4Runner4

Hello. I have a 93 runner with 3VZE. 5 SPD 168K. I bought her at auction 5 years ago, as is, no test drive kinda thing. It has always been a secondary driver so I think I have put about 10K on it. Ran rough, poor mileage, Lots of vibrating under 1400rpm. What sounds like a lifter tap only goes away when accelerating in higher rpm range.
First thing I did. Oil change. Replaced plugs and wire set. BG44K. Air filter. O2 sensor. Did not help at all. Has been running the same for years. I live in Denver and have never driven it at lower alt. I have had it up to 11K feet and it seemed to run fine. I have never seen it get hot or had the check engine light come on (does not read any codes with E1 TE1 are jumped). Has never broke down on me. It is going to be my daily driver for a bit so she needs some love.
I just had Toyota do a steering rod relay recall when they told me there is also a recall for head gaskets. So I had them do both which took a few days but looks to me like they only did gaskets on the valve covers. Did I get shorted on my recall? Service Paperwork said 3 cylinders misfire and water pump leaks. Did not tell me which cylinders or give me any info about the lifter/heads which do make some noise as stated above. Seems like the service guy who helped me (don't think he was a trained tech. paperwork guy) played dumb and just wanted me to be on my way after I politely asked some questions about the trucks condition.
Yesterday I pulled the plug wires one at a time off the distributor and cylinders 1,2,3 did not change the idle when disconnected. 4,5,6 clearly dropped idle when pulled. This morning before driving I pulled spark plug 1 and 3. both looked good and where gaped correctly. Can I test injectors with intake manifold on? If anyone has some input that would be awesome. I can give more info but will start here for now. Thanks, Kyle

wrenchmonster

Don't go chasing your tail. Make sure you have a mechanically sound combustion chamber. Do a compression test on both sides, first and foremost. I hate to say it, but I've got more than 10 years at a dealership service department (not Toyota) and often a job like this recall would be given off to a lower level tech as a way for them to gain experience. If the tech botched the job and they kicked it out the door it's their responsibility to repair. If they had the heads off, they should have at the very least visually inspected and flow-checked the valves. Having the top end open is a good time for them to make money with the recall. So if you needed valve work or new cams or new timing belt components, etc. the service adviser would have called you back and tried to sell these things to you. The old "Well, it's not covered by the recall, but you wouldn't have to pay the additional labor, just the parts..." speech. This is the same reason dealerships often have the cheapest oil changes. They don't make any money off the oil change, but off the other items they find wrong while they are doing the oil change. But I digress. First things first, do a compression test. Also in the future, make sure they know you want to see your old parts when you come to pick it up.

4Runner4

Good call on the old parts. I did the compression test when I did the plugs 5 years ago. 120 range on all. I just poked around some more and did see the new silver colored gasket on the head. guess they just didn't want to tell me what was wrong with the top end. I see the harness plug on #2 is blue not gray. So someone had to work on the EFI wiring. If I grab an ECU from the junk yard does is need to be 93-95 or can I use an older one? any reason switching ECU would be a bad idea? Thanks WM. Kyle. Did not run any different after gasket recall so I think they did the work right.

wrenchmonster

Well, personally I'd still do the compression test. 120 is a bit low. At 168K you'd typically see about 150. But let's assume for now you don't have a mechanical issue. That leaves fuel and fire. Seems like you've already found a problem with the ignition system. Make sure the wires are routed correctly. Let's get a little terminology straight, just in case you don't know and for any one else who may read this later. But left and right sides of a vehicle are noted as if you were sitting in the drivers seat. So the drivers side is the left side, and the passenger side is the right side. Okay, now check your ignition wiring routing. On the left side you have the even bank. As you stand in front of the engine the cylinders are 2, 4, and 6 going back towards the firewall. Respectively on the right side is the odd bank, so you have 1, 3, and 5. Most distributor caps are labeled with the corresponding cylinder number. So make sure the spark plug wires are routed to the correct cylinders.

It's unlikely that if the ignition coil was working properly and sending spark through the distributor that you'd have lack of spark unless those particular wires you mentioned (1, 2, 3) were bad. But a way to check this (beyond a resistance check of the wires themselves) would be to simply swap the "failed" wire to a known good spot. So take #2 for instance and exchange it for #4 and see if now the misfire "follows" the wire and #4 does not drop. If that is the case, then you have a bad wire set. Seeing as you replaced the wires, again I see this as an unlikely scenario.

That would leave fuel. Remove your upper intake manifold to get to the wiring harness on the injectors. Install a noid light on the suspect injectors and see if you get a flash. A noid light is basically a L.E.D light that is made to fit the connector for the injector. If you don't have one you can buy a L.E.D and insert it in the connector, just be VERY careful not to damage or bug out the pin in the connector. Anyway, the light should flash as you crank the engine over and it tries to start. If you're not getting an electrical signal to one of your injectors then you have to check the wiring. If you are getting a good electrical signal to all of your injectors, then I'd suspect you have a failed injector. Now you'd have to remove the injector rail for all cylinders and see which ones weren't working, which should in theory should correspond to cylinders 1, 2, and 3 if everything else were working.

Alternatively, if you feel that compression is good (again I'd check to make sure, you just had someone do major work on your engine) and the spark plug wires were all routed correctly and firing off (in other words you've narrowed it down to an injector wiring problem or injector problem).... One thing you could do before pulling the upper intake would be to run some marvel mystery oil in your fuel to see if you have a stuck injector. You *might* get lucky and unstick it, but chances are if you've gone this long with the truck running the way it has you won't.

But all of this information I'm giving you is getting ahead of yourself... just as trying a different ECU at this stage. Do the simple things first. Check the routing of the spark plug wires. Check compression. I'd do those before anything else.

4Runner4

Right on. Yes. spark is there and wires are correct. 1,2,3 MIS. From the sound of it the lifter tap is the only mech issue.
The second comp. test and the noid light is what me and my friend where talking about doing next. Although he is a trained tech, V6 Yotas are not his thing so I wanted to see what the community thought about it.
Really appreciate you Jumping in on the post!! I think this manifold has to come off and fuel issues need corrected. The new ECU was a thought because suspected damage to EFI wiring(Blue plug on #2). I can live with a lifter tap if this thing fires right.
Let ya know where I get on it. Thanks. Cool snow dog

Gamefreakgc

120? I have 160 range on all 6 at 283k miles

Not sure what to tell you if all cylinders are at 120...

RSR

Were it me I'd take it back to the dealership and get a service manager involved...

That they marked problems and never gave you the opportunity to repair while torn apart for recall items is nuts.

wrenchmonster

You bet, glad I can help. Post back with your results when you and your friend get it figured out.

The dog, Terra, passed away years ago unfortunately. I just can't bring myself to change the picture She was a great dog, I sure miss her. Dogs are the best.

big bear

Her's a copy and paste from one of my threads, I wasn't aware of this fact, but it makes perfect sense.

RJR
Registered User
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Join Date: Jul 2012
Location: Northern Colorado
Posts: 86


If I read your signature correctly, you're at Big Bear Lake, CA. The elevation there is over 6000 feet, so your numbers are about right. Compression numbers will drop about 3.3% per 1000 feet, so you should be down around 20% from sea level numbers. So, if 150 is normal at sea level, you should be reading around 120 psi.
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RJR (Ron)

1994 4Runner, 3.0, 5-spd, 4.56 gears, 190K miles
Front: IFS, Aussie locker, Aisin manual hubs
Rear: Detroit True-trac LSD
31x15 BF Goodrich All-Terrain A/T