Assorted Engine Troubles: A Thesis and a Cry for Help (1 Viewer)

[Aloha80]

My truck was having some of the same issues that yours is experiencing. It was the VAF.

Thanks man. I’ll be poking around with my multimeter tomorrow and VAF is on my list.

Side note, my Monster 796 is stuck in third after I replaced an exploded shift spring, but that’s an issue for another day and another forum

 

[DrDuc]

Thanks man. I’ll be poking around with my multimeter tomorrow and VAF is on my list.

Side note, my Monster 796 is stuck in third after I replaced an exploded shift spring, but that’s an issue for another day and another forum

Aren’t quirky vehicles fun.

 

[Aloha80]

I’m hoping that the lack of signal from G2 on the distributor doesn’t require a full replacement of the distributor assembly. That’s currently a $635 fix

1993-1997 Toyota Land Cruiser Distributor Assembly 19100-66020 | Toyota Parts

Genuine Factory 1993-1997 Toyota Land Cruiser part # 19100-66020 - Distributor Assembly. McGeorge Toyota Parts is your choice for Toyota Parts and Toyota accessories. We are a factory authorized Toyota Dealer with Toyota parts and Toyota accessories all at wholesale prices for your Tundra...

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[South Texas 97]

I have a brand new in the box distributor available for a very reasonable price in the classifieds.

 

[Aloha80]

Further multimeter test results:

VAF:
-VS-E2: 264.2 ohms
-VC-E2: 282 ohms
-THA-E2: 2.197 k ohms at 21° C

IAC (just at pins, still intend to remove and clean):
-B1-S1/S3: 21.1 ohms
-B2-S2/S4: 21.1 ohms

Quintuple checked G2 resistance on distributor, still nothing.

VAF connector is possibly missing a female connection, unless this is normal (pictured). Can’t figure out what the corresponding male pin does as it’s not listed in FSM for VAF testing. Also, that gasket on the air box side looks like it’s seen better days.

 

[Aloha80]

Opened up the distributor to measure the air gap between the signal rotor and pickups. Then realized I’d have to turn the engine to turn the distributor, and I don’t have a shallow enough 30mm to turn the crankshaft bolt. Not sure it even really matters if I have no resistance from the G2 pickup anyways—just thought I’d be thorough before committing to a new distributor.

Cap internals look clean, minor corrosion on rotary assembly, minor oil leak, other than that everything visually looks okay to me.

EDIT:
Got the distributor to spin by chirping the engine. Gaps:
NE: ~0.279mm
G1: ~0.432mm
G2: ~0.279mm

 

[Aloha80]

Okay, finally had time to put in a new distributor (thank you @South Texas 97). It went about as smooth as one can ask for!

I chose not to remove the valve cover, mostly just to save time and to see if I could get everything in spec without doing so. I think I got it right.

Followed the FSM to set the timing at 3° BTDC at idle with A/C off, transmission in N, and engine in diagnostic mode at normal operating temp.

Once out of diagnostic mode, idle hovered between 3° and 10°, within FSM spec. Engine idled at between 650 and 670 RPM, averaging 660 RPM.

Just to be extra ridiculously meticulous, I tested the resistances of the new distributor pickup coils. At 36° C, the coils were all in spec and registered:
-G1/G: 257
-G2/G: 261
-NE/G: 262

My bet is that the EGR code will return, but for now, hopefully the RPM signal code is solved.

 

[Timpanogos Slim]

Well boys, found my newfound idle issue and certified myself as a complete idiot.

Was going about inspecting the throttle body and look what I found:

Back when EMSPowered still existed, they sold a simple mandrel-bent stainless pipe with some silicone couplers to replace these. At least for 95-97 trucks. Would be great if someone else started selling a similar product.

It may be possible to glue your original one back together with a good urethane adhesive after degreasing - I've done a couple similar ducts (different vehicles though) with this product:

Amazon product ASIN B001XUMBIA
The best idea i ever had for repairing these was large diameter adhesive lined heatshrink, which absolutely does exist in sizes big enough, but when i looked into it 10 years ago it would cost something like $600 to buy a lengh of the stuff that you could cut down to wrap maybe 3 ducts which seemed like too much.

Edit: Hundred bucks for a 4-foot length of 7.1" diameter 3:1. Maybe someone should test this theory. 3:1 Heavy Wall Adhesive Lined Heat Shrink Tubing | 4 Ft Length - https://buyheatshrink.com/heavy-wall-adhesive-lined-heat-shrink-tubing

 

[Aloha80]

Back when EMSPowered still existed, they sold a simple mandrel-bent stainless pipe with some silicone couplers to replace these. At least for 95-97 trucks. Would be great if someone else started selling a similar product.

It may be possible to glue your original one back together with a good urethane adhesive after degreasing - I've done a couple similar ducts (different vehicles though) with this product:

Amazon product ASIN B001XUMBIA
The best idea i ever had for repairing these was large diameter adhesive lined heatshrink, which absolutely does exist in sizes big enough, but when i looked into it 10 years ago it would cost something like $600 to buy a lengh of the stuff that you could cut down to wrap maybe 3 ducts which seemed like too much.

Edit: Hundred bucks for a 4-foot length of 7.1" diameter 3:1. Maybe someone should test this theory. 3:1 Heavy Wall Adhesive Lined Heat Shrink Tubing | 4 Ft Length - https://buyheatshrink.com/heavy-wall-adhesive-lined-heat-shrink-tubing

Managed to snag a new one from Toyota, but good ideas for when someone inevitably runs into the same issue!

 

[Aloha80]

Update: 5 minutes into my first test drive, MIL/CEL is back, this time with 26, running rich. Weird, but at least familiar.

Edit: turned off after some more driving. Satisfying but not diagnostically helpful

The idle is a little low when just reaching operating temp (~600RPM) but other than that, I’m not seeing the same misbehavior from the engine.

Like I said, I’m sure the EGR code will come back and I still plan on running through the various systems.

 

[toy_tek]

How does the wiring harness look where is passes the EGR pipe? If you haven't already I'd recommend opening up the loom a bit and checking for wiring damage or intermittent shorts in there. The heat from the EGR pipe causing issues with the wiring harness is a common issue (it happened to me as well and was difficult to diagnose).

That wiring harness connects to the distributor. Perhaps there's an issue with the wire to the distributor inside the harness causing CEL for code 12.

View attachment 3477756

This is where my money is.