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liljlandon

liljlandon

Joined
Feb 21, 2008
Threads
136
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1,608
Location
SW MO, NE OK, and NW AR
Ok... I have wired a toyota EFI system onto an 84 toyota block/head.

I have ran into some problems, some have been fixed... Others not so much.

I immediately pulled codes;

21 - o2
41 - TPS
51 - IDL/TPS
52 - Knock

Engine will start first try and idle strong for ~30 seconds. It will then start running rough and without input, it will die. If you just move the throttle ~1/4" it will smooth out and run perfect. If the TPS is unplugged, it will idle high but run okay otherwise.

Any quick 'blip' of the throttle will result in it dogging. If you don't let off immediately after it dogs, it will backfire through the intake.

So... I went through and adjusted the toyota TPS. I found it had a 'dead' spot in it. Replaced and adjusted per 4crawlers page. Ohms within all Toyota FSM specs.
That got rid of code 41.

I changed the passenger motor mount.
Bye-bye code 52.

I checked, double checked, and triple checked the timing. 5* with terminals shorted.

I thought it may be the AFM. Ohmed out to FSM specs.

I thought it might be a vacuum leak. I took a propane torch and moved it around the intake unlit. No change.

I thought it might be the wiring to the TPS. Wires ohm out to have no resistance.

I thought it might be grounds. I have grounded it so many ways it resembles a motor on life support.

Fuel delivery = great.

I pulled the valve cover and timing chain marks, cylinder, and harmonic balancer marks all check out.

WHAT AM I MISSING?!! Pulling my hair out!
 
What's going on with code 21, if the ECU is not getting a proper air fuel ratio reading from the O2 sensor that could be causing the issue. Any chance you have access to a air fuel reader, the kind that goes in the tail pipe, this will give you an idea if the ECU is trying to compensate for bad O2 readings.

What's the condition of the distributor and or the ignitor, are they correct for the EFI system you installed? Almost sounds as though there is a timing and fuel issue, like the ECU is leaning out too much.
 
On the leaning out - I played around and manually pushed the afm flapper while at idle. The truck runs better. Still hesitated to throttle up.

The distributer is a reman. Cap, rotor, and plug wires are toyota new.

Igniter unknown.
 
Perhaps the AFM is faulty, any signs it has been taken apart?

Failing fuel pump and or clogged filter/fuel lines
 
Failing fuel pump is possible. AFM ohms out. It all points to vacuum at this point, but I cant figure out where...
 
Yeah it does make sense....how about the cross over hose from the AFM to the throttle body, if it is cracked the engine will pull in unmetered air causing a lean condition.
 
Did u check the throttle body on the efi to make sure the butterfly trap is closing enough. U could take off the big air hose from the throttle body, (I think u said it was toyota efi??), andthere will be a hole on the bottom of the throttle body, clean it off real good and put asome duct tape over the hole. Make sure its on there good enough to where it won't get sucked into the intake though! I was having issues kind of like urs, and this is what I did. I had the tps, o2 codes. Then I did this test and everything worked out.
 
yotayes88 said:
Did u check the throttle body on the efi to make sure the butterfly trap is closing enough. U could take off the big air hose from the throttle body, (I think u said it was toyota efi??), andthere will be a hole on the bottom of the throttle body, clean it off real good and put asome duct tape over the hole. Make sure its on there good enough to where it won't get sucked into the intake though! I was having issues kind of like urs, and this is what I did. I had the tps, o2 codes. Then I did this test and everything worked out.
Click to expand...

By the above suggestion that leads to the Aux air system, idle up, older 22RE engines with the throttle body bent down, have an aux air valve that was connect to the above referenced hole via a rubber hose, newer 22RE engines, straight throttle body, have an integrated idle up valve controlled by engine coolant.

Actually I just thought if something.....check the Aux Air system, the older 22REs had an aux air valve that was controlled by engine coolant and voltage, they are famous for malfunctioning. If this system is not working correctly or not hooked up correctly this could explain your issues.
 
