brokeneck613

Hello All,

Been living on this forum for the past 2 weeks since purchasing my 1989 4runner w/3.0. I dove in to it expecting some issues since I picked this baby up for $1400.

List of things completed that haven't led to more fixes...... Yet :
Idler arm replaced, pitman arm and tie rod ends will be done as soon as puller available at Advance.
Shocks all the way around
Tore apart door switches and console switches to clean so they function again

We had a high idle of 2100 rpm when I got it and thought it may be an adjustment, that's what brought me here. Found the coolant line through the TB plugged as well as the entire heating system. The truck has new WP, Timing Belt, and radiator but they never looked at the heating side. Was able to clean out everything except the heater core so I bypassed it for now as we don't need heat much here in FL. Put it back together and idle is 850-1000.

Take it for drive and engine surges bad under hard acceleration. Found heater hose and paper towel clamped to PCV valve since previous owner/s didn't want to go through the problem of actually changing it. Read the awesome threads on how to change it, it was an amazing 4 hour job that included a dremel and a shop vac. Runs much better but has a slight skip after warming up.

Replace fuel filter - this was a chore...... Lol. 25 year old fuel fittings don't like me..

Replace all vac lines, plugs (NGK), 5 of 6 wires (Bosch), cap, and rotor. Waiting for 6th wire to arrive, the set was one short so Rock Auto sent another complete set with no hassle, I highly recommend them. Decide to go for a drive and still the small misfire, first twenty minutes was ok. Stopped and motor cooled, other wires had shown up so I put on the last new wire. Started heading home and truck ran as it did before for 5 minutes and then started running rough, no longer a small misfire.

This brings me to this thread. Truck is running like a cylinder is not firing so I pull each plug wire from the distributor one by one and find cylinder #5 makes no difference if it is plugged in or not. Remove plug wire from plug side and we have great spark. Remove new plug, install old plug so I can check new plug and we have excellent fire. Removing plug immediately after shutting engine off and there is no fuel residue on plug. I search here and other forums and it leads me to the injector.

I pull the plenum and test the injectors and all have relatively the same resistance. Find o-rings in bad shape so am now waiting on them to reinstall.

So here are my questions, hopefully I have given enough details of the journey so far.
Is it possible the injector is electronically bad even though it has the same resistance? I have a new injector on order but don't want to install it if its not necessary.
If the resistance tests the same, does this mean the injector is only clogged? Planning to send all of them off for cleaning.
Am I going in the right direction? What are the other possibilities for cylinder #5 not firing?

Thanks in advance for your help!!!

Greg

rbuchmann

Just a thought on debugging the injector issue, just from a trouble shooting standpoint, swap the number 5 with the number three injector and see if the problem moves. That would certainly tell you its the injector.

brokeneck613

That's a good idea. I have to wait on orings to arrive mid week. I may just send them off for a cleaning while I wait. Would like to be certain on the injectors when putting it back together because the plenum install/removal process necessary to "try" something out is for the birds. Lol

rbuchmann

Yea, I'm not looking forward to this process either. LOL I know it's coming though

vital22re

iTrader: (2)

Send them off for cleaning, Most shops supply all new rings on them. They can tell you right away if its bad or not. That way you'll know if all are good then you can move on to check other things. Make sure you compression check it.

brokeneck613

Sending all of the injectors to be cleaned. Should be back mid week so I can move forward. Now off to put new seals and o-rings in the p/s pump.

brokeneck613

Here's the comp test #'s:
2 = 175
4 = 160
6 = 165
1 = 190
3 = 200
5 = 175

#5 was the one not combusting and the compression seems to be good.

I decided to get re-man injectors and do all 6. The plastic plugs on the old ones are brittle and the cost is about the same.

Any other suggestions for me while I have it apart? Hoping to not have to dig deeper in to it as I need my truck. At the same time I don't want to neglect something and have to tear it apart again. Lol

oldblue

a cylinder leak down wouldn't be a bad idea, there's a 40psi difference there. Might want to see if some of the valves arent sealing good. as for injectors, i use a stethescope and listen to each one, its obvious when you have a dead one, but if an injector has an issue a lot of times you can compare the sound from a known good cylinder and tell a difference. replaced a camry injector this week for the same reason.

Foxx249

I just had the same problem...except on 3 of my cylinders (truck sat for 7 years).

