jarheadtex

Ok ...My 86 4runner blew a head gasket. No big deal. I replaced it and installed a new cam and header. I had a hell of a time getting it started. It finally fired and ran good.

This is where it went down hill. I figured U would set the timing, so I installed a jumper. However I put the jumper on the larger of the 2 connectors and it killed it. It would not fire again so I thought I would re-check the valve clearance. I pulled the cover and went to TDC noticed my painted mark on the timing chain was 90 degrees off. I thought "damn my chain jumped" ( not knowing it is only going to line up every 2 revolutions). I pulled the sprocket and rotated the crank independent of the cam to line it back up. Now I have 0 compression on #2/3. I am guessing the valves are bent .

My question is: How can I correct the timing? I did what I though best and put the cam to 12oclock , pulled the sprocket and moved the crank to TDC with #1/4 pistons up and reconnected the sprocket.

Can I just order valves and replace them or should I just upgrade the head while Im down?

FGZ

First, ouch.

Second, what happened in between these two sentences? Did you try to start it, which bent the valves or what?

jarheadtex

I pulled the cover, saw what I thought was a jumped timing chain. Then I moved said chain "back to TDC .Then attempted to start. it sounded like I used roofing tar for oil. That is how hard it was to turn over.

FGZ

Gotcha. And you then pulled the cover again, pulled the sprocket, rotated the crank 90deg, reinstalled the sprocket, and that's where you're at now - getting 0 compression?

I understand it being hard to turn over, but I would have assumed it would just lock up as soon as piston met valve.

I don't have any advice on what to do with the head/cam/valves because I'm too inexperienced, but if it were mine I'd want the whole thing gone through to look for scoring, cracks, bends, etc. And by the time all that happens, a new head with RV cam is in the ballpark of $500 from engnblr so it's a hard call except to say I think you should find something broken before you start fixing it.

And speaking of finding something broken, look for a blown fuse (wild guess) since you jumped the big connector instead of small. Figure out that circuitry before you go much further, so that when it's time to start it again you can at least have that already fixed.

jarheadtex

yeah..I will check for the blown fuse. I think it was that that caused it to die. Then I misdiagnosed the jumped timing chain and bent the valves. I am going to tear into it tomorrow and get parts on order. Its almost beach season ...I have to get the yota back on/off the road!

jarheadtex

YEP!! I checked. The EFI fuse under the dash was blown. So... I thought the timing jumped, the moved the cam timing and bent some valves...hope that is all.

jarheadtex

I just to make sure U get the cam timing right after the repair. I set the can to 12oclock and crank to TDC on compression stroke, then installed the sprocket...so I should be good right??

FGZ

Success! It's sad when "the problem is what I thought it was" is success, but that's how it goes with 30 yr old trucks.

When you tear back down I think you'll see valve imprints on the pistons and then you'll wonder how the bottom end is holding up. I would have that head checked every which way before putting it back on.

jarheadtex

I will let you know tomorrow. I will probably order a new head unless I can get by with just valves.

jarheadtex

YEP! It looks like every intake valve was bent there were marks on 2,3,4 pistons. I had to drive #3 out with a punch. I am getting rather proficient at pulling the head. I guess Ill order a valve set. I really dont want to buy a whole new head...but even though I can do it rather quickly...I really dont want to pull the head again either.

Sturmcrow

You probably already figured this out, but never a bad idea to turn the crank by hand (with a ratchet, of course) to make sure everything is turning smoothly before you try firing it up. In this case, you may have caught the valve interference before causing any damage.

On the downside, you have to have the plugs out for it to really work, and just doing that is a huge PITA on the V6.

jarheadtex

yes...I jumped the gun. I saw my paint mark was not on the dot on the chain and thought it jumped time. I thought "Ill fix this because im super smart" and moved the paint mark back to tdc and fired...or tried to fire it up. If I would have check the fuse this post would be very different. Oh well ...live and learn.

Sturmcrow

Sometimes I feel like I should get that phrase tattooed somewhere.

jarheadtex

Me too! But its true. Hey I was looking for a project when I bought this truck. It ran flawlessly for a year. I enjoy working on it but dont like for it to "need" work.

I ordered some new valves from LCE..Ill get them hopefully before Friday...get them lapped and installed.

FGZ

If you see dings on top of the pistons, doesn't that mean you should check out the bottom end? Maybe the crank and rods are OK, but you at least need to buff down any high spots on the pistons and maybe make sure the walls weren't scored during valve contact.

On the other hand, it's clearly not your only mode of transportation, so bolt it back up and run it. If there is something major wrong, at least you have a good head to put on a new bottom end and like you said you're getting good at slapping that head off and on there haha.

jarheadtex

Yeah, Im definitely going to smooth out the scarred pistons. It is not my only mode of transportation, however beach season is right around the corner(if these weird east coast blizzards stop) and then we roll into hunting season....priorities ...priorities. So yeah, I ordered news valves from LCE performance and a head gasket from RA and Im going to slap it back together and hope for the best. Worst case..the bottom end is toast and I get to rebuild the way I want.

jarheadtex

Well ...Im back up and running!. The valves I ordered were too big!!! So I thought I would just go to the junk yard and get a head. It turns out that they crushed all the yotas. However,!! I told my friend about my issue. He received orders to California and moved. He left his head that he had machined at the machine shop here!!! I just paid the shop $25 and BOOM a brand new head!! I put my EB268 cam in it, put a header on that I had laying around and I gotta say Im really happy with the results. The cam makes getting these 35's moving with stock gears more doable...Now I just need a soft top ..and Ill be ready for the beach!!