I will look into the TPS tonight thanks! I m not familar with it or its operation...yet! Checked the gap on the plugs, and put some Lucas treatment into the tank this morning thinking the injectors may be dirty, but to no avail. I am also going to adjust the valves as they are chattering. I am also cuious if the o2 sensor could be bad. For now I will focus on the things that dont cost too much. My wife is becoming less and less a fan of the 4runs project! thanks again Chef.

 

My pleasure, Hertz, .......

Read that link I posted and YOU'LL QUICKLY become familiar with how the TPS works and how to check whether it is or not. I believe he explains how at times one has to check the ECU for a reading as well. You might want to pull the rubber elbow off the Plenum(upper intake) and look at the plate for the 'black goo', also open the throttle and look inside the plenum, it can be LOADED with this goop as well. It's a bit more of a job than checking the valves, but if it's really filthy, you could try tearing down the intake and cleaning it out really well(lots of links on here for that) and while it's apart, you could have the injectors cleaned/serviced/checked for operation at witchhunter.com or rcinjectors.com.(It's about 100$ for all 4 to be cleaned and new o-rings and baskets/filters, to where they're like new). First try the TPS check. I'm not sure the IDL code isn't more serious than just being 'out of adjustment', but it's free and fairly easy to check, so do that first, indeed.

As far as the lucas treament; It's a good quality product, and it can clean things up a bit(most here seem to use Seafoam), but depending on how many miles you have on those injectors, a 'treatment' isn't always adequate. My truck ran pretty well before my build, but when I broke it down, the injectors were pretty filthy, and 3 of them were leaking. My intakes and Throttle body were TOTALLY filthy as well. NOT saying that's what you need to focus on, just expounding on what you're trying.

You may or may not need a valve adjustment, but if you have no problem doing so, it's FREE, so sure, why not check. Just remember/don't forget to put Oil Resistant RTV on the bottom of the half moons if they come out when removing the valve cover. Also put it on the edges of the top(just a dab) of those half moons where the top of the head meets them.(Also, if it's/they're OLD AS DIRT?....you might NEED to replace the gasket if you're pulling the cover. www.engnbldr.com - Ted - is probably the most popular and reasonable guy for that stuff..)

The O2 most likely would be throwing a code if it were bad. Mine went bad due to a CAT with 265K on it and being rich from leaking injectors, lol. But, yes, it threw a code.

Far as the wife? ....Well, I'll leave that alone, EXCEPT to say that hopefully she'll love it when you get it sorted out and take her for a trip to the wilderness with the top off! hehehe.

 

Tonight I decided to adjust the valves. I remove the valve cover and to my horror it appears that the timing chain has jumped 6 teeth since installing the timing chain and cogs. How could this have happened? The chain cogs and tensioner are all new. The passenger side of the chain is tight but the drivers side is slack. Enough to wiggle it back and forth. The truck was hard to start when I first completed the o-haul and it back fired a few times but other than that there was no other time when it made unusual noises etc. can I remove the camshaft cog and simply reset the chain? what would have caused this? The arrow on the right shows the TDC mark and the arrow on the left indicated the link that was at TDC...By the way the tensioner was torqued to spec.

 

Once the engine is run, the shiny links likely no longer line up like they did when initially installed.

 

Oh thank goodness.....Makes since now that I think about it. thanks 4crawler. On with with the valve adjustment!

 

Ok, I am at your all's mercy again. This moring I followed the instruction from the Chiltons to adjust the valves, but the first thing I noticed was that lining up the mark on the camshaft pulley did not bring #1 to TDC. I did not remember seeing this mark when I did the ohaul, and I used the "cotter" pin that is on the crankshaft to align it with the timing chain to TDC. Anyhow to bring the motor to TDC this moring I used the timing gear mark and doubled checked that I was in fact at TDC by pulling the 1st spark plug (this put the mark on the c-shaft pulley way off). I then adjusted valves 1,2,4,6, as instructed by Chiltons. Next I turned the moter 360 degress as instructed to adjust 3,5,7,8 but these valves were all at the top of thier stroke making it impossible to adjust them. I guess I have screwed up royaly somwhere???

