Herkdriver

Ive posted my problem at length on the "other" forum, but want to pitch it to y'all to get more opinions. Quick & dirty, I removed/replaced injectors to send to Witchhunter (leaky). Replaced a lot of other stuff too (see link). Ran fine before I tore it down. Didn't check codes before hand, but now getting a code 24 when I jump the diagnostic ports. Click the link for my saga:

http://www.toyotanation.com/forum/80...ml#post4031813

I've tried almost all I can think of, other than swapping the ECU. Any tips, advice, been-there-done-that's etc. are appreciated.

MudHippy

Man you are lost. Thankfully you came to the right place...

So, with the IG SW ON and intake air temperature 20°C (68°F), the STD voltage at the THA - E2(E21) terminals should be .5 - 3.4V. Not 3 - 4V.

See pages 190 & 193 of the FSM for the voltage specs, and proper procedures to diagnose code 24.
http://personal.utulsa.edu/~nathan-b...86troubles.pdf

If the ECU is the problem, then it is. If all else checks out good, then there's nothing else to do but replace it.

Herkdriver

, you're right it's not 3-4v. But my genuine FSM states "1-3v" at 68*. And the location of the THA terminal on my '89 is different from the diagram on your link. I'll re-check the voltage today just to make sure; I'm not confident my multimeter probes were making good contact in that tight space.

Can you think of anything else I've missed? Thanks

Gamefreakgc

If you're still looking to replace the connector, it's not hard to do. Just stop by the junkyard, clip off the connector with plenty of spare wire and solder the two together. You can pickup a soldering kit from Radioshack or Fry's pretty cheap. Did it for my cold start injector switch, so those connectors can periodically go bad. However, mine was very corroded and stuck to the top half of the switch. If you can see any damaged bare wire after removing the tape I'd replace it (bare wire alone will still hold a current unless it touches other bare wires).

MudHippy

You have a genuine 89 FSM? Well why didn't you say so? You should scan the 3VZ-E section and post it up for the rest of us. I myself have only seen 2 pages of the 88 FSM V6 supplement. Stupidly enough, one of those pages does state 1-3V.


The other page shows the 88 ECU pinout.


Anything else available online is for 93+ 3VZ-Es. Which kinda sucks for those of us with some of the earlier models. Shouldn't everything be available for free on the internet? Hint, hint...

Herkdriver

Thanks guys. I'll check the cold start injector plug too. Looks like it may have been rewrapped at some point. And it takes a little cranking to start her up when cold. I chalked it up to the code 24, but its worth checking out. Still need to double check the voltage at the ECU plug. Just put my mind at ease here: will the code 24 cause her to shudder/miss below 2000 rpm?

Mud hippy, I'll post up the page from my genuine '89 FSM. Bt damn that's a lot of scanning/copying/uploading to get the whole manual on here. I don't even have time to get my truck running right.

Herkdriver

Re-attack on the voltage:

THA-E2 is 4.9 volts. Spec is 1-3 volts. Triple checked, with good connections at ECU terminals and multimeter. What does higher voltage tell me? Is that bad? Thoughts?

Chooch

I was running rough all your symptoms and it threw a code 24.

2 days later my top end was torn apart to do head gaskets...Hope you aren't as unlucky as I was.

Herkdriver

You and me both!

Anyone k ow if the IAT sensor could still be bad even w/ good voltage and resistance?

Herkdriver

This would be a very lengthy post, so I'm going to break it up into several to document what I've done, and the problems I'm still encountering.

My Code 24 turned out to be a bad IAT. Even though it ohmed out good (per the FSM) it was bad. The voltage checked at the ECU was out of spec (showed 4.95v while the FSM stated spec is 1-3v). Bought a remanufactured "Cardone" AFM, plugged it in, and the code 24 went away! Awesome, except the truck still ran like crap. I guess it was a little better, but I was still having the misfire and hesitation, almost like a sputter. Below 2000 rpm.

Back to square one. Checked the TPS (thanks 4crawler...http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml), and found it within FSM tolerances. By the way this is very difficult to do w/the throttle body installed. I removed mine and tested it on the bench:

VTA-E2, zero gap: .58k ohms
IDL-E2, .5mm gap: 220 ohms (seemed very low, but FSM says <2.3k is good)
IDL-E2, .77mm: infinite ohms
VTA-E2, throttle full open: 3.95k ohms
VCC-E2: 5.5k ohms

Checked TPS voltage at the ECU, all w/in FSM spec:

IDL-E2, throttle valve open: 10.8v
Vc-E2: 4.9v
VTA-E2: 0.42v (throttle fully closed)
VTA-E2: 3.7v (throttle fully open)

TPS is ruled out. More to follow...

Herkdriver

Replace the spark plug wires w/7mm Denso units. Resistance of the existing wires was w/in FSM spec, but quite a bit higher than the new ones.

Fixed two factory wire splices that the PO had wrapped with crappy electrical tape. They were the E2 wire from the AFM, which splices with the TPS, coolant temp sensor, #6 injector, and ECU E2 wires (brown/black stripe). And also a green/black wire from the AFM that joined two other green/black wires.

Herkdriver

That splice/elec tape job is right below the heater hose, which had been leaking very slightly at the t-fitting the PO had installed to flush the cooling system. I used solder-filled butt connectors, shrink wrap, and conduit to clean it up and protect from future problems. I did this before I replaced the AFM, and I was still getting a code 24. So my last resort was to replace the AFM, which I talked about in my last post. Onward!

