1992 1uz missing issues

[jonossiksilvia]

so my 1uz has some issues with missing on light load and harder
idle seems fine. gets worse once engine up to temperture

coils are:

r coil (top) is measuring 0.07 and 12.26k on output
l coil is 0.06 and 12.06k

leads are:

right coil 3.73k
left coil 4.93k
1) 4.86k
2) 5.03k
3) 14.53k
4) 15.11k
5) 16.10k
6) 16.63k
7) 10.49k
8.) 10.36k

these seem to be in spec

where else should i look?

cheers

[Pedro]

so my 1uz has some issues with missing on light load and harder
idle seems fine. gets worse once engine up to temperture

coils are:

r coil (top) is measuring 0.07 and 12.26k on output
l coil is 0.06 and 12.06k

leads are:

right coil 3.73k
left coil 4.93k
1) 4.86k
2) 5.03k
3) 14.53k
4) 15.11k
5) 16.10k
6) 16.63k
7) 10.49k
8.) 10.36k

these seem to be in spec

where else should i look?

cheers

rotors and dizzy caps

Pedro

[jonossiksilvia]

has new rotors (few months old) caps looked good so didnt replace

[kbushnz]

Isn't there a crank angle sensor up front where the cam belts run? Down low....
I hear they can get crap or water in them and give false readings to the ECU....

[jonossiksilvia]

worth a look thing is this truck hasnt even seen a rainy day yet, let alone any offroading

[Crash bandicoot]

dry huh....

corrosion on the CAS plug, is my first guess

dirt/dust on the MAF.

pull all sensor plugs and spray with wd40 give them a rub/scratch with a screw driver/ wet n dry sand paper.

take the covers off the coils and started it up one night when its dark. look for any arcing onto the any surrounding metals.

not used much? cracked split vaccum line.

start it up and spray around the exterior of the intake and manifold with crc see if the RPM's pick up slightly.

remove and clean the ICV or idle control valve, if its a jap, its had an EGR system at some stage and its probably full of gunk.

bare with me here.

The serious codes.
1 Normal Condition
(this single blink, which is not something you would normally see on a converted engine)
2 Air Flow Meter signal. (will not stop it running, ECU will default to base map)
3 Ignition signal.
4 Engine Coolant Temperature Sensor signal. (may rob power as engine will use base map)
5 Oxygen Sensor. (may rob power as engine will use base map)
6 RPM signal (Crank Angle Pulse). (critical: engine should not run)
7 Throttle Position Sensor signal. (critical: engine should not run)
8 Intake Air Temperature Sensor signal. (will not stop it running, may rob power as engine will use base map)
9 Vehicle Speed Sensor signal.
10 Starter signal.
11 Switch signal.
11 ECU/ECM.
12 Knock Control Sensor signal. (no effect to running, good to resolve)
12 RPM signal. (critical: engine should not run)
13 Knock Control CPU (ECM). (no effect to running, good to resolve)
13 RPM signal. (critical: engine should not run: 1uz-fe uses this signal to apply ignition and fuel tables, without it, the ecu has no idea where to begin.)
14 Turbocharger Pressure. (ignore for 1uz-fe)
14 Ignition signal.


The not so serious codes
21 Left Oxygen Sensor. (resolve it, but it will run without it in base map.)
22 Engine Coolant Temperature Sensor signal. (will not stop it running, will rob power, note: this is ECU temp sensor, not the dash one, there are two, this is the two wire one more central at the front. )
23 Intake Air Temperature Sensor signal. (will not stop it running, may rob power as engine will use base map)
24 Intake Air Temperature Sensor signal. (will not stop it running, may rob power as engine will use base map)
25 Air-Fuel Ratio Lean. (resolve this)
26 Air-Fuel Ratio Rich. (resolve this)
27 Right Oxygen Sensor signal.
28 Left Secondary (Sub) Oxygen Sensor signal.
(good to resolve: it's thought this might engage base map, see four o2 section for how to trick the ecu into thinking it has four when it only has two, and thus clearing this code.)
29 Right Secondary (Sub) Oxygen Sensor signal.
(good to resolve: it's thought this might engage base map, see four o2 section for how to trick the ecu into thinking it has four when it only has two, and thus clearing this code.)
31 Air Flow Meter signal (Vacuum Sensor signal). (will not stop it running, may rob power as engine will use base map)
32 Air Flow Meter signal. (will not stop it running, may rob power as engine will use base map)
34 Turbocharger Pressure signal. (ignore for 1uz-fe)
35 Turbocharger Pressure Sensor signal. (ignore for 1uz-fe)
35 HAC Sensor signal.
41 Throttle Position Sensor signal. (critical: resolve)
42 Vehicle Speed Sensor signal. (no effect to running)
43 Starter signal.
51 Switch signal.
52 Knock Sensor signal.
53 Knock Sensor signal.
54 Inter-cooler ECM signal.
56 Hydrostatic Fan not connected.
59 Automatic Transmission Temp voltage (high out or of range) ?
71 EGR System.
72 Fuel Cut Solenoid signal.
78 Fuel Pump Control signal.
81 TCM Communication. (will show up when no automatic trans is in place on crown majesta stand alone and other pre 95' ecus)
83 TCM Communication. (will show up when no automatic trans is in place on crown majesta stand alone and other pre 95' ecus)
84 TCM Communication. (will show up when no automatic trans is in place on crown majesta stand alone and other pre 95' ecus)
85 TCM Communication. (will show up when no automatic trans is in place on crown majesta stand alone and other pre 95' ecus)

