Code 22

[Zuffen]

My engine (90-92 Soarer) it throwing up a code 22, water temp sensor.

I've checked the sensor with another and they read the same resistance so I feel I'm safe in saying it's OK.

I've checked continuity of the earth (brown wire) and THW wire (pale green) back to both earth and the correct plug ion the ECU.

All seems in order but it has a "hunting" idle and keeps throwing toe code.

Other than a poor connection between the loom plug and the ECU I can't see where the problem lies.

The ECU is a known good unit.

Any suggestions on a cure would be appreciated.

 

[gloverman]

The plug on the temp sensor is prone to corrosion or breaking. Also try tightening the connection of the terminal into the ECU.

 

[Zuffen]

Kelvin,

Thanks for the advice. As usual it was accurate.

If I'd used my brain I would simply checked for voltage on the green wire at the temp sensor!

Oh well that's what you get for working on your car straight after a 40 hour flight!

I found the plug at the ECU was the problem. I de-pinned it and substituted another wire and temporarily joined them.

Reset the computer and it now starts and doesn't throw any codes.

Only problem is I still have my high and lopping idle.

I tried closing of the fuel return line and it tried to stall, as I would expect it to.

I then closed of the ISCV line and it stumbled and tried to stall, as it should.

It will rev cleanly but does smell a little rich.

Perhaps I should take it out for a run and see what it's like after a half hour?

I haven't driven the car more than 2,000klm in the last 5 years and I just want to drive it again.

 

[gloverman]

I might have seen the poor connection at the pins a few time now.

For the idle you are right to give it a good drive. That usually sorts it out but I see a lot of steppers that get a bit sticky after sitting , even after a short time if they are a bit dirty.

 

[Zuffen]

I'll give it a run and see how it goes.

I have a spare ISCV so can always change it out if it doesn't fix it.

 

[Zuffen]

Gave the car a run and it still has the high lopping idle from 1,000 to 1,300 then it drops back to 1,000.

It sounds like a fuel cut as the engine just drops down in a fraction of a second.

When driving if I drop down to under 1,300rpm it just about throws me though the windscreen the effect is so pronounced.

At one stage I had a CEL but when I went to check it there was no codes only a constant flashing light. When I restarted it the CEL didn't light up.

Drove a few hundred metres and the CEL came on but again nothing when I checked it.

Not sure where to look from here.

I may change the ISCV tomorrow and see if it has any effect.

 

[gloverman]

Rod Can you do a bit of a test for me please.

With the key on , engine off please check the power to the IAC. Unplugging the unit is fine for this. Keep checking the power and start the engine. You may need to keep the revs up using the throttle. After the engine has run for about 20-30 seconds turn the key off and keep an eye on the power to the IAC. If it goes out straight away there is an issue.

Then repeat the test a the +B terminal of the ECU. Cheers

 

[Zuffen]

Ok did the test and found no 12volts at the ISCV.

This also meat no 12volts at the diagnostic port, but I don't use it so would never have known.

I'm currently running the fuel pump off the ignition so again hadn't noticed the lack of 12 volts.

I fed the loom 12volts via the diagnostic port as a quick and dirty way to see what happened.

As the ECU had been powered down during the checks I probably need to go for a drive and let it re-learn so the idle may yet settle.

Not sure where the power went but this is the next search. The loom had some damage when I got it so I suspect a broken wire or two.

Unplugging the ISCV and re-inserting it takes about 45 minutes as the plenum is rotated 180degrees and it's hard up against the rear wiring loom. I have to remove the plenum to get the plug on or off.

To add to the misery the bonnet opening is 1325mm off the ground and I'm all of 1650mm tall! I have to work off a milk crate or crawl on top of the engine to work back there.

Learning to not like this one little bit.

 

[gloverman]

When I back home after the weekend I will email you some helpful hints on the wiring which should help sort the idle out. Cheers

 

[Zuffen]

Sorted power to the ISCV via B1 @ B2 and the power now shuts down a few seconds after the engine stops.

I took the car for a drive and after about 10k's it started to idle very low (almost stalling) then it finally did stall.

It didn't want to re-start but I changed the plugs and it started but wouldn't rev over 1,500rpm.

Fortunately that happened in my garage.

Checked this morning and it doesn't want to fire.

One other weird thing it does is the CEL lights up whilst driving but if you try and check for a code there isn't anything there (the CEL is wired to a button under the dash). When you re-start the CEL turns off like it should but comes on again after about 200metres of driving.

It's got me bushed!