 

FIRST OFF; DO NOT START IT YET!

I'm in NO WAY trying to argue with 4Crawler, ....the guys an engineer for goodness sake! lol. However, my motor had 258K miles on it when I tore it down, ....and when turning over the crank by hand, it lined up on the 0(tdc) and the shiny link at 11:50 over the lil mark(Cam Gear Hole-larger mark- right at 12). Sometimes you have to come around 4 times in order to get the Crank at TDC and Shiny Link at 11:50, with the #1 pushin out the top. It takes multiple turns of the crank to make a full turn of the cam(4 turns, Crawler? Anyone?)

Secondly, at 6 teeth off, I'm not sure it would run, and I would think you'd be bending valves and such like crazy.

Just take a breath, Hertz, and I'm sure it'll get figured out. Lemme read up, but are you ABSOLUTELY SURE you're at TDC on the 'COMPRESSION STROKE' with #1 plug forcing your hand off the plug hole? I was initially a lil freaked out when first tearing my motor down, but then it eventually came around and everything lined up when turning the crank.

 

Yes, those links can be lined up again, just a function of the teeth on the crank gear and the links in the chain. Given enough turns, yes, you can line them back up. My point was that on a random stop of the engine, the chances of them being lined up are not great.

 

As you can see, when I tore it down, both pics are at the same setting. Crank at 0 and Cam Gear Mark at 12-with shiny link at just left of it(my shiny link was actually over a hole right under it. Second pic shows that. This is more easily verified because you have the Valve Cover off, ya know?

 

Right, I hear ya 4Crawler. I just wasn't sure he knew what you meant. Especially if the valves weren't adjustable in series like he found. Each time I had to verify this, I'd pull the #1 Plug, then I actually had someone watch while I tapped the starter with the coil wire off and grounded. I kept tapping it until the Crank Mark hit 0 and his finger was pushed out of plug hole #1.

Roger, ...You think he was on another stroke when he first adjusted the first set? How to remedy this? (First get it PROPERLY on TDC with Cam Gear proper, then re-adjust the exhaust valves, ...then the intake should be loose on the next stroke???)

 

Hertz; ...Also, you can make sure while you're in there, ONCE YOU GET IT LINED UP RIGHT, that you're at #1 on the Dizzy with the cap off(making sure the lil notch in the dizzy gear is just left of the cam gear).

 

Hertz, in this picture you provided in this post(sorry I missed it the first time), you are CLEARLY OFF by at least a full turn of the crank....and in fact, it looks more like around 3 FULL turns of the crank are needed to bring it back to TDC with the shiny link at 11:55(whatever, lol). I misread your post, 4Crawler, I apologize. However, I think Hertz misread it as well and then went on to adjust his valves from where the marks were in the pic(is that so, Hertz?....Did you adjust the Valves with the CRANK at 0 on the Mark and your cam gear where it is in the picture?)

 

Hertz, ...... I would recommend you repost your symptoms in a 1. 2. 3. list on top of each other, things you've done and checked/verified, and then, post EXACTLY where the Crank and Cam gears were when you began to adjust the valves.

 

Great work Chef!

Hertz - be patient and don't freak out - we've all been there (and I'm there again right now). I thought I'd slipped a tooth when I took off my timing cover recently, and I then realized that you had to turn the crank multiple times to turn the cam once and line up to TRUE TDC.

They guys here are great and can help walk you through this, just like Chef and Roger are - just be sure to list ALL your symptoms and tactics as you go, and photos really help.

Best of luck - hope it turns out well and soon!

Phil

 

Hahhaha. Heck, it's MY PLEASURE, after all the help I've received. It can be SCEEERY! lol. Seriously, it can, when first tearing into one of these. VERY important to mark everything properly, get the nuts and bolts and studs back in the same places if you can.... And even then, we tend to want to move forward when NOT SURE of something, lol. In the end, it's all worth it! hehee. Hertz'l'get it. He's got the drive and he's almosttttttttt there, lol.