[Jerry]

Check/clean air flow meter check also one of your leads isnt sparking/damaged

[jeremy]

The coils can still be way down on output, even though the resistances are still in spec. Try pick-a-part for a cheap coil to test with - some 4 cylinder toyota's have the same coils, and toyota previa's/lucida's had the same igniter as the model we have (different 1uzs have different igniters). You can get a list of models with the same bits from toyodiy.com

Are all the fuel injectors clicking?

The 1uz only needs the crank angle, 1 cam sensor and the coils/igniters to run (...I think that's all?), so you might get some clues from unplugging things and seeing what happens ...but if you're not getting any diag codes and if unplugging the air-flow meter makes things worse, not better, my (very uneducated) guess would be that its not a sensor problem.

[jonossiksilvia]

cheers guys

brings up no codes at all except normal condition.
unpluging afm makes engine worse.
icv working perfect as thought it was causing an idle issue when first started so thats been well looked at.
is getting rpm signal as tacho working on output of ecu.
leads not broken and are within specs but will try once dark to see if leaking.
cant find anywhere on how to test the ignitors (if possible)

managed to find some coils from a mate of a mate of a mate lol so will try these first. then will try spark plugs incase they have had it. (they are correct colour at moment and no signs of leaking.

it is a very similar issue to my turbo s14 when coming up to full boost (18psi) done similar issue. 1 of the 4 coils was stuffed

[Jerry]

i've got a couple of spare used coilpacks if you need them

[jonossiksilvia]

i've got a couple of spare used coilpacks if you need them

will keep in mind. am borrowing 2 coils off of a mate but wont have till the weekend

[Crash bandicoot]

Sr18's 20's Rb20,25,26's missfire if there is low fuel pressure too, may pay to shove some injector cleaner through it.

[jonossiksilvia]

Sr18's 20's Rb20,25,26's missfire if there is low fuel pressure too, may pay to shove some injector cleaner through it.

this is new to me - every nissan ive known thats had a misfire has been coils or sparkplugs.

cheers will try some cleaner and change the fuel filter too

[jonossiksilvia]

Well update dont know weather its good cos the list got shorter or bad cos the hunt still is on. Tried mates coilpacks and it still has miss fire that is the exactly the same.

[Crash bandicoot]

I dont have heaps of experience with the toyota 1uz but there are a few things that all jap efi motors have in common. this is one of them. and suffer the same issues.

the next major that will cause miss fire is the ignitior pack that sits between the engine management computer and the coils.

depends on the year of course.

for example the nissan skyline used an external ignitor pack up until 1994 which sat atop the engine on the coil cover which had 6 wires in from the ecu and 7 wires out ....after 94 it the ecu was redesigned to incorporate it.

the 1uz pack will look some thing like this

(once again depends on the year of your engine)

http://lh3.google.com/1uzsupra/R4RvvQG1 ... niters.jpg

If all is factory the ECU sends a negative low voltage/ low amp pulse to the ignitor pack and then the ignitor pack triggers the respective coil.. this is there to protect the ecu from feed back from the coils.
these can break down with age and the components inside "leaking"(for lack of a better term) signal as well

[jonossiksilvia]

cheers crash. yeah the ignitors are next on the list. there is 2 of them. least they not on the plug cover like skylines

[LOLYF]

the ignitors are common to other similar age toyotas, anything with 201 or 123 on it will work. I've picked up a couple of spares from pick-a-part pretty cheap.

Don't let anyone charge you a fortune just because it is a "Lexus" part.

[jonossiksilvia]

cheers lolyf. might have to head to pick a part. we've just had on open up in chch. wonder if they have a lot of stock yet

[jonossiksilvia]

well got it sorted and confirmed with a nice easy drive at the river.

turns out that the spark plugs that looked good colour wise and condition wise had given up so a fresh set to spark plugs and it is fixed. also wired up the power button to the ecu for the trans and it makes the auto a lot nicer - it doesnt have a mind of it own now, so to speak