Check Engine Light & Rev Counter drops out

[BigHorney]

Hi All,

I have a 1995 Isuzu Bighorn 3.1TD, Engine No. 4JG2

Check Engine light comes on intermittently when driving, even @ 100kmh.

With the Check Engine light the Rev Counter drops out altogether and the engine starts pulsing quite a lot - so isn't happy about something, if I come to a stop it can stall due to the pulsing revs

If I turn off the car and start it up again the Rev counter comes back and the Check Engine light dissappears - albiet only for a short time until it happens again.

Issue seems to have crept in since I had a slipping Alternator belt due to a broken Belt tensioner - I feel this could still be related to my issue and maybe needs even more tightening but maybe I'm wrong

Has had me baffled for some time.

[geeves]

is this the electronic or mechanical pump?

[BigHorney]

Not too sure on that one Jeeves, it's has a manual diesel pump located in the engine compartment if that's what you're referring too.

Or maybe you're referring to the cabling from Gearbox to Dashboard for speed/rev regulating.

This model is a 1995 3.1TD

I was trying to replicate the problem and was switching from 2WD to 4WD and then it happened whilst idling and rev counter drops out and the engine starts pulsing up & down by itself.

not sure if I have narrowed it down, I can only see a VSS Vehicle speed sensor underneath connected into the Gearbox, not sure what other gadgets are under there to check

[BigHorney]

Pretty much believe this is due to the slipping belts

[geeves]

My money is on the governor in the diesel pump. 95 could be manual or electronic. Have a look The manual has a cable on the front the electronic a box on the back and no throttle cable. Electronic pumps are known foe governor faults and this is the symptom