HOWEVER>>.....this portion of the "Wrenchin" is CRUCIAL that everything is JUST SO! So be sure to do what I said, Hertz....take a breath, start over fresh with an original description of the symptoms, then what you found next, then adjusted, replaced, etc., etc., ...and then you'll be more likely to even get some fresh perspectives. ....People are busy, ya know? Hard to jump in and read back through to figure out a likely culprit and maybe solution.(Especially now that you're officially an "OH CRAP" thread with 3 Pages and counting! hahaha. Jk, inside joke).

 

Oh Crap..yes correct! I think I know what is gong on here. It is my ignorance of how an engine works...I am good at directions and with tools but lack a basic understanding of motor functions. When I installed my t-chain and gears, I aligned my camshaft key staight up with #1 at TDC. I then put on the gears and chain and aligned the top gear dimple straight up with the shiny link staddling the dimple tooth (think this is where I screwed up). I paid no attention to the mark on the camshaft pulley because i could not see it and Chiltons made no mention of it. SO in the end I lined up incorrectly on a ehaust stroke..I think? I calld Todd at ENGNBLDR (great guy!) and he explained that this happens a lot because to book is unclear. He explained that i need to turn over the motor until I get the pulley mark on "0" to achieve TDC then remove the top t-chain gear and align the dimple with the triangle on the rocker arms. At that point I should be back on time. Does this all sound correct?

 

See the pictures I posted? That is at TDC on the Compression stroke of #1 Cyl., w/the Crank Notch at "0" and shiny Link JUST left of the 12'oclock position on the Cam Gear(The Main Dimple/hole/Arrow in the Cam Gear, at this point, SHOULD be at 12'oclock with the shiny link/smaller hole-dimple just under said bright link right at 11:55 or whatever you'd call that) THAT IS DEAD ON TDC. It just takes time to get the Crank turned enough times to get that link to come around to just left of the top. BEFORE you pull the chain, etc., ....put the Crank on 0 and make sure #1 is at the top/dizzy at #1 too, and take a picture if you can of where the shiny link is in relation to the Arrow on the Cam Gear(again, should be JUST left of it on the next tooth over).

 

This has been an interesting day. First I thought I had really screwed up, but after talking with engnbldr we found that the marks on my harmonic balancer must be off or have gotten moved or shifted sometime in the trucks past. Anyhow that issue has been resolved and I have now successfully adjusted the valves. I could go on about the timing issue but it is a lenghty story and in short..the 0 mark on my pulley does not bring the motor to TDC. Luckely when I installed the pulley (with Key facing 12:00) I marked the pulley. his morning I tried to adjust the valves using the 0 mark and there in lies my problem. Soooo valves adjusted! Good idea Chef, I will post a summary on this now lengthy thread.

 

Thread Summary:
I have an 1986 4runner I bought with a failed timing cover. truck was not running. So far I have replaced the timing cover, chain, chain gears, head gasket, head has been decked and checked, new hoses.
After the ohaul the truck ran great after getting the timing right. It idled great and ran better than the previous 2 4runners I have owned. I took the truck on a 40 mile test drive. It ran perfect until I almost got home. When revving the motor at high RPMs the motor falls flat on its face. It is almost like having a rev limiter. When the motor is cold I can drive it around for about 30 minutes or so before the problem becomes so bad that I can barely put my foot on the gas before it stalls out.
So far I far done the following to try and fix the problem:
New Fuel pump, fuel filter, adjusted the valves, ran lucas oil treatment through tank, New plugs/wires, replaced PCV valve, checked and rechecked for loose connections.
Tonight I removed and checked the TPS (throttle positioning Sensor) and will check it in the morning at Auto Zone.
There are many threads dealing with similar issues. The problem is that most of them are open ended with the threader never revealing what the problem was. I am finding out that this is a fairly commong issue, and I will post until I find the problem and SUM it up for future readers to learn from.
Any suggestions are very welcome!

 

ehertz: Couple questions if I could

You said you purchased this truck with a bad Timing cover.

Was the timing cover bad becaus the Timing chain had broken it's guide and warn through the cover?

did the motor "Milkshake" ?