need help with weird engine issue

S

stackz

New member
just going to give full history.

ok, 97 4runner with 5vz-fe engine. it blew the head gasket and cracked the head on the passenger side #1 cylinder.

during compression test, we didn't know. I had the compression gauge in driver #1 and we turned over the engine. coils were just sorta sitting to the side. water shot out pass #1 and there was a random "pop" noise.

anyway, pulled engine down and replaced the head. got it back together and it will run good and idle fine and then you can rev the engine and it will start a random weird popping noise and that's when it runs rough and spits smoke that smells like gas.

pull the plugs and the driver side ones are all dry and nice but the passenger side ones (with the coil packs) are gas wet. its like its not firing on the coil pack plugs...makes no sense. the driver side plugs run off the coil packs on the passenger side...

also, I cannot for the life of me pinpoint the popping noise??

was going to take a youtube video of it in a bit but wanted to post anyway in case the day (football) got away from me.
 
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no, its not a clogged cat.

and it wasnt symptoms of a bad head...the head was actually bad. passenger side #1 cylinder blew the head gasket and cracked the head between the valves.

this issue has popped up upon first crank up after getting it back together.

I almost wanted to say something was bumping around in the engine but thats not it as by now it would have caused a catastrophic failure.

Also, it wouldnt cause the entire side's spark plugs to be drenched in gas.

its gotta be something electrical I just wish it would hurry up and fail so I could pinpoint it.

going to take video this afternoon and try to see if there's any codes or not.
 
Most likely, theopping sound is the gas (from the pass side) detonating in the exhaust which is why it smokes and smells like gas.

As to why you're not firing on the pass side, I would double check that the coils are seated firmly on the spark plugs. If they are then my next step would be to find a fsm and look fora test on the coils to make sure that they're working properly.

Did you put new spark plugs in?
 
very well could be.

no, I didnt put new plugs in. dont want to foul out new plugs.

I thought the coils might be making bad pickup as well. I pulled them out and pulled the center portion off each, put dielectric grease on all contacts and put them back in.

ran great for about 3 minutes or so (no cranking/running rough issue). then I revved the engine and it started back with the issue and has done it the couple times I've ran it since.

when it was cranking/running fine, no popping issue, makes sense it could be the gas/backfiring, etc.

what has me going "wtf" is the driver side plugs/wire run off the passenger side coils, I wouldnt expect it to run at all if the coils were failing but I have good rich burn on the driver side plugs.

is there a secondary ignitor I should be looking for possibly?
 
What do the pass plugs look like? Are they old and dirty? As cheap as spark plugs are, it's good insurance to just use new ones.
 
plugs look at have low miles on them. aside from being washed out with gas they look just fine, the electrodes arent even showing any wear yet.

Also, after I pulled them initially I went ahead and swapped the ones from the driver side to the passenger side before running the engine again.

was going to pull them today and see if the ones in the passenger side (the old driver side ones) are now gas washed while the ones that were in the passenger side have carbon now built up on them.

I did grab another coil and a couple boots from the u-pull on saturday as well. I want to ohm the coils to make sure they are all good but cant find a test procedure to follow
 
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injectors were never messed with. I pulled the whole lower intake as a unit with injectors in place.

after reading around online and looking at the engine diagram, I'm more and more thinking the ignition control module (ignitor) might have been what made the popping noise when we were doing the compression test initially.

makes sense to me that the primary side to the coils would then be dead and the secondary side still active (causing an entire bank to be dead all at once).

I havent had any luck as of yet finding a test procedure for the ignitor though. I did buy new plugs at lunch that I'll toss in and then test the coils as well...and the 12v+ input to the coils.

the test I found has the primary side at .6ohm cold test and secondary side at 9.3k-ohm cold test.

this doesnt sound right to me?
 
going to follow the ignitor diagnostic I found here:

http://www.toyota-4runner.org/3rd-gen-t4rs/20243-igniter-failure.html

will probably do this first after trying to pull codes...especially if it doesnt give me any codes.

more and more thinking this is what happened. we had all the plugs out to figure out which cylinder the head gasket blew on. already suspected #1 as the plug was wet, duh. but still wanted to make sure I didnt have to pull off the driver side head as well. I had the compression tester in the first hole on the driver side head and spun the engine over.

water shot out of the pass #1 hole and I heard a loud pop noise. just decided to stop there and pull the engine down. got it back together and it runs fine except the issue I'm having.

found out the ignitor is over by where the MAF sensor is...thats right where the water shot to...kinda helps me focus on the ignitor at this point.
 
ok, had to get stuff done at work yesterday, only to get furloughed today...thanks congress...

anyway, I stopped at the pick-a-part yard and grabbed two compatible ignitors...without doing any of the testing that I wanted to.

first one, same symptoms.

second, it cranks and runs each time now. it still smokes and makes weird noises but finally gave me codes.

