clue? Once in a while it did it in time to big sharp jolts on the road. Off and on. Just like a switch. No promises but maybe it'll make you guys think of somethin' that really is the problem

siscogts

I was suggesting the crank position sensor too.
Knock sensors should give other symptons.
my 0,02 .
Francesco

WallyP

Years ago, J.C.Whitney sold an interesting gadget to mount on your dash. It was a round gauge-like device with eight neon bulbs in a circle. Each bulb was hooked to a spark plug wire. At idle, you could watch the bulbs chase around in a circle; at speed the bulbs were constantly lit. Instant feed-back on misfires.

Would it be worth trying to build one for your problem child? Eight neon bulbs, a few feet of phone hook-up wire, and an insulating board stuck on the rear edge of the hood...

Rob Edwards

siscogts

I think it is one of the most headscratching problem I read here.