Pulled the plenum and the rails, only to find i had 3 injectors clogged completely. I would get some injector/throttle body cleaner, set your injectors in a vice and just spray the crap out of them. Let them soak until the fluid goes through all the way through the injector, and repeat. My injectors are cleaned now, and I have no misfire

brokeneck613

Foxx- How'd you figure out you had plugged injectors?

I have 6 reman injectors coming in today. I'm also putting on new injector plugs as some of the wire has cracked. Hopefully by this weekend ill have it buttoned back up and running. We shall see. ��

BK2TFUTURE

How's the wires?

I had the exact same problem when I pulled my #4.

Here is my thread

#138
https://www.yotatech.com/forums/f116...30/index6.html

brokeneck613

Those wires do not look happy. Lol. I've started to tear into the harness and other than hard wire insulation that cracks when you touch it the wires seem to be ok. Replacing the connectors and any other wires that are falling apart.

Do you have and tips or recommendations on repairing the wiring harness??

BK2TFUTURE

My buddy who is a tech brought this soldering iron, extra wires and shrink wrap to repair the faulty wires.

As for putting it back, he used electrical tape (3m super 88) and wrapped it tight.

Once everything was wrapped up, we used the Ohm Meter again and had resistance!

Gamefreakgc

They should tell you if your injectors are still good. Considering they haven't contacted you, they probably are just fine.

The difference in compression is probably due to the valves. An adjustment is recommended every ~90k miles. If you have a couple of days to work on your truck (and a dealer nearby) you can get it done, just take your time and follow the FSM to a t. Better to fix it now then let it get worse and burn out your valves.

A leak down test will confirm which valves are leaking, if it's major. But taking off the valve covers and measuring the gaps will tell you more precisely.

BK2TFUTURE

Cleaning will help eliminate the possibility of a clogged injector. I thought mine was clogged too. But that was not the case.

brokeneck613

A lot has happened to the truck in the last couple of weeks. A lot of waiting in parts as well. Lol.

While I was waiting on injectors and new injector plug pigtails to show up I decided to remove the intake...... That was a process:
https://www.yotatech.com/forums/f116...e-3vze-267517/

The intake gasket was in desperate need of replacing so I'm glad I decided to tear in to it. Knock sensor wire was shot.

So here's what has been taken care of:
New valve cover gaskets
Knock sensor
Knock sensor wire, I was in there so I did both
Intake manifold gasket
Cleaned carbon out of intake and plenum (blowtorch to get it runny, brake parts cleaner, rag, copper brush, about 1 sold hour)
Cleaned carbon off egr sensor
Clean injector bases install new orings
Reman injectors: https://www.yotatech.com/forums/f116...s-3vze-267470/
Replace factory injector plugs
New idler pulley/tensioner - more on this in a minute
New plenum gasket
New TB gasket
Cleaned all bolts, plugs, misc stuff
Everything torqued to FSM

Some things I learned/used along the way:
-This site is awesome!
-A dipstick tube oil sucker, used for changing oil on inboard boats, is a great tool to help with cleaning. I degreased the block and sucked all the crap out with it. Saved a bunch of towels and mess. I used it to suck the oil out of the pockets by the valves as well when changing the VC gaskets to ensure a oil free mating surface for the new gasket
-Before removing water outlet idler gear, turn motor over to zero degrees and then zip tie timing belt tight under both cam pulleys. This will keep it from popping loose allowing the cam pulleys the skip teeth. When you turn to zero degrees to start with, if the cams do turn you know exactly where to put them back to.
-Put as many bolts/nuts in their spot as soon as parts are removed to help remember where stuff goes upon assembly, use zip lock bags or containers and label everything.
-This was a three week project, mostly waiting on parts as I kept deciding to do more the deeper I got in the motor,lol, so one thing I wish I did was take notes each day on what I did or things that happened. Would have been nice to review yesterday before the assembly process as a refresher.
-Take tons of pictures. I took a few and thought, it's no big deal, but I wish I had taken more. Not just to share, but for future reference as I know at some point ill be back in this thing.

So the outcome of all this is a very smooth running motor. I haven't driven it that much yet but the initial tests show that something in the long list of things has fixed my rough idle and #5 cylinder combustion problem. I believe it was a clogged injector, but since I have not sent the old ones off yet, I can't be 100% certain. If not the injector I would go with injector wire or plug. The only problem with doing so much at once is it makes it impossible to know the exact culprit. Shoot, it could have been the intake gasket as well.