Engine sputtering chugging between 2650-3200 rpm

[Heath]

1995 D-90 Symptoms:
Engine sputtering + chugging between 2650-3200 rpm
(in gear and neutral)
(seems to get worse with more electronics (heater fan, lights, wipers....etc)

I have seen quite a few posts on this board about similar issues...

So far I have tested the following
ECU (no codes -- hmm flashes 88 real fast when reseting)
Throttle Position Sensor (seemed real smooth from 0-5 ohms)
Battery has a healthy charge and does not fluctuate when engine is reved (same with alternator -- though that may mean nothing)
All plugs seem to be sparking
I doubt coil, wires... because it is between 2650 and 3200 rpms.
It is not speed related.

Could be:
distributor, ecu, crankshaft sensor, voltage regulator/alternator
I don't know how to properly test this stuff. :confused

Any help would be greatly appreciated.
You tell me and I'll test it.
Thanks in advance...
-H

[Mike Hippert]

Heath, you can get the alt, diodes, and battery tested at most local autoparts store for free (autozone always helps me out).

But, I think your problem may be something else, electronic devices cause EMI (electro magnetic interferance) and EMI from one thing can cause another thing to not work properly. Example: While you are watching TV someone starts to vaccume (your mom or your wife) when she gets close to the TV you see static on the screen this is caused by EMI from the vaccume.

So your problem may be due to noise being generated by the alt and getting onto the ignitoin lines.

[Davis]

I had similar problem at similar RPM and it was the alternator. One of the ziener diodes was leaking AC current into the system at that rpm. Had it fixed, all symtoms went away. Should be easy to at least have checked out.

[vesparover]

i had that problem too, replaced the alternator + ground wire+ ran a straight wire from alternator to battery. No more problems
brian bertolini

[wicks]

DW this may be your issue as well. ?

[Doug]

I had a 20 minute talk with RPI this morning. They agree with Mike Green's diagnosis -- flat camshaft. But also cautioned that a faulty distributor or diodes, plug wires, etc. could be the cause. Since I've been through that last bit, I'm thinking cam. RPI said that ECUs almost never fail. It's the last thing to suspect. Also the compression in the v8 is usually not the case either. So, regarding Heath's issue above, I'd go into the ignition/spark path and look for the problem there first. A good computer test from a shop with proper LR diagnostic equipment will help a lot.

Doug

[wicks]

So what r u going to do about that cam shaft? Get out the x-ray goggles and make sure it's flat I guess before doing anything...

[Heath]

Well, I am going to go and get the alternator checked (hopefully tomorrow). Another thing about this problem... It happened instantly, not gradually; I would think a camshaft getting worn down would happen over a long period of time.
I will let everyone know what happens.

[Doug]

Wicks,

It's more than I have time to worry about at this point. At sea level, it's really not a bother. 4,000 or 5,000 feet and it gets annoying. But there's no harm in driving it, so I'm told.

DW

[Heath]

I had the alternator tested today at Autozone (for free). The machine said bad diode. They have a replacement alternator there Duralast (http://www1.autozone.com/servlet/UiBroker?UseCase=C001&UserAction=performMoreDetail&Parameters=TRUE%7C%7EALTERNATOR%7C%7E%2495.00%7C%7 EDURALAST-IMPORT%7C%7E85+AMP++++++++++++++%7C%7EFALSE%7C%7EF ALSE%7C%7E61482%7C%7E1126%7C%7E14361%7C%7ENONE%7C% 7E%24189.99%7C%7ELAND+ROVER%7C%7EDEFENDER+90%7C%7E 1995%7C%7ELLT%7C%7E11.0%7C%7EEA%7C%7EV) . (bad link)
DURALAST-IMPORT ALTERNATOR for a 1995 LAND ROVER DEFENDER 90
Unit Price: $189.99
Core Value*: $95.00
Part No.: 14361
Weight: 11.0 lbs.
Warranty: LLT
Does anyone have any suggestions for a replacement alternator? My local rebuild shop doesn't want to mess with the M.M. Alternator.
Thanks again for all the help.

[Davis]

I had my alternator rebuilt by Simcor in Boulder. He is a class act. He was recommended by the same person (Charlie) that knew what was wrong with my alternator--I HIGHLY recommend him--I visited his shop and can atest first hand to his skill and competence.

[vesparover]

Don't buy those pos alternators from autozone or advance. They are garbage. I put a 130 amp disco 2 alternator on mine, brand new on ebay for $120! I hear mean green makes a good one too.
good luck
brian bertolini

[Heath]

How do you use a Disco I or II alternator? Is the pulley on the front the same as the D-90? Can you switch the pulley? Can someone let me know how they fit? Or if other rover years will work? Thanks again.

[Rover 33]

It's probably the alternator. They can emit an Electromagnetic field that can interrupt the ignition signal causing loss of spark. Just pull the drive belt off for a quick check. If the miss is eliminated with the alterator not turning that's the problem.

[vesparover]

Dale wennegal sold me a bracket to fit the disco 2 alternator. Give him a try.
brian bertolini