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Discussion Starter · #1 ·
I have a problem with my 84 30

I have a problem with my 84 308qv that I have been fighting for 2 weeks. I must be overlooking something.
Filled with fuel, as I pulled off freeway after 200 miles, starting missing badly, backfiring and very reluctant to rev up.
Things I checked:
FV is buzzing, safety relay by FI ECU seems to operating properly, both coils seem to have consistent spark when looking with timing light.
CIS pressures were about 10 lbs high, cold & hot (37/58)
Drained fuel, checked sock filter in tank, replaced external Bosch filter, replaced fuel, pressures now seem to be OK (27/48), holds pressure fine after shut off (no leaking injectors?), removed FV and related regulator, all lines/connections were clean.
Removed both dist cap & wire assemblies, pruned back wires a little, reinstalled in cap, hooked up ohm meter, no ohm change when wiggling wires. 2 extenders looked slightly suspect, replaced them with spares that looked(?) fine, replaced BP7ES’s. Rotors or caps don’t show any arcing or carbon tracks.
Unplugging, grounding or putting 1.5v on green O2 sensor wire to fi computer seems to make no difference, green wire has continuity to fi computer. O2 sensor does have 0 to .9v with it reluctantly revs up.

It ran like this once before, at that time it was the fi safety relay not closing electrically and the FV was not buzzing. Had to clean the points in the relay and was working fine.
I have previously added ground wires to digi’s, fi computer, coils and to the motor itself.

This isn’t like dropping 4 cylinders, it seems like it’s lean on all cylinders with popping back thru the intake.

This thing has me baffled, any knowledgeable suggestions appreciated.
I read of someone that had a bad relay in passengers compartment???

Thanks in advance….Larry Fremont, California

Discussion Starter · #2 ·
It does sound like the Relay,

It does sound like the Relay, pull off the top & make sure the positive lead isn't burned thru on the inside. The O2 Computer controls more than just the FV, it also controls the TPS. Also the O2 Computer wiring can get loose or moisture from the antenae hole.

Discussion Starter · #3 ·
Assuming O2 computer & FI

Assuming O2 computer & FI computer are the same thing.
Everything is neet & clean in that area of my car. FI relay clicks over when plugged in, engine running. Both ground signals from TPS are making it to FI computer plug.
Any other suggestions?
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