Misfire! Advice needed.

[reflexuk]

Last night the Grape developed a misfire. It seemed to coincide with a fill-up of fuel though I can't be certain. The misfire is in cylinder 3. I removed spark leads until the engine note didn't change at tickover. Then I pulled that spark plug, looks fine, put it back in the lead and rested it on the rocker cover to see if it had sparks. It does! I swapped the plugs around a bit, all look brown. Multimeter to hand so checked the lead, it has the correct resistance. Now I don't know where to look next! I have to drive 90 miles in it in about an hour. I'm not looking fwd to it..

Any advice/ suggestion?

 

[frank]

swap injectors over maybe wayne ?

 

[reflexuk]

Injector screws are a pain to get undone the first time aren't they Frank? It did cross my mind it may be blocked. Though the tank wasn't too empty when I filled it yesterday I ran it quite low on Saturday morning, I've done the same before and it didn't seem to suffer. It will have to wait until later on now I think.

 

[frank]

yes mate, i usually "crack" the screws 1st with some molegrips

 

[SuperUno]

You may have left now but.... try unpluging each injector in turn like with the HT leads to see if this makes a difference. I traced a faulty 'black' injector like this. And yes the first 'crack' is hard, i splashed out and got some expensive mole grips and then it was easy. I replaced the screws with some better allen bolts.

 

[reflexuk]

Well , we struggled along the M56 , through Stockport, up the chapel bypass (using loads of fuel) then onto a long steep 2nd gear hill. Holding 4krpm 33mph it suddenly cleared! Drove the last 30mile normally. Do we think a new fuel filter should be fitted?

 

[reflexuk]

T

You may have left now but.... try unpluging each injector in turn like with the HT leads to see if this makes a difference. I traced a faulty 'black' injector like this. And yes the first 'crack' is hard, i splashed out and got some expensive mole grips and then it was easy. I replaced the screws with some better allen bolts.

Pulled injector plugs before I set off. Found the same results, it didn't miss not having no3.

 

[SuperUno]

Sounds like a blocked injector then, time for a new fuel filter.

 

[1275]

Amazing the effect The Wanted Inn has on cars