Bad Idle - Performance - Transistor or Coils or

[daegrigg]

I've looked at this until I am cross eyed so maybe another set(s) of eyes will help.

Problem: Bad idle, mediocre performance, clear miss at idle but no gas smell

Usual suspects: Done it all, MAF, plugs, pump pressure, timing, injectors.

Look at my plugs: http://mysite.verizon.net/daegrigg1/id1.html

All seem OK except for 2 and 4 which are running rich. (Resistances shown were before injector replacement)

I am thinking power transistor (even though 2 cylinders on that bank are OK.

OR

Coils - producing poor combustion even though two coils going bad adjacent to each other would have to be rare.

OR

(Connections?) - Your "eyes" appreciated. Don

[maxnix]

Problem: Bad idle, mediocre performance, clear miss at idle but no gas smell

Usual suspects: Done it all, MAF, plugs, pump pressure, timing, injectors.

Intake manifold cleaning? EGR valve? IAC Valve? BG44K Fuel filter? O2 sensors?

Can you move the coils (one at a time) around to a different cylinder?

[1990Q45'r]

Manual shows how to check coil packs and transistor ignitors with ohm meter. #2 and #4 not firing properly.

[Q451990]

Did you replace the plugs after your injector replacement? In both of my injector failures, the corresponding plug was badly fouled (like your #4 and #2 plugs. I was able to clean the plugs well enough to get everything firing again by brushing them with gasoline and a toothbrush.

Also, are those Bosch plugs? If so, this is a great time to replace them with OEM plugs! Bosch plugs are known to loose electrodes on the Q.

Heath

[maxnix]

Also, are those Bosch plugs? If so, this is a great time to replace them with OEM plugs! Bosch plugs are known to lose electrodes on the Q.

Heath

Bosch!!! Aaaacccck! Replace all now with OEM NGK! Known to kill many a VH engine.

Good eye Heath!

[daegrigg]

Yes, I did replace these plugs with the correct NGK. I will look for the test in the FSM, maybe just get some replacement coils and R/R.

Thanks

Don

[maxnix]

On the VH41DE some interchange. Better to diagnose than buy expensive new ones or questionable used ones.