dogleg

had my 81 euro on a diagnostic machine the other day i had a connection to the coil lead and exhaust prob for pulse,at idle it detected a misfire on 2,4,5,and7 with 1,3,6,and 8 being ok.also passed a smoke test on the intake system.i have recently fitted new plugs,ht leads,fuel and air filter.i,m fairly sure my problem is bad or semi blocked or leaking injectors on the misfiring cylinders and have ordered a set from AZ i,m currently awaiting delivery.i,m a little worried about the uniformity of the misfiring cylinders?every other one!is there any common denominator between these two sets of cylinders ?any suggestions greatly appreciated......................

Dennis Wilson

Have you checked the distributor cap for arcing, cracks or corroded posts?

Dennis

dogleg

yes had checked it, it looks perfect i would have changed with the plugs and leads if i thought it looked suspect.

Dennis Wilson

How about the green wire? They can loose their shielding and cause intermittant firing or the plug end near the jump post can get corroded.

Dennis

pcar928fan

Have you done a T-belt recently? Might be a mis-timed cam on that side... My GTS when the timing was off popped and burbled and made no power and didn't want to idle right...

dogleg

belt is next on the list of things to do after i sort
the missfire,car runs perfect with good horsepower and smooth as silk above 2k rpms its only small trottle openings that this raises its ugly head.i think its most likely injectors ive sourcede them at €18 new each so be nice to have new ones in there even if it doesent sort the missfire.

Dennis Wilson

James,

Good idea about checking the cam timing but the bad cylinders don't correspond to a single cam. Wouldn't hurt to check it anyway.

Dennis

Dennis Wilson

If your distributor has both advance and retard vacuum connections, make sure they aren't reversed.

Dennis

dogleg

only has advance and i,ve checked it works fine

LT Texan

are you getting spark on those cylinders?

I'd replace the distributor cap and rotor no matter the visual condition.

SteveG

"it looks perfect"

You did remove the dist cap and look inside, right?

LT Texan

spark plug wires to the right cylinders?


4 8
3 7
2 6
1 5

dogleg

you may prove to be right on that one
yes cleaned up the rotor and had a very close look at the cap inside and out!

dogleg

had not used the car to work today as i,ve decided to sort this running issue before using it again.so got home from work this evening and removed no 5 injector and no 2 injector which are on the suspect misfire cylinders,both came out easy but both have a huge build up of gritty black dirt all over the body of the injector the nozzle looks fairly clean in comparison is this normal?going to remove 4 and 7 tomorrow in preparation for my ups delivery of new injectors early next week i hope.sorry for lack of pics will try to get some up soon.tks for all the help.

LT Texan

I think that is odd.

Bad seal. Major vacuum leak?