Misfire v8i 3.9

[KiwiSteve]

Hi folks
Being anew member of this site I wonderd if any one has experienced a misfire over 3200rpm when accending gardes with cruise activated.This problem is not apparent if engine is run up in parked situation only when mobile.Have replaced plugs leads and coil all LR Genuine.Any clues apreciated.

KiwiSteve
(97 Disco V8I Auto,2inch lift, 245/ 75/ 16AT's)

[muddymech]

just a wild guess have you checked dizzy for any cracks, thats all more knowledge expended anyone else want a guess

[DEFENDERZOOK]

<span style="color:blue">so what youre saying is...going uphill under load at 3200 rpm you have a misfire....?


are you sure its not fuel starvation....?
what are the symptoms.....it wont rev any higher....?
backfire...?

does it do it if you are not using the cruise control....?</span>

[KiwiSteve]

New fuel pump fitted a couple of months ago also filter renued. No backfire just runs rough as if plugs have fouled assoon as you back off full power restored. It can be provoked into doing it with cruise off if you hold gas pedel on the floor above 3200rpm.It will cotinue to rev out but at much reduced power.Also dizzy replaced along wih leads.

[muddymech]

hi
just couple more ideas, check fuel filter again, is there any water in the fuel, have you changed ht leads

[KiwiSteve]

The leads are new along with dizzy rotor & plugs am on way over to Karkraft @ silverwater to get another fuel filter will see what happens. :arrow:

[KiwiSteve]

Back again changed filter no obvious contamination went for run up m4 and the problem is still the same.Might have to take bull by horns and visit dealer to get codes read to see if its thrown any. :arrow: :!:

[PhilipA]

Er, geez it seems the week for it. This may be the third.

BUT this is a symptom of the dreaded sticking exhaust valve. Mate had exact symptoms. HOT = sticks cooler= frees.
Regards Philip A

[Mudnut]

I had the same problem with my Discovery. Ended up replacing the spark plug leads. Make sure that there is a good connection on the plugs with your new leads. I put extra heavy duty leads on to minimize the chance of it happening again.

Ken

[KiwiSteve]

Thanks for the imput guys have booked car in to have diagnostics run on the dyno to see if thy can replicate on road conditions and see what gives.
Regards Kiwi Steve


Keep on Rovin :!: