power hesitation after driving fd for a while

[ttpower]

Strange one this........

Basically I can drive the car for a while and it\'s perfect, then after some time it will become hesitant to climb up the revs and bog down intermittently. I\'ve noticed also when it does become hesitant it runs lean when above 3k.

If I turn the car off for half hour or so it works perfectly fine.

I\'m thinking maybe my fuel pump, any thoughts??

[boosted]

Could be lots of thing unfortunately....any idea when last had a fuel filter? Fiddly but cheap part to try.

[ttpower]

Put a new one on about a month ago. Strangely it seems to only do it when its been running for a while. Also when it was doing it last night, I filled the tank up and it went away until a while later. Thought maybe the cooled fuel helped until it got hot again.

[boosted]

Fuel pump ? again nice to know a new 1 on.

[ttpower]

Yeah I put on a new fuel filter.

Was a thought the new fuel cooled down the fuel pump which is why it started operating normal again? Just a thought.

[Dragun]

Might be worth having the injectors flow tested? Also things to consider are faulty fpr, hot fuel lines expand could cause a loss of pressure in the fuelling system somehow or a leak when the runner expands? Just shooting ideas mate, hope you sort it.

[ttpower]

Ok will check them things, it just strange it seems to happen when it\'s been running for quite a while

[ttpower]

Fpr is good, fuel line are all braided and no leaks.

[Dragun]

Are you still running a cat pipe? Once it\'s warm does it bog down if you press the accelerator slowly to the floor or is it just when you have an aggressive foot? Have you checked compression when cold and when hot to compare? Replaced ignition leads and sparks? Problem is a lot changes in componenets once they are hot, case of process of elimination, feel for you man.

[ttpower]

No, cats removed. I think it\'s the fuel pump, it does it after an hour of driving or half hour of harsh driving. I\'ve noticed the fuel pump resistor gets very hot too. Is it meant to get hot? I\'m going to get a new fuel pump probably an updated one and going to give the pump a solid 12v. All that crappier in the way like a resistor and relay for different fuel pump speeds is asking trouble anyway

[samoht]

Direct wire of the fuel pump is a common mod, presumably for a reason, so sounds like a good plan.

[Dragun]

Yeah like he said, is try hooking up your fuel pump to a relay see if that cures your problem, when your engine is under load sometimes the voltage can fluctuate at the fuel pump causing poor fuelling. Just do a quick goog search \'connect fuel pump to relay\' and there\'s lots of diagrams showing you how. If not here is a basic quick guide for you. If this does not cure the problem, atleast the mod is in place for your new pump

Ok so you need a 4 Pin Relay.

The terminals are usually numbered 30 85 86 87

30 - wire this direct to battery 12v source
85 - goes to ground, simple enough.
86 - goes to the fuel pump power wire
87 - connect this to the + wire from fuel pump.

86 and 87 are basically the same wire your just splicing them into different pins in the relay, that once activated 86 and 87 bridges to complete the circuit. This way no matter what electrical load the Rex is under, your fuel pump has a constant, uninterrupted voltage. As I said if this does not cure the issue then it\'s still a great modification to have for your new pump hope it sorts it.