D-90 occasional missfire around 2000-2500 rpm

[Toddco]

I have a 1995 Defender 90 that will occasional missfire for a split second while cruising around 2000-2500 rpm. It has new spark plugs, wires, O2 sensors, and an ignition module. The ECU is not giving me any codes. Any sugestions?

[rover4x4]

fuel filter did you replace cap and rotor? My D-90 did this sometimes. I dont think it has done it since I replaced fuel filter but I havent really payed attention? Maybe it in my head?

[chrisvonc]

I had/have something just like that and the dealerhsip identified it as a problem with the throttle sensor. There was a whole thread on something just like this on the old BBS.

Here is the link to the most recent one:
http://www.d-90.com/cgi-bin/discus/show.cgi?tpc=16&post=5566#POST5566

Here is another one that might help:
http://www.d-90.com/cgi-bin/discus/show.cgi?tpc=16&post=8561#POST8561

[Toddco]

I recently installed headers and new oxygen sensors to. The ECU was telling me that I had a bad oxygen sensor. I just replaced the TPS with a used one, new one on the way, but still having the same mis. Its sparitic and I can't repeat it, just happens. How did you guys post your pic here?

[Doug]

I have the same symptom, only at 3200 rpm. I replaced o2's, runs much better but still have the bogging only after the engine warms up.

British Pacific just referred me to a guy that has the computer, going to run the diagnostic next week. I'll let u guys know....

Doug

[Doug]

I have the same symptom, only at 3200 rpm. I replaced o2's, runs much better but still have the bogging only after the engine warms up.

British Pacific just referred me to a guy that has the computer, going to run the diagnostic next week. I'll let u guys know....

Doug

[Rick Carlisle]

Todd, you said you recently installed headers? Who/where did you get them? I have looked but can't seem to find any for my 97 sw.
Thanks. Rick

[Toddco]

Summit Racing part# HED-39800

[Toddco]

Any one ever had any problems with there Mass Air Flow Meter?

[vesparover]

Hi todd, I was having the same problem- replaced the alternator and a million other things. Ended up being the power wire to the electric fans I run was grounding out as it had worn through the protective sheath in one part. If you're running any high amperage accesories check all the wiring.
brian bertolini

[rover4x4]

lets hear something about those headers. Are they the ones for the 3.5L RR

[Toddco]

Found the problem, Igintion Module went out agian only 6 months old. I carry Ford black box for a spare this time I'm wiring it in for good! $16.99 vrs. $139.00. The hedders work good but alot of work to install and kiss the cats goodby. The hedders are for the 3.9 HED-39800

[Doug]

Todd, can you explain more about the Ford black box and how that solves the problem in the future?

Thanx:confused

[Toddco]

This is how it is wired:
Distributor wire blue connect to orange wire duraspark box
Distributor wire red connect to violet(purple) wire duraspark box

Red wire from duraspark box to postive key on igintion.
Black wire from duraspark conect to Ground.
Green wire from duraspark conect to negative side of coil.
White wire from duraspark box optional hook up to solenoid wire from starter, for easier starting. Make sure the box is grounded good.
This gives you an alternative to the problamatic Lucas module that Land rover has had problems with from the begining! Land rover uses a variable reluctance magnetic pickup distributor and guess what, so does the Ford duraspark distributor.

Please notice the changes. The Duraspark box fires on the rising edge of the signal. If your Land Rover original box
fired on the falling edge then the polarity will be reversed, meaning blue goes to orange and red goes to violet(purple). Be sure to check timing when finished!

[Doug]

Thx, Todd. BTW I may have found my problem today. Disty is not advancing fully for higher RPMs. Will repair in next 24 hrs and report.....

Doug

[Toddco]

Just added a new vacuum advance unit and all is well! I'm getting 16 mpg running 37"MTR's Thats with the GPS.