Cylinders 2, 4, 6 misfiring

Hey guys, new here! Just picked up 92 4Runner with the 3vz-e auto for cheap(PO couldn’t figure out misfire). Had an engine replacement with an engine from yotashop.com in 2020 at 215k, is now at 230k. When I picked it up, starts but idled like dog like BAD, had to keep throttle on to keep it alive and barely was able to get it on a trailer, kep bogging wanting to die and wouldn’t go above like 2-2.5k. No CEL displayed at any point. I personally Replaced plugs(checked gap), cap, rotor, fuel filter, and verified fuel pump in working order. No change. Changed the fuel pressure regulator, vehicle starts, idled nearly identical but stays idling without throttle, if I give it throttle it will now rev past that 2-2.5k, it sounds like it’s starving for fuel but I’m also smelling fuel, no drips. Changed fan pulley since it was so bad was worried about fan self destructing. Verified timing while I was in there. Started, still runs like ass. White smoke out tail pipe til warmed up then smoke clears up. once warmed up vehicle is idling better but still missing. Sprayed maf cleaner everywhere to check for vac leaks and nothing. Still no codes, just consistent CEL flashing when pins are jumped. However, the whole driver bank is missing, 2, 4, 6. Verified distributor is firing by pulling plug wires one at a time verifying spark for those cylinders. Thinking head gasket or injectors clogged(I’ll ˟˟˟˟˟ a brick if it’s all 3 injectors on the same rail)but waiting for a comp tester to check compression.
Yes, I’ve used the search bar here aswell as other pages/forums.

 

First thing is to do a compression test. There is a reason that the problem is all on one bank of cylinders.

 

That’s what I had figured. Getting tester in the next few days will report back with compression. Gonna check for spark at the actual plug also, since I only checked at the distributor having it spark to the plug wire from a 1/2inch away.

 

What do your plugs look like? What did the old ones look like? They tell the tale...

https://www.championautoparts.com/P...-and-maintenance/how-to-read-spark-plugs.html

 

Old ones were absolute trash. Replaced with what new plugs came with it, champions, gapped to .032. Honestly I wouldn’t be surprised if they used the plugs from the previous engine. Seems just about everything else around was reused(nothing against, I’m a cheap bastard myself). 15k and blacker than hell all around.

 

Just can’t see a HG goin in 15k miles. Not that I’d be surprised(crossover issue with 3.0, exhaust is heat wrapped near cyl 6)

 

Did just look around, my intake ground to body and driver side block to frame are both in meh condition. Gonna start wiggling some wires while running to see if there’s a short. Not sure the driver injs are even firing. Would mismatch inj’s cause this? I did notice it has what appears to be yellow high flow inj’s(FOTE-D5A) on the drivers side. However the pass side one that I can see has a different part no.

 

I would def do a coolant test for exhaust gases. That white smoke doesn't sound good.

You may be chasing a few issues. Black plugs usually mean a rich condition.

 

no smoke or burbling in radiator. Pressure builds fine also.

 

If it were me. I'd then do a compression check. A coolant check and if it's good. Then just tear apart the top of the engine and redo it all. Sounds like it's a mess. But I'm also a stupid glutton for punishment.

 

Going to do the comp test and check a few other things this weekend. Between working FT & having a 6mo old it’s hard to get out there haha.

 

Possible dumb question but are you positive about the plug wire connections? And the quality/condition of the wires themselves?

 

no question is a dumb question! Haha.
That’s what I’m thinking honestly. Did notice today the insulation around the ground wires(top of intake to body and next to distributor to the body) is cracking and the grounds themselves don’t look the best. The one next to the distributor is also coated in oil. (Believe the seal between the dist and block is bad, will get to that later)

 

Wouldn't be a first time some yahoo swapped his plugs or wires to fix a misfire and screwed up his firing order and wound up junking his car.

 

Oh sorry I thought you meant inj wires. I think there’s something up with the inj wiring. Plug wires are correct. I know the firing order 1,3,5 pass side front to back, 2,4,6 front to back driver side.

 

...or that. I am very curious what you find. Is this an OBD1 setup? Can OBD1 detect a misfire?

 

OBD1 and no codes. That’s what’s leading me to think something wiring/ground related. No miss is detected
Edit- drove it down the road after letting it warming up the other day to see if maybe it was gunked, tried to bomb it, BARELY got to 35 and took legit 45 seconds to get there. Still no codes.

 

Alright, compression test results, cyl 6-60psi, cyl 4, 25psi. Didn’t bother with cyl 2 since it’s not firing on the whole bank. Adding 1tsp oil to cyl didn’t increase psi so rings are good. Didn’t test 1,3,5 because they are the only cyls working. Did a radiator exhaust gas test, got nothing. Valves or head gasket? Cleaning up the garage over the next day or so to get ready to tear into it. I have pretty good mechanical knowledge and am comfortable doing whatever.

 

If you have a bore scope, I'd have a look to see what you can see. Could it be a bad CAM on that side? Out of time on that side? Seems very weird you have 3 cracked valves all on one side.

Rings could still be questioned with such low compression. You'll need to test again after fixing what is wrong.

 

Is there a way to apply smoke to the spark plug hole and see where it comes out? I ask because I don't know.

 

I do have a bore scope I could get ahold of. Timing is spot on. As for having 3 cracked valves, believe me, I’m in awe myself trying to figure this out.

 

I mean I have a fog machine I can pump thru the spark plug hole and find out

 

I was just wondering because I've heard of smoke being used to find leaks in plumbing, etc. So if all three plugs are removed from that bank, then the smoke is applied to the 'bad' cylinder (at TDC maybe?), smoke coming out an adjacent cylinder may tell you something. Coming out the intake or exhaust may point to a valve. I may be reaching here.

 

Just use compressed air with a hansen valve on the end of the air hose. Most hansen valves have a somewhat pointed rubber tip that can be help in the spark plug hole. Listen / feel where the air comes out.

 

You could do a cylinder leak down test, if you have the tools to perform it.

 

When I was replacing these headgaskets at the dealer during the recalls, it was not uncommon to find a burned exhaust valve. Cylinder 6, especially. We had the equipment to do valve jobs, and based on the failure rate that I was seeing, I recommended a three angle valve job on every one I touched. That wasn't any easy upsell on a recall, but I'd say at least 30% of them got the valve job done.

 

Got the bore scope in there, valves are burnt. Started tearing down today. Thinking 1 of two things happened.
1, Buyer of the engine didn’t follow break in instructions and adjust valves after 5k
2, injectors were clogged on driver side, causing lean condition and burning the valves. Then the PO probably changed injectors thinking it would fix, and gave up and here I am lol.
Either way, got a felpro gasket set on sale for 140! Have that, head bolts and a knock sensor on the way. L I’ll start tearing into it more over the next week.

 

Get rid of those Champion plugs. Clearly they were not your problem, but the 3.0's don't like them. Generally the 3.0's only like Denso spark plugs (Denso is what Toyota used) though NGK's seem to do ok too

OBD1 isn't that advanced, it won't register if there is a misfire. Its pretty useless unless something is actually unplugged and even then it doesn't give you the best idea of what to check. I had the ECU temp sensor go out and it didn't turn on the CEL. Had to guess my way through that problem

 

Well, both heads are cracked according to the shop. Any reputable websites to get remanned heads for a decent price?