Re: Problem with 75 TS

[Anders Nilsson <anders.nilsson@domain.elided>]

jonathan coates wrote:
> 
> Hope your car is getting better, if not, what did you try so far?
> --
> jonathan coates

Short answer is:
NOT :-(

Long answer:

Symptoms:
I have seen (with a timing lamp) that it is missing sparks. Occasional sparks at
lower revs, just enough to see the lamp flicker, and the engine hesitating. When
revs rise to >2000rpm (or sometimes 4000rpm) the sparks are out completely until
revs are down below the limit again. I've checked on various plug wires, with
one or two coils in action and on the coil-to-dist wire. It seems as it misses
the sparks of a complete revolution(sp?) and not just for one plug at a time.
When the engine dies, there is no spark whatsoever to any of the plugs, which
make me think that the problem is not something around the coils/dists.

Checked things:
Resistances in the coils are ok.
No voltage drop from battery to coils.
Infamous 5 lead switch and relays checked and cleaned.
idle switch checked.
AFM checked.
Crank sensor has ok resistance and does give a voltage signal when the crank
turns. Only measured with a volt meter, I'll try to borrow an oscilloscope
tomorrow to measure the actual signal.
Then I'll also try to measure the ignition pulse signal from ECU to coils.

My potential culprits are now down to two; crank sensor missing the missing
tooth, or (God forbid) the ECU itself.

More hints anyone?

Regards,
Anders Nilsson
- -90 75 2.0TS

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