P0300, p0301, p0303, p0305 lol, makes sense. its the random misfire code plus the ones for the side that...wow...isn't firing. which is the coil side. lol.

I'm going to let it cool down and then pull the plugs and read them. obviously they aren't fouled as I'm not getting a 0302, 0304, 0306 code after swapping plugs. I'm going to stretch the coil pack springs thinking I'm not getting full contact and try some other stuff and report back.
 
ok, been getting a bunch of projects done the past week that I've been putting off since I haven't been working lol.

finally got back to the car yesterday and I ran a bunch of tests on it. I checked 12v+ at coils. good.
checked resistance on both sides of coils. good.
checked cam/crank sensors. good.
double checked the timing components. good.
I also did what others suggested on various threads on here and pulled on the coil plug springs to stretch them back out. got good results on two and pulled one out completely (oops!)

I'm still looking up the info on testing the ignitor and the wiring at the ecu and will check that as well.

I pulled all the plugs and cranked it over and then put a flashlight down all the holes. there wasn't any water in any of the cylinders (was beginning to think there was a random headbolt that needed sealant...or the deck was warped which I didn't check), just smelled gas. driver side plugs all still looked fine, passenger ones were still wet with gas.

I cleared all the codes and cranked it back up and let it warm up. shut it off and let it cool down and then cranked it back up and warmed it up again.

both times it would stay at around 1400rpm and it had the same smoke. second time it actually stopped smoking mostly, just giving occasional puffs here and there and every now and then a cloud for a bit. ran smooth but never idled down, never ran hot. anyway, check engine light finally came on. shut it down for the night.

just went out a minute ago and cranked it up again. it was back to running rough but the only code it threw was a p0303 instead of like last time where it tossed the generic code and all three cylinders on that side.

I'm going to let it finish cooling off and then go pull the back cylinder and see if that's the one where I pulled out the spring or not (I just sort of shoved it back in hoping after all this that would be the one cylinder I would still get a code on haha).

I'm also going to pull the other two and see if the plugs look any better.

I did check spark manually on all cylinders and I was getting spark at each. it wasn't what I would consider "great" spark...but it was spark.
 
ah god...that's what I get for not doing a compression test before tearing the engine down.

excellent compression on the driver side and 0 on the pass side. know I don't know if the rings on all three pistons are dead. unlikely but it would be my luck.

its not burning water very bad at all if it is as the smoke isn't that bad and is mainly fuel smell.

that leaves the valve train and/or rings.

all I can think is the timing on the valves is off and I may have bent some....or the rings could be bad if this is not the case.

I'm really hoping this is a non-interference engine.

going to borrow my neighbors videoscope and leakdown tester to do a visual and overall test before I tear this engine back down again if the rings aren't gone.
 
is the 5vz-fe engine an interference engine?

I did a leakdown on the cylinders and its coming from the exhaust at tdc on #1 cylinder.

I pulled the valve cover and looked and at first glance it doesnt look like the valves are bent but you cant be sure yet.

I also noticed there are two sets of marks on the cam gears and I have the single intake cam gear mark lined up with the dual marks on the exhaust cam so I assume the exhaust cam is lined up 180* out...sigh.

didnt notice this the first time :ybrick:

I'm wondering if I bent the valves or not or maybe I'm just really lucky and need to realign the exhaust cam...
 
god I'm hoping having the exhaust cam 180 out doesnt mean the intake and exhaust valves made contact at any point...
 
Suprised no one has answered the question yet. The 5vzfe is a NON interference engine
The pistons will never contact the valves in any event.
 
