TB45 loses throttle response on kick down start

[Huseyn]

Hey guys,
So I own Nissan Patrol 1998 TB45E (gulf-spec), 300.000KMs on the clock. Yesterday here was heat outside (around 32°C), coolant temprature went up to 94.5°C. Then I started to lose throttle response, when I press the gas pedal engine wanted to stall for around 2 second then gains RPM. It was undrivable in traffic jam so I towed it to the service. When arrived, engine and outside temp already was cold (15°C) and engine/throttle response was okay, no problems so far. We checked leads and spark plugs anyway, all was in good condition.
On the way back home it suddenly started to unstable idle and while pressing gas pedal fully to roll, it feels like engine in drowining for 1-2 seconds, rpm drops and gains again(attached video below). This contidition is not happens all the time so it is hard to pinpoint the problem.

Happens in these conditions(not always):
1. Kick down start
2. On rolling speed while RPM is below 2000RPM gas pedal fully depressed.

**after 2000RPM no problem at all, even tried on sand dunes, RPM went up to 4500-4600RPM, no power loss at all.

I don't know if it has any connection with the temprature of outside temprature, I would like to where to start to check.

Thanks for the help guys!


https://www.youtube.com/watch?v=X0yWvQdLtdU

[mudnut]

Do the easy stuff first. Look for an intake manifold leak. Maybe a hose has cracked, or fallen off.

Could also be Throttle position sensor. There are youtube tutorials on how to do this easy thing. If it doesn't work, then look at cleaning the MAF and throttle body with the proper cleaner.

[Huseyn]

Do the easy stuff first. Look for an intake manifold leak. Maybe a hose has cracked, or fallen off.

Could also be Throttle position sensor. There are youtube tutorials on how to do this easy thing. If it doesn't work, then look at cleaning the MAF and throttle body with the proper cleaner.

Thank you for your reply,

I will look for intake manifold leaks and clean MAF and throttle body in all cases.
Is there any measurement to check if TPS have any problems? I see 2 x 3 pin plugs there, maybe using pinout and multimeter to get some numbers?

[mudnut]

Thank you for your reply,

I will look for intake manifold leaks and clean MAF and throttle body in all cases.
Is there any measurement to check if TPS have any problems? I see 2 x 3 pin plugs there, maybe using pinout and multimeter to get some numbers?

C'mon TB45 Gurus. Any other simple thing to check? Apart from a blocked fuel filter or low fuel pressure?

[mudski]

First thing I'd do is replace the fuel filter.

If its only doing this when hot maybe it is a crack or leak in the intake somewhere, as the metal get hot it expands... I had an old XB Ford Falcon back in the day and on hot days this used to cut out and carry on. I found the metal fuel line going to the carby was getting so hot, being next to the exhaust manifold, the fuel was evaporating before it go to the engine.

[Huseyn]

Update***:
Didn't touch anything, just filled up gas tank, problem is gone.
As you can see from the videos, while this problem was happening tank was only 1/4 full. Can fuel pump be the reason(overheating)?

[BrazilianY60]

That is possible indeed.

I once was traveling to my hometown in an ethanol turbo truck I had and maybe some 10 Km from the destination the truck stopped. I thought at the time I ran out of fuel, wouldn't even start. It took the tow truck maybe 1hour to get there, and when the guy was ready to winch me up the tray, I gave it a try and it fired up perfectly, and it was able to drive up the tray on its own power. It turns that I was almost out of fuel indeed, but the fuel submersed electric pump, which relied on fuel to cool, was probably running hot and locked.