 

[George_R]

maybe you have some failure in the BATT circuit? (one that provides uninterruptable power to ECU memory). Have you tried to check for the codes while the warning light is still on?

 

[Zuffen]

G'day George,

Yes I've tried to get a code when the light is on but it won't flash.

I'd thought about adding some LEDs to tell me if I lose power output from any relay but haven't done it yet.

What I did just find was I fitted a fuel pressure gauge I had kicking around (it even had all the right fittings on it) and it tells me I'm getting about 12psi fuel pressure.

Only about 30psi too low.

I can't find an old UZ FPR but I have a Malpasi R/R FPR which I'll rig up tomorrow and see if it works.

The tank has around 15 litres of fuel in it so I know it isn't out of gas plus the fuel pump is a brand new Bosch injection pump for a Holden (we all use these in Australia) with less then 2 hours running time.

I can hear the fuel returning to the tank which also confirms it isn't out of fuel.

No idea why it would want to throw a CEL due to fuel pressure a it doesn't monitor fuel pressure but perhaps it's running so lean the timing is so far retarded it isn't happy.

I'd noticed some days it didn't want to start without cranking for a while. Could have been low fuel pressure as well.

Perhaps I'll have better news tomorrow.

 

[Zuffen]

Ok I now have fuel pressure but the car still doesn't drive as well as my first 1UZ.

It doesn't want to rev past 4,000rpm and sounds almost like the timing is retarded.

Still getting my CEL but no codes either when driving or after its turned off.

Once you re-start no CEL but after 100metres there it is.

I think there's a dodgy connection in the 40+40 plug as if you jiggle the wires it will stall.

To me the engine is losing spark as it stops abruptly and not like its running out of fuel.

I'm contemplating getting the 40+40 plug from a Soarer at the local wreckers and grafting it onto the loom.

If this fails I'll rip out the wiring and re-do it as it doesn't make sense why it runs poorly so I'm leaning toward doing something wrong when wiring it up.

 

[George_R]

Never seen the 40-40 plug closely , but I suppose it may have loose connection in the TE1 (TC) pin, so ECU does not see your request to enter diagnostic mode?

How did you get the pressure back to normal?

With the connectors I'm used to, it's quite easy to pull the pins one by one, tighten them with pliers and put them back. If that's possible, I'd start with tightening the diagnostic mode pin, then read the DTCs thus narrowing the search of other loose pins down to some 10 of them.

Another way to search for loose pins: start from jiggling most important wires one by one. Maybe do so with BATT, IGSW, +B1,+B2 ,E1. So you know the power flow into ECU is never interrupted. Then find out if there's any problem with crank sensor pins (can't recall their names). Then maybe IGT1,IGT2,IGF1,IGF2.

I was fixing a vvti 1UZ the other day, and at some moment I had to figure out what's the minimum set of sensors that would make it start and run. Turned out it's just the crank sensor alone. It even runs on 4 coils out of 8 connected. Think non-vvti 1uz is the same story, that's why I feel you should check the pins in the order given above. In particular, I feel it's more likely to be crank sensor or power input than anything ignition related. Pay maximum attention to crank sensor pins at both ECU and sensor side, also check if its shield has earth. It's common to have rough engine work and rev limit if there's some problem in the crank sensor signal.

 

[sideshow]

maybe the ecu is stuffed
I get afew customers buy 2nd hand ones and they are even worse
don't change the 40 40 plug
having 60 more solder joins is dodgey as all fk
get the plug and while engine is running pull on each wire at a time and u will find which wire is faulty
get a very tiny pick and tighten the terminal
or all terminals
then throw it out and fit a link ecu
ive got 3 x 2jz ecus all stuffed due to capacitors

 

[gloverman]

I've rebuilt the ECU Jim and test driven it on my own vehicle to ensure its good. Even put the scan tool over it before sending it back.

 

[sideshow]

Ok cool
He should at least spend couple hundred bucks on a good scanner

People who play with cars all the time should really invest in one

 

[Zuffen]

Jim,

I have a scanner but its OBDII only so I'll go buy one for the UZ.

Despite the problems I'm having fun as each time I solve a problem I learn something.

You're right about replacing the 40/40 plugs as it only introduces more potential problem.

George,

I replaced both pre-pump fuel filters after only 2,000klm they were blocked!

I'll go through the wire tug test (I did a bit of that yesterday)and see how I go.

I plan on redoing the wiring one day next week.

 

[sideshow]

send yr 1uz loom to killa customs
I heard he does good work hahahahaha
if u can get a hold of him when there is problems

 

[Zuffen]

Jim,

Excellent idea,

Then it won't run so I won't have any problems)