I will check that next time I mess with it. Got fed up and started working on other parts. Made a new crossmember. Lifted the rear end. Currently waiting on parts. Lots of parts.
 
Okay... I taped the air tube. It helped noticeably. Ran it for 15 minutes and still popped codes 21/52 again. I think I need to put the o2 sensor higher up in the header or buy a heated one.
 
Okay if closing off the air bypass hole improved things tells me you have an air leak, it's either in the idle air control valve/plumbing or even perhaps the idle control adjustment screw is sucking in air. Remember air leaks have the greatest impact at lower RPM's.

What exhaust system do you have, I'm running a full header back LCE exhaust, with that system the O2 sensor is positioned back much further, I have no issues at all.
 
flash02 said:
Okay if closing off the air bypass hole improved things tells me you have an air leak, it's either in the idle air control valve/plumbing or even perhaps the idle control adjustment screw is sucking in air. Remember air leaks have the greatest impact at lower RPM's.

What exhaust system do you have, I'm running a full header back LCE exhaust, with that system the O2 sensor is positioned back much further, I have no issues at all.
Click to expand...

Full length header. O2 sensor is right under the foot of the driver. Thinking of going back to stock as I have no need for the header power or sound now. 5.29s and 34s are plenty with stock power.
 
WristPin said:
My first thought is a malfunctioning or leaking idle air control valve.
You should also jiggle the wires around see if you can locate a short.
Click to expand...

I noticed i have a very small coolant leak from tge iacv.
could one simply bypass it with a cable actuated valve? Like putting a choke on it?




flash02 said:
Still the O2 sensor at that point should have no ill effects
Click to expand...

I'm pretty sure its getting to temperature, my foot is getting warm through the firewall!


Today I idled it around and out some new carpet ib it.

uploadfromtaptalk1394422370635.jpg


uploadfromtaptalk1394422383665.jpg
 
No you can't bypass it with a cable, there are ways around it though. The later 22RE engines have a different IACV, it is completely controlled buy coolant temperature, actually it's basically a thermostat, when the engine coolant is cold air is bypassed around the throttle plate thus increasing idle RPM, as the coolant rises the amount if bypassed air is decreased until the idle is normal. A search on this forum for the later throttle bodies will give you more detail...actually I may have posted up my own conversion, not sure though.
 
Alright... today I pulled an unmolested harness from an another 86 4runner and hooked it up. Codes 21 and 52 and very, very hard starts.

So I think I have a bad knock sensor that is causing the engine to lean out which causes the o2 problem. Something else I noticed was my check connector doesn't work anymore? I can ground it at the ECU and it works no problem.
 
Okay... messed around some today.

Its done a complete 180*. Very, very hard start regardless of warm or cold. Runs 500x better though once it starts to run.
 
liljlandon said:
Okay... messed around some today. Its done a complete 180*. Very, very hard start regardless of warm or cold. Runs 500x better though once it starts to run.
Click to expand...
Your hard start can be caused by one of two or both Fuel pressure drawing off of fuel rail, most likely due to worn check valve in fuel pump The Aux Air Valve is inop, oh and what did you do to get the engine running better?

Glade things have gotten better, I'm on my second harness on my 86' Runner. Sadly a 30 + old EFI truck suffers way worse in the electrical area than a carbureted vehicle twice that age.
 
flash02 said:
Your hard start can be caused by one of two or both Fuel pressure drawing off of fuel rail, most likely due to worn check valve in fuel pump The Aux Air Valve is inop, oh and what did you do to get the engine running better?

Glade things have gotten better, I'm on my second harness on my 86' Runner. Sadly a 30 + old EFI truck suffers way worse in the electrical area than a carbureted vehicle twice that age.
Click to expand...

Relocation of knock sensor. Still have code 21. My sensor puts out 12v regardless of warm or. Isn't it supposed to be around 5v?
 
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