MR2 turbo misfire

[GerryB2]

Hi,
I am trying to cure a misfire in a friends M reg MR2. The car revs freely in neutral and
drives fine until the turbo cuts in and then there is a constant missfire until the turbo cuts
out.
The fault codes displayed are 42 43 and 52 which I believe are "no start signal" "knock sensor"
and "vehicle speed sensor".
The speedo is working but seems to be registering half of the actual MPH.
I changed the spark plugs as they were well fouled up but within 5 mins driving they were black
with the tip white as if it was run very lean.

Any ideas would be great
This car is not a daily driver but ran fine for a year after the guy bought it

[cptsideways]

Could well be ecu capacitors leaking, common issue with JZ engines & gives very similar symptoms. Requires pulling the ecu & a close inspection of the ecu board. Can be a cheap fix if thats what it is.

[danjama]

Check on Mr2oc and imoc if any members can lend a ECU for diagnosis (yes really) that's one of the great things about mr2's, the community. I would put my money there as well.

[sparkyhx]

coil pack breakdown - see if you can borrow a known good pack and swap one out - go for a drive, swap another go for a drive until you find the offending one. N.B. this is 200sx experience - don't know if its applies to MR2's.