93 V6 4runner problem

[Barney7779]

Ok guys need some help here

Mate of mine a a 93 V6 4runner, When it is cold it runs perfect but as soon as it get to operating temp it wont idle, has no power and is blowing heaps of fuel out the exhaust

The change from running good to running carp is instant and is not something that gets worse as it gets warmer. If you turn it off and let it cool for 10 mins it starts and runs fine until it gets back up to temp then it runs bad

Things we have changed/tested so far

Air flow meter(replaced)
Coolant temp sensor for ECU(replaced)
Plugs(replaced)
Plug leads(tested all good)
ECU(replaced with a known good unit)
Coil/igniter(tested good)
TPS(tested good)
O2 sensor(tested good)
Timing(checked and correct)
Dizzy/rotor button(checked all looks good)
All vacume hoses connected and in correct position
Fuel pressure Reg(replaced)
Fuel pressure checked(all good)


The computer will not show any error codes at all

What else could be causing the problem

Need some help guys or it will be BBQ time for the 4runner

Sorry for the long post but we are both out of ideas as to what it could be

Thanks

[ratboy]

check the comp cold then hot

[Sic Lux]

Maybe see if you can get a efi specialest to look at it all th4es things at work we do sort out most of the dramas but there are ones that are a pain in the ass so insted of waisting time we just call a guy in and he gets them sorted DTC are one thing but you can get heaps more out of a scan tool than just that depends of knowlage of operator and from what the guy that does our efi stuff knows it a leage above what most people can do with a scan tool.

[Sic Lux]

Another thought get injectors flow tested and cleaned.

[fj45iris]

maybe fuel vaporization, fuel line to close to exhaust or something heating it excessively

or maybe vacuum leak, when hot a crack in manifold for example might open up and loose vacuum causing it not to idle
sorry will have to be trial and error on a few things cos so many options

[Barney7779]

Thanks for the tips guys

Changed the fuel pump today as it was the only thing we hadn't changed so thought stuff it may as well


All seems fine took it out for a good run and had no problems at all


Thanks again

[Yumsylux]

why would a fuel pump run rough when it's hot? That's just bizzare. Anyone please explain?

[Sic Lux]

Welcome to the world of mechanics could be something to do with the springs inside the pump when heated up lose there "springyness" asuming it's mechanical, eletrical could be build up of heat from current flow which creates greater resitance then you have lower voltages just a thought.