Replaced all vacuum hoses and checked (again) that they're routed correctly (very helpful link here…https://www.yotatech.com/forums/f116...572/…and also here…https://www.yotatech.com/forums/f116...925/…and a no-brainer here…https://www.yotatech.com/forums/f116...e-help-209069/)

Checked the distributor per the FSM:

Airgap: .305mm and .25mm
Pickup coil:
G1-G: 179
G2-G: 178
Ne-G: 178

New cap and rotor (non-OEM, but my Toy dealer never has anything in stock and I wanted it “now”).

New Denso OEM spark plugs, gapped per the FSM (.030).

That .25mm air gap is just barely above the FSM minimum (.20mm). But it is w/in spec, and it seemed fine before my recent problems, so I'm going to say the distributor is not the source of the problem. However, when I checked timing, it was hard to read, bouncing around between 10 and 12 (hard to see).

EDIT: I jumped TE1 and T1 while checking the timing. The timing mark was hard to see, but from what I could tell it was bouncing between about 10 and 12.

Herkdriver

Dash pot checked…it DOES NOT check out per the FSM, but it wouldn’t cause the misfire/rough running, would it? It’s on my list to replace.

Cleaned throttle body and IACV with throttle body cleaner. The IACV was a bit gummed up when I inspected it. Sprayed throttle body cleaner through the hole in the throttle body, and also removed the cover (the one held on by 4 screws) and sprayed inside there. I was able to rotate that shaft fairly easily.

Herkdriver

More to follow, including a pic of the IACV.

Herkdriver

Burped the cooling system after I put it all back together. There was a lot of air in there, and I’m not sure I got it all out. That’s also on my “to do” list to finish up.

After all that, I put it back together and started it up. Hard to start, then sputtered to a start on the 3rd or 4th try. Initially idled up to about 1500 rpm, which tells me the IACV is doing it’s job, right? Then idled dropped to about 900 once warmed up. Another indication the IACV is working properly. But still a misfire and hesitation below ~2000 rpm.

Herkdriver

Almost forgot to mention: The AS valve (Air Suction—newer models called it the PAIR) is bad. The reed valves are letting exhaust gas blow back into the intake. So I disconnected the vacuum hose for the AS diaphragm and plugged it at the upper air intake. Runs much better now, but not right, still

So then I started thinking cold start injector problems. The cold start injector was previously sent off to Witchhunter, good flow, no problems. And I used a new CSI gasket at the upper intake. By the way, did I mention all copper crush washers/gaskets were replaced?

Well now, after about 50 miles of driving since the injectors were-reinstalled (w/all new orings and such), the #1 and #6 injectors are leaking.

I was very careful to reinstall everything per the FSM. Especially cautious of pinching orings or seating them at an angle. So it’s back full circle to where I started. Apparently I made a mistake on the injector reinstall. Any suggestions on doing it right? Anyone have them leak even after new orings?

EDIT: forgot to mention that I pressurized the fuel system using the FSM instruction, jumping B+ and Fp. I don't have a fuel pressure gauge, but I heard the pump operating and there were no leaks anywhere at the injectors, fuel pipes, fuel rails, FPR, or FPD. Again, I drove it about 50 miles after the re-installation of the refurb'ed injectors with no fuel smell nor leaks.

TNRabbit

I've had my top end off 3 times & never had an issue with injectors leaking. Not sure what to tell you.

Herkdriver

Not sure what the deal is either. I'm bringing it to my indy mechanic to let him have a look. I'll post up my findings. Thanks.

Gamefreakgc

I just installed injectors in my truck recently as well, did you use a torque wrench? Not enough torque won't "crush" the washers and too much might damage the fuel bolts. The injectors should rotate right and left even after installing the fuel rails, if they didn't then something isn't right. Fuel rails could be on too tight. Also, you need to lubricate the o-rings with fuel (the injector guy said to use grease) before inserting them into the intake manifold and fuel rail. I found that using a cotton swab and lubricating both surfaces worked better since mine were a bit snug. Also, I found that for the thicker o-rings on the pindle cap, it was easier to insert them into the intake manifold first, then place the injector inside of it. I almost ruined one trying to do it the other way around.

About the Dashpot: It's not that vital. It's for reducing emissions so if your's isn't to spec (like everyone else who has a 3VZ-E) don't sweat it. Mine had always been broken and I just took it off, ran fine except for a little bit of a "jerk" when you let off the accelator. With my "new" one on it's smoother. Yours is busted, you're missing the air filter and cap. Try and take one off at a junkyard (Camry and Corollas use the same kind) if you can. If the spring mechanism doesn't work at all, don't get it. If it does, you can adjust the screw on the throttle body to increase/decrease the gap. This is low-priority though.

About Cold Start Injector: Unless you live where it snows or reaches sub-freezing temps regularly, this would not be your issue. I asked the guy who did my injectors about the CSI and he said not to bother and just clean in gasoline to remove the buildup if I wanted (I did). It only runs for 15-30 seconds on cold mornings where I am at (lowest temp I remember was 28 degrees). So if witchhunter says there's no leaks through your injector, it's not your issue. Once again though, be sure the fuel line and nuts to the air chamber are tightened to spec.

Removing the EFI fuse would make it run better temporarily because code 24 and code 25 (rich/lean error codes) are on a 2-fault system. The first time it happens it records it in the ECU and the second time throws the CEL. It will never go away, trust me on that one. Just fixed a code 25 after 4 months of resetting the EFI fuse several times a week since I was sick of looking at it.

Herkdriver

Gamefreak,
Yes, torque wrench used and I [I]thought[I] I installed them correctly using FSM guidance. Also saw the thread here showing what crushed spacers look like. I'm hoping the orings were somehow damaged and just need replacing, instead of a damaged injector. My indy mechanic is looking at it now.

Thanks for the info on the dashpot. I'll search the junkyard and replace if I find a good one.

AFter I replaced the AFM, the code 24 was gone and I had no other codes. I'll update when I have more to say, hopefully good news. thanks!