tb42e idle rough as guts

[hummer.03]

hey guys new member 1st post
I drive a tb42e 1993 and it runs rough as guts hot or cold the idle will be like its got a very large cam in it but it does not
so far iv done the plugs tappets / valves and filters and still running rough know idea what it could be
still drives fine when ya on the gas though any ideas.
its got a 4 inch stainless snorkel with a big airbox and a 2.5 inch straight threw zorst with extractors no mufflers
been like this for over a year but car is a weekender and drivin maybe once every 3 weeks

[JME_GU]

The first step is to check the error codes on the computer. I think the plug is Nissan Consult, not OBD so you will need to buy/borrow a cable and software. I recently spent about a month troubleshooting rough idling issue, serviced plugs, lead, dissy cap, air and fuel filters, etc. I checked and there were no error codes on the computer, I even used a different fuel pump, changed out air flow meter, throttle position sensor, coil but no luck. In the end it turned out to be a bad EFI computer :(

[threedogs]

Have you checked all the vacuum hoses they may be perished or become dislodged

[hummer.03]

Jme gu cheers for that will look into it theres no vacum leaks that i can see and had a fairly good look over and under will look into getting a nissan consult and will see what happens

[Dhuck]

Welcome to the forum mate.

[mudnut]

Hello, and welcome to the forum. Try spraying a bit of WD40 around the inlet manifold and vacuum components with the engine running. If the engine tone changes it means that the engine has sucked the spray in and is burning it as fuel.

[threedogs]

Jme gu cheers for that will look into it theres no vacum leaks that i can see and had a fairly good look over and under will look into getting a nissan consult and will see what happens

I think some Super Cheap stores can check and erase any errors
Not sure if ECU talk would suit your Patrol maybe Bob would be
able to confirm or deny if ecu talk is suitable.

[Bernas]

Hey guys, I came from Indonesiaand this is also my 1st post. The reason I found this forum, excatly the same problem with my tb42e engine. The iddle is fluctuating and I found the injector #6 is not spraying. I have try to switch between them, and clearly its not the injector problem. It must be cable or sensor or ecu itself. Any body got any experience how to fix this? thanks

[4bye4]

G'day and welcome to the forum mate.

[Bernas]

thank you, looking forward if you have any advise or suggestions...

[JME_GU]

If you have changed swapped injectors and the problem is still occurring then it is likely wiring. Check the plug itself, the pins sometimes become unseated, then trace the wiring back to the computer using a multimeter until you find the break in the wiring.

[Bernas]

Yes injector hve been swapped. Wiring also have been tested from injector to ECU and all ok. When injector bypassed direct with (-) from battery, its spraying. Looks like no signal coming out from ECU for 1 of the injector. Its a frustations, because looks like the input signal for ECU to trigger the output to injectoris come from Cranks Angle Sensor inside distributors, and I do not know how to test it whether its works or no.

[brooks]

Hi & welcome to you & bernas, i had an issue once with a burnt exhaust valve could also be just sticky. if you hold a piece of paper on the exhaust tail it should blow away constantly, if it sucks back onto the pipe possibly a burnt/sticky valve.

[Bernas]

thanks will check it