Check engine light on corrigations

[HankyBoii]

Hey guys I've got a ZD30 series 3 patrol wagon and I keep getting the check engine light on the dash. I'm currently on my way up to Cape York, so as you can imagine, roads are pretty rough.

It only comes on after quite a bit of driving (2-3 hours) and typically on corrugated roads. Its not super consistent, but comes on when we're travelling between 60 - 80kmh.

When the check engine light comes on it reduces power and doesn't let me rev past 2000rpm.

If I shut the car off and turn it back on again, it goes away and usually takes 20-30 mins to come back on.

Things I've tried so far:
- Clean MAF
- Disconnect sensor at the base of fuel hand pump
- Filled up with fresh new fuel

Any ideas? Wish I had a scan tool with me 😅

[Brissieboy]

Scan it and see what codes show, otherwise you are just working blind.

[mudnut]

SCA or maybe autobarn, places like that sometimes let you scan the vehicle. Ring first and confirm, also lets them charge the unit before you get there.

[HankyBoii]

Got it scanned today

Code 77
P7-F INJ TIMG FB

Does that mean anything to you?

[mudnut]

Google search indicates fuel problems. Air in fuel, clogged filter wiring harness etc.

[HankyBoii]

I've done so many things but can't figure it out.

I've replaced fuel lines, replaced fuel filter, cleaned MAF, cleaned MAP sensor, checked for boost leaks / loose lines, took every connector apart and sprayed with contact cleaner etc..

Funny thing was I lost revs on the Tacho for a day or two but then it came back. I thought it may have been the crank angle sensor, but mechanic says it's fine.

Could this be a failing pump? Bad wiring? A sensor issue?

Any help would be great!

[jay see]

Injectors?

Sent from my Pixel 7 using Tapatalk

[Coldcomfort]

My old 2006 GU used to do the same thing. I was told its just the fuel in the filter getting shaken and aerated.... I never had any other issue.... From memory there is a fuel drain button on the Di ? That used to make it go away for a while.

[HankyBoii]

I put a fuel system cleaner in my fuel and it has seemed to solve the check engine light problem. Would you still recommend getting the injectors replaced?

Just wondering if the issue is now fixed with the cleaner, or will it happen again?

[mudski]

I put a fuel system cleaner in my fuel and it has seemed to solve the check engine light problem. Would you still recommend getting the injectors replaced?

Just wondering if the issue is now fixed with the cleaner, or will it happen again?

Well if the fuel treatment worked, i would say you probably had a small amount of moisture in the fuel filter and the WIF sensor was going off. Water is heavier than fuel so it sinks to the bottom of your filter, and any fuel will simply pass over the top of the water in the filter. The WIF sensor is simply a slide mechanism with a float and the reasoning i think for the light intermittently going of is the was only a small amount of water in the filter, probably sitting just below the switch point on the sensor, and hitting bumpy roads is just enough to excite the sensor.

Will you need to replace the injectors? Depending on how many k's they are really. Your filter has done its job of protecting the pump and injectors so i highly doubt there will be damage. It certainly won;t be bad to replace them if you feel the need too. You could get them tested to see the condition of them if you like also.

So as of now, change the fuel filter out and keep a spare, and maybe dose the tank on the next fill. Diesel conditioner is very good at dispersing water and algae.