[franku]

Hi all,

I have searched these forums - wow there is an incredible amount of knowledge here and wanted to see if anyone can share some experience that might help me resolve a problem which has been bugging me for quite a while now.

I have an 80 series GXL wagon(4.5L Twin Cam Petrol) 1993 model with 128,000K's (80,000 Miles) on the clock.

For over a year now, it has lost power between 2 and 3,000 revs, more obviously when it is cold but it is still there when the engine is at full temp.

It is also more obvious when I am towing my jetski or boat.

This is mostly noticeable at about half pedal. When the pedal is fully down, I don't seem to notice it, but I am finding myself accelerating harder to compensate especially when towing.

When the Tacho hits 3,000 I can feel the power come on at half pedal.

Also, when it is stone cold, as I accelerate at 1/4 to 1/2 pedal - it gets to 1500 revs and hesitates and then you feel the power come back on - a few minutes later it wont do it. If you start the engine hot, it wont do it again until it has been left for many hours.



At the last service, the mechanics did what they called a top end clean(they sprayed some "magic stuff" into an intake somewhere as I understand it) to clean carbon out of the engine and the engine was a lot smoother when I got it back. It seemed to "hide" the loss of power somewhat but it was still there - I think it is back to the way it was now(8,000k's later).

I have noticed a small split in the pcv hose which is on the left looking at the firewall from the front of the car causing a slight oil leak. I will have this replaced at the service next week(Monday it goes in).

I don't seem to have an EGR(Did the Australian models not have them?) so I am not sure if the wiring harness could be the problem??

I have asked for the Injectors to be removed and cleaned at the service next week although I am not sure that dirty injectors would cause a loss of power mainly when it is cold???

I have run fuel injector cleaner through it several times - it seems to run a little better whilst it is in the fuel tank and then return after the next fill.

Fuel Consumption around town is 12MPG - 15 on LONG highway trips.

Is 12 about right? I don't give it a hard time really - I think I drive it quite softly in general.

I have run the vehicle on the most expensive high octane fuel in Australia sine Brand new. I run it on this not for the high octane but because it is the best quality fuel and has the best cleaning agents of any other fuel in the country - so I would be surprised it is in fact dirty injectors.

Could my fuel pump relay be the problem? Should I get the mechanics to replace this ?

Does anyone have any idea's at all on what I should get the mechanics to particularly do for me on Monday to help resolve this issue?

The car is 100% orginal Genuine parts except an airfilter which is a foam one which is oiled - only warranty claim has been a rear engine seal(I don't think it needed it - I bvelieve the toyota dealer mistook rusproofing for oil at 80K service just as it wascoming out of warranty - even they admitted that and a new tail shaft because they didn't grease it properly at service). Other than all my accessories and a new exhaust pipe, it is original.

I presume a new non-genuine exhaust would cause a car to lose power and hesitate?

Could I have a faulty air flow meter? I have been told on Porsches that the oil base foam air filters can allow oil to sometimes get inside the airflow meter and this can cause weird problems. Has anyone experienced this?

I am really fussy and look after it really well (it has low mileage for it's age) and it really disappoints me to drive it like this....

I would really appreciate any help possible...

[ssbob]

I know that sometimes the oil from the performance filters can sometimes spray up into the sensors along the intake, most everyone here recommends using the stock air filter.

You may want to remove the oiled filter, clean out the throttle body and sensors (with appropriate cleaners) and put a stock filter in and see if that helps.

Just a thought.

[franku]

ssbob - Yes, I will be going back to the stock Toyota Airfilter just in case that has caused a problem with the airflow meter.

Does anyone else have any idea's?

[franku]

Any other idea's guys?

[landtank]

you might try cleaning the fuel pump relay. It starts out on the low side but at some point switches over to the high side so the pump sees more voltage.

There are a few threads describing how to do this. I would avoid using sand paper as one suggests as this could damage the contacts, severely shortening their life. A new striker form a book of matches is the best option if the proper tool is unavailable.

[franku]

Hi Landtank,

Just relised I never followed up on this - I thought better late than never

I cleaned the contacts on the fuel pump relay very carefuly - didn't improve.

It went in for a service and had the injectors removed and cleaned - I asked them to replace the fuel pump relay anyway - they didn't saying - they never go on japenese cars - if it was a Jag - yes, but no way on a Toyota...

When I got it back mild improvement - probably from the injector clean but still doing it.

3 days later, I am driving the car and it would litteraly lose ALL power if I pushed the pedal further than half way.

I took it back - told them to eplace the fuel pump relay - I was positive this is what it would be - hey didn't believe me.

4 hours later - they rang me and said "it was the fuel pump relay"

Thanks again for your help - I only came to this from reading this forum.

[alia176]

Thanks for following up on the thread...as they say, "closure" can be a good thing! Enjoy your new found performance!