Nic Posted September 27, 2009 Share Posted September 27, 2009 Unlikely with a Cat still in... poor Walbro fitment could cause lean running. The FCD is also a possibility as they're wired into the MAP sensor signal to the ECU - it could be feeding duff information to the ECU causing not enough fuel to be injected as this is the signal the ECU uses to calculate how much fuel to inject. The fact that you mention a hunting idle also suggests FCD - I had a couple of duff THOR units that caused the same. Was the idle OK before FCD fitted? Cheers, Brian. Yeah I was thinking exactly the same, if it's never run right since the the FCD and pump were fitted, then those would be the first things I'd suspect. I'd refit stock pump, rewire the FCD and then check the AFR's. Quote Link to comment Share on other sites More sharing options...
Nic Posted September 27, 2009 Share Posted September 27, 2009 Just another thought, is the car fitted with a standard Toyota ECU? Double check there are no Japanese branded stickers on it. Quote Link to comment Share on other sites More sharing options...
tDR Posted September 27, 2009 Share Posted September 27, 2009 I'd refit stock pump, rewire the FCD and then check the AFR's. Agree on the refit stock pump but removal of the FCD will mean fuel cut above 1bar when on full throttle for sustained periods. Just thought the boost doesn't even add up - I'd be very surprised if you were able to hit 1.2bar with a cat still in place, you shouldn't need a restrictor ring in the exhaust if you still have a cat. Do you have a decent boost gauge on it? What model FCD is it? Some of them are extremely naff in that they scale the voltage (MAP sensor sends a 0v - 5v signal out to the ECU) all the time such that if the MAP sensor sends 2.2v for say 0.5bar boost, the FCD intercepts this and sends 2v instead meaning less fuel gets injected as the ECU thinks you're making less boost than you are. What you want is one that 'clamps' the voltage such that only a modified signal is sent to the ECU above fuel cut threshold (1bar boost / 4.5v), with the GReddy for example you can set it to clamp at 4.45v / 0.98bar boost which is fine as there's plenty overfuelling up top such that 1.2bar is fine with the fuel being supplied for 0.98bar - below the clamp voltage the signal from the MAP sensor is sent through to the ECU so 2.2v = 2.2v such that the usual amount of boost in my example for 0.5bar is injected etc. Also, when fitting an FCD you're best to use a chassis ground (I'm sure we used an eylet soldered on to FCD ground wire then bolted to a hole near the ECU in the passenger footwell in the days I used an FCD before going MAP2) rather than the ECU ground usually suggested in FCD instructions. A poor earth can cause all sorts of problems... Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
DAVE-W- Posted September 27, 2009 Author Share Posted September 27, 2009 There is no boost controller but i have a boost gauge. With rr in gauge reads 1bar and without its approx 1.25(thats with 1st cat out and 2nd still in). On whether the car was lean before parts were fitted i dont know. Basically as soon as the fcd and pump were fitted i took out rr(1.25bar) and took car straight to get fueling checked. Was told it was badly lean on this setup but i hadnt had fueling checked on previous 1bar setup before fcd and pump were fitted so i dont know how it was before. I noticed when the stem seals were getting done that there was alot of oil in head so im starting to wonder if it has been running lean and caused damage to a piston. Ill need to get a leak down test done to confirm this. One other thing that has had me puzzled is wiring inside engine bay which is white and has "FET Tuning System" printed on it. All the connectors from this wiring are just lying loose doing nothing. Going to just bite the bullet and get the fuelling/boost etc checked on rollers at AVA and just hope they know what their doin Cheers Dave Quote Link to comment Share on other sites More sharing options...
Nic Posted September 27, 2009 Share Posted September 27, 2009 One other thing that has had me puzzled is wiring inside engine bay which is white and has "FET Tuning System" printed on it. FET is a Japanese car accessory brand. http://fet-japan.co.jp/brands/index.html#fetdds Quote Link to comment Share on other sites More sharing options...
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