I agree! lol.

anyway, I found through a couple google searches that it wasnt an interference engine before you posted.

also, I setup the old cracked head and junkyard cams (was fun getting the exhaust cam setup properly as it wasnt locked when they pulled it)...set it up the same way I had the installed head setup and the valves didnt contact so I pulled it down and popped the exhaust cam back out and aligned both cams with the double marks...rotated, reset the timing belt, put it back together and it runs just about perfect.

it wont come down to hot idle which I think is either the computer still learning or I have a vacuum leak but I'm very happy that I have 175psi + in each cylinder and its running really really nice.

once I get the high idle figured out I can finally give the car back.
 
Glad to see another runner from Charleston posting on here! I'm having a lot of the same issues you are, or maybe I will be having the same issues.


I had a random misfire, and cylinders two and three misfiring a little ways back, so I replaced spark plugs, wires, and coil packs, only to find I had the same issue. Reluctantly went down to the dealership and paid $60 for them to "run tests." Bad news bears. I have 0 compression in cylinder three. They wanted $1200 to pull the head off, then maybe $1200 for a new set of valves, or $6-7k for a new short block installed. I drove out of there as fast as possible after consulting some friends and T4r.org

Not really trusting what I learned from the dealership I bought a compression tester from Harbor Freight and we attempted to compression test it. We could only get the threads in about 3/4 of a turn and thought that was odd, but we pressed on. We got about 15 psi and holding.

A trip to Advanced Auto later and we had a thread cleaner/reamer and we ran that down to full-stop and came out with two little pieces of metal. Upon attempting to put the spark plug back in, it turned the same as before, only about 4 turns. Other spark plugs? Same story. Even plugs that had never seen that cylinder before.

We set out to do a wet test and pour oil into cylinder 3 and attempt to get the compression tester back onto the threads and can NOT get it. We can hear it touching the threads and dragging across them, but it will not grab at all. Put it all back together with plans to pull the head next week. We may be buying a new valve if there is a hole in it, or an entire new head.

This is also pretty much the cliff notes to the story. The real story is much more fun involving buying the wrong tools, wires put on wrong, being towed, running out of fuel on the side of the highway on the way to get more tools, Welding, Grinding, and some blood, sweat, and tears in there too.
 
odd you could only get the tester down in the plug hole with 4 threads even after you reamed it out. sounds like the very top threads on that plug hole are torn out so you cant start it properly.

you shine a light down in there to get an actual look at it? you could have a burr sticking out possibly.

just remember to put a bolt in the exhaust cam before you take it out or you'll have to toss the cam in a vice and pry the inside of the gear back over to line it back up before locking it in place.

also, definitely line up both cams with the twin dots which will have it 180 out from TDC. this is the mistake I made. I see why you do it this way as with the bolt in the exhaust cam, it will hit the head casting trying to do it the other way. you just rotate it after its all in place and the bolt it out before setting up the timing set.

oh yeah, and dont pull the exhaust manifold if you can help it. the crossover sucks so I didnt even mess with it. I just pulled the nuts off the exhaust studs and then pulled the studs with an 8mm socket. much easier this way.

also, if this is a vacuum leak I'm dealing with, it likely at the valley of the lower intake where the factory had some goofy foam type gasket that rotted away. I used a thick bead of silicone on front/back but I'm wondering if that wasnt enough to completely seal it off.

I know your location says jacksonville but if you are still in charleston, blue/gold has a couple heads for sale if yours does turn out to be bad. I also saw a couple 4runners in this year range at the u-pull but got my head from blue/gold instead so I didnt have to deal with pulling it and dealing with the exhaust studs.

if all you need is valves I'll just give you the old cracked head, the valves are still good in it. I cant for the life of me see any of yours being bent though with this being a non-interference engine and the valves will never contact each other. trash in the cylinder is the only way I could see them bending...especially after I had this truck running several times to operating temp with both valves opening at the same time due to cam phase lol.
 
back on target now after googling "4runner idles 1500" and reading through threads it seems the TPS or IAC can cause this as well as the obvious vac leak which I'm unsuccessful at finding at this point...if thats the case. also, the MAF can cause this issue.

I'm in the middle of looking up the specs on the TPS and IAC and I grabbed a new can of carb cleaner to check for vac leaks some more sigh.

I'll look into cleaning the MAF as well this afternoon. With the cracked head issue originally and the water that was in the intake pipe, it could be likely that the IAC is gummed up. doubt the TPS but maybe the MAF is dirty from the oily water that was in the intake tube as well.

I've reset the ecu and ran it a couple times to operating temp and it stays at 1500rpm all the time so I doubt its an "ecu learning" issue.
 
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