High Idle @ Cold Start (~3k)

Ok so I noticed that when I fuel up, well when I remove the gas cap, there seems to be a huge amount of pressure built up in the tank. It blows off more than any vehicle I've ever had. Could that be part of the high idle issue? Like excess pressure in the fuel system? If so what would cause this/ or how could I fix it?

my b2200 does this too kinda scared me i donno what causes this i just open the cap slowly i think its because of the gas cap i thought i read somewhere not sure if it is ima get a new one asap mine is still OG

Another weird thing I've noticed is that my headlights actually get brighter when I shut the truck off. That is to say that when the motor is running something seems to be putting a big draw on the electrical system. Could that cause any idling issues?

bump? ? ? anyone please? this thing is my daily and I could use some input

sounds like a short. mine get brighter after i tap the gas. and stay that way after it revs back down. see if your alt wires were spliced and replaced to fit your alt. if somone changed the harness, they may have done it backwards or used the wrong alt. if that aint it, id be stumped too. lol good luck.

Doubtful it's related to or causing your idle problem.

Check the battery voltage with engine off. The check system voltage with the engine running. Probably one of the following -


1. Bad Alternator / Diode
2. Bad wiring associated with the alternator
3. Something else shorting or drawing too much current when the truck is running - so something on the Ign 1 Circuit, Ign 2 Circuit, or the Accessory circuit.

Have alternator tested.

Engine running, turn everything off - radio, amps, AC Fan, ect.
Does it make a difference?

How are the lights and voltage with the engine off but he key in ACC Position? On Position?

idk if efi trucks have a choke but if u do, try unplugging it from the back of the alt. not permanantly just to check. r you auto? maybe your bump up idle sensor thinks theres extra load......clueless good luck

I need to check all that.

and no mazdafvr I'm manual. This thing is pissing me off. I just need a new throttle body and all the sensors related to it. Hopefully I can find one in a JY.

I'll get back to you guys. Thanks!

Hey mate where is the IAC Valve located?

Right on the Throttle body. Are you the guy in Australia? If so I don't know if the dual fuel 2.6 is the same as mine.