Kevin B's 1985 4Runner

sixstringsteve · Nov 21, 2012

man Kevin, I really feel for you. Best of luck man. Let me know how I can help.

Kevin B. · Nov 21, 2012

TRD270 said:
One more possibility is you could have lost a valve seat, this happened to my cousins 4 runner several times. I think you would hear a lot of noise if this was the case though

It ran rough, but I didn't hear any abnormal noises.

sixstringsteve said:
man Kevin, I really feel for you. Best of luck man. Let me know how I can help.

Thanks Steve. Got a mechanic who works for free in your back pocket? I could really use one.

Incidentally, the gas in there is definitely bad. I've never smelled bad gas before, but it has a sickly sweet smell to me, and my wife wanted to know why my truck smelled like paint

. So I'll be draining the tank, replacing the filter, and having the injectors cleaned as well.

Please don't let it snow this weekend.

sixstringsteve · Nov 21, 2012

Well, I'm not a mechanic but I do work for free.

Kevin B. · Nov 21, 2012

Thanks, Steve. I was planning on snowboarding this weekend, but it looks like I'll be wrenching instead. Company would be welcome, but that's a ways to ask you to drive.

I've got the head from the '86 that I think is fine. Can anybody recommend a good shop in Magna/West Valley to inspect it? If I'm going to pull the head and redo the gasket I may as well have a head I KNOW is good to put back on.

sixstringsteve · Nov 21, 2012

I will be out of town this weekend, but I can help next week.

clfrnacwby · Nov 21, 2012

Put the crank at TDC (top dead center). Grab a partner. Shoot air into cylinder #2. If it leaks out the tail pipe it's your exhaust valve. Air out the intake, intake valve. Air out the oil dipstick, bad rings. If there is no obvious noise then you might be looking at a broken valve spring.

frieed · Nov 21, 2012

Excellent tip....makes all kind of sense

Kevin B. · Nov 22, 2012

Yeah it does, thanks Andrew! I'll check my air fittings in the morning and see if I can set that up.

Kevin B. · Nov 22, 2012

I dropped a small glug of oil in the cylinder, and tried the compression test again - still zero, the needle doesn't budge. I fired up the compresser and stuck it on there - I can't detect any air coming out of the lower plenum (the upper is removed) or the exhaust, and the PSI on my tank doesn't drop at all. I have to think that if there was a loss of compression so bad as to cause 0 psi on the gauge, that it would at least drain my tank fast enough that I could detect some needle movement over a minute or so (this is a tiny little 3 gallon hobby compressor). I think this compression gauge is flaky.

But there was the popping sound at the exhaust - bad valves, or just weak little backfires from unburnt fuel making it into the exhaust? And it did seem to even out a little and stopped the popping when I squirted fluid into the the intake.

Knowing all that, and KNOWING that there's bad fuel, and time being of the essence (I need this truck running next week, and would really rather not have to wait on a machine shop to check out my other head), would you pull the head anyway? Or would you just drain the gas, change the filter, swap the injectors with your spares from the '86, and button it up and hope?

frieed · Nov 22, 2012

I'd go in steps with the easiest or known problems first.
If the gas is known bad, then drain, purge, change filters, and refill.
Try firing it up again.
If the problem remains, maybe some sea foam, then swap injectors and hope.

Kevin B. · Nov 22, 2012

That's where I'm leaning too. I'll do the injectors, because I've got the plenum off to get access already and there had to be something making that cylinder not fire, and then we'll see what happens. If it still won't fire I'll take it to my mechanic and pay him to point me in the right direction, but I'm really not feeling like paying a machine shop to check out my head, plus another $150 in gasket and head bolts and oil just for a head that might be bad but probably isn't.

I need to go take some community college auto shop. I really wish I had a little more authority under the hood.

sLcREX · Nov 22, 2012

How is the timing? Have you checked that? Could be a reason for the rough running condition, also I remember once on a honda motor I didnt set the timing properly and I was registering like 30 PSI and I thought I had ruined the motor but the valves just werent opening at the correct time letting all the compression leak out. After I corrected the timing my compression was right up around 130 or so, big difference. Might be worth taking a look at that.

frieed · Nov 22, 2012

Mal,

When I think timing I think spark advance.
are you talking maybe the timing chain jumped a tooth, assuming overhead cam.

But wouldn't that affect all cylinders?

sLcREX · Nov 22, 2012

Yeah I'm thinking a timing chain jumping teeth. Things could be differeing since it's a single overhead cam motor, this happened on a dual overhead cam and it affected all cylinders but not by the same 100 psi drop in compression, some were 30, others were 90, another 140 etc, they were all over the board.

Kevin B. · Nov 22, 2012

Nah, the timing is good. I messed around with it before I pulled the plenum and valve cover, and it was right around where it should be. If it was a tooth off it'd be like 30 degrees one way or another, if I remember right.

frieed · Nov 22, 2012

My main experience with timing is getting all the sides on the table at the same time as the turkey...

Kevin B. · Nov 22, 2012

Fuel filter changed (and relocated to the fender, no way was I going to try and maneuver the new one back onto the side of the block with my giant numb hands, what a horrible horrible location for that) and injectors pulled. Taking them in for a rebuild and balance tomorrow - I thought about sticking my spares from the '86 in there, but decided not to cut corners.

Kevin B. · Nov 23, 2012

More pics!

Fuel filter relocation. I highly recommend this, the stock filter location is garbage and an utter PITA. This required no mods, the hoses will reach. I unfastened an existing bolt on the firewall and bolted the filter down. I'll add a bracket from the other side of the filter to a lower spot in the firewall just to prevent vibration fatigue on the one side.

And, I found my next project on this beast. Still s curved at full droop, and a broken leaf to boot. I didn't want to buy suspension yet, but I can't drive around on that.

As much as I gripe, I'm still having fun with this. It'll be a lot more fun when I get it on dirt, but I'll have earned it.

Kevin B. · Nov 24, 2012

I'll be really glad when this stops being "KidV's repair thread" and starts being "KidV's build thread".

First, a public safety announcement:

NEVER EVER TRUST A HIGHLIFT

I guess I didn't have it straight up and down, because the bottom kicked out away from the tire. Luckily I have another fender, and I was planning on painting the whole truck a rattlecan grey once I repair the rear fenders anyway, so this is not horrible. Scary, yes. Don't trust the highlift, people, it will eat your face.

I don't know if this engine ground was making the truck run worse, but it sure wasn't making it run any better. I'm much happier with it's 6ga replacement. Once I'm done with the have-to-fix's and can get on the want-to-upgrade's, I'll replace the entire battery cable system.

The original owner thought he was getting more air, I guess. I think he was getting more road spray. Luckily I have a parts truck 20 feet away - having the '86 sitting there has saved me so many trips to the wrecker.

Thermostat plug? Is that what wire I broke here? Disappears into the harness, so I see some splicing in my future. I hate splicing on my harness.

Spork · Nov 24, 2012

Wow that's a trick with the hi-lift... I think you ought to invest in a bottle jack.

Kevin B's 1985 4Runner

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Jeepless in Draper

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Jeepless in Draper

Not often wrong. Never quite right.

Not often wrong. Never quite right.

Not often wrong. Never quite right.

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