34p 22p 16p 28p with 89661-50351 EFI 1

[land lexus]

Hi I have my 1uzfe running in my conversion, it is de cat and the mil light operates correctly and goes out correctly

I have had problems as my conversion the wiring does not match diagrams I have.

Could someone tell me if efi 1 fuse (black with yellow tracer) should be ignition fed or permanant live?

with permanant live fuel pump primes and runs breifly after shutdown- but efi relay remains energised

with ignition live to efi 1 the pump runs on crank and vehicle starts.

I'd had some stalling from start - I think it is a sticking idle stepper motor. as it comes and goes.

I'd be grateful for any Ideas please

 

[Zuffen]

As a Moderator I would like to see a little more information in your profile.

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Please go to you Profile and comlete it.

 

[land lexus]

As a Moderator I would like to see a little more information in your profile.

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updated profile

okay so my issue with idle appears that the IACV works flawlessly or it doesn't seem to operate- I think it is electrical not mechanical issue.

I have sealed type valve and have carb cleaned it.

it's frustrating as it starts on throttle but doesn't idle and then other times it runs flawlessly.

 

[gloverman]

This issue is generally a wiring issue And from reading your post it sounds like it is wired wrong. EFI1 is hot at all times. If your EFI relay is staying energised with it like this then look into your wiring some more. Cheers

 

[land lexus]

This issue is generally a wiring issue And from reading your post it sounds like it is wired wrong. EFI1 is hot at all times. If your EFI relay is staying energised with it like this then look into your wiring some more. Cheers

Hi
Since fitting fuel pump resistor the efi relay behaves. the problem I have is all versions of the wiring diagrams I have been able to obtain do not match a 1998 registered lexus which is the 1997 square headlight model- please point me to the correct diagram

Secondly can anyone tell me if the IACV calibrates at ignition on, if it does and sticks could this cause a situation where it will start and work perfectly

Or will behave as if the IACV isn't connected on another start

 

[gloverman]

Sorry I dont know where on the net to find the diagrams for that one. I had to buy most of my good diagrams I have assembled over the years and now sell them. The system should work weather there is a fuel pump resistor or not. Cheers

 

[land lexus]

Sorry I dont know where on the net to find the diagrams for that one. I had to buy most of my good diagrams I have assembled over the years and now sell them. The system should work weather there is a fuel pump resistor or not. Cheers

Hi I have USA wiring diagrams which allegedly the ecu is correct, the downfall is that we have checked untouched wiring and the colour and ecu pin locations are wrong.

I have looked at IACV wiring diagram and plan to test with computer safe circuit tester to see if for some reason the ecu isn't operating valve intermitantly.

Could this also be a bad engine ecu temperature sensor- if so could you point me to the test specification resistances cold and hot.

 

[gloverman]

Im pretty sure I have the correct diagram. I would work on normal NTC sensor readings for the coolant temp. around 3000 ohms cold and around 300 hot. I use the scan tool to check this sort of stuff most of the time. If they are way off this I can look up the exact figures.

Cheers

 

[George_R]

I'd had some stalling from start - I think it is a sticking idle stepper motor. as it comes and goes.

What's your engine from? (ecu p/n# 89661-something => toyodiy.com)

On 1995ish celsiors and crowns ISC is powered from main relay. The relay is operated by ECU so as to let the ISC close to the proper degree after you shut the engine off. Otherwise engine will be hard to restart.

Your first checkout is therefore ISC power. It should remain for ~1-2 seconds after you turn the engine off. If it doesn't , start your search from ECU's MREL pin.

 

[land lexus]

Thanks for the replies my donor car was 1997 ls400 european/uk spec change over year the situation is:-

replaced all ecu capacitors as at least one out of spec and re lacquered board.
cleaned the non serviceable IACV and this has improved.

replaced ecu coolant sensor

earthed red wire that came from body ecu originally.

my vehicle has now successfully past Ministry of Transport test and is running lot better if cold start doesn't improve I will delve further

thanks