Misfire that just wont go away
Misfire that just wont go away
Author
Discussion

Nigelbs1

Original Poster:

98 posts

200 months

Saturday 3rd April 2010
quotequote all
My 4.5 Cerb misfires between 1750 and 2000rpm. We have changed the HT leads, Plugs, Coil Packs and Tpots. Havn't changed the lambda Sensors as the laptop seems to show them working properly (switching between 0 & 1.5 volts every few seconds) or the injectors.

We have spent hours setting up the Throttle Linkage and Tpots and no matter what we do we cannot get the adaptives right on idle ie. left bank would be say -2.4 but right bank would be +7.8 and with very little movement on the tpots or throttle linkage and we're talking less than a mm the adaptives would just go all over the place. We have also found we can move the misfire from one bank to the other. One minute left tale pipe singing like it should but the right would be fluffy, little fiddle with the setup and it would reverse, right pipe singing, left pipe fluffy.

Any suggestions would be grately appreciated before I pull all my hair out.

jammy_basturd

29,778 posts

241 months

Saturday 3rd April 2010
quotequote all
Electrics? Might be a dodgy connection on one of the tpots, or on the circuit. In fact now I think about it, you say you can move it from one bank to another. If the ECU doesn't get a reading from one tpot then it will use the other, so this could well be it.

HarryW

16,028 posts

298 months

Saturday 3rd April 2010
quotequote all
Concur, look at the loom wiring in the plug/connectors for the T pots etc. I had similar issue with the loom wiring to the connectors that feed the coil packs that took ages to find after swapping changing coil packs etc.