Timing problems Ka24de...Loosing my mind after 3 days of disappointing results

[lexussc400freddy]

So hears the deal...I have a 96 s14 ka24de...A friend and I took the head off, to be rebuilt. Cost 300 bucks..The valve bucket/spacers was set when we got the head back...Now for the problem...We didn't mark the distributor when we/he pulled it out...I knew better...But some how let him convince me this would be ok...:/ NOW...FAST FORWARD...To time to start her up...No start...I followed the Chilton manual & checked a few threads on the computer...Decided to pull and reset the distributor...This time I felt for the compression stroke to find TDC...The first time I used a long screw driver down the spark plug hole...I KNOW NOW...that was probably among a long list of stupid mistakes...because just because the piston is at the top of it's travel, don't mean it's the compression stroke...We also removed the timing chain guide that is suppose to keep the upper chain from hitting the cover...Per..other things I have read on the computer...SHE STARTED!!! idled just fine..but when I gave her the gas bogged out...I figured..one tooth off...tried re positioning/ still same results...Bogged down when I gave her the gass...Sooo I pulled the upper timing cover...noticed..the marks on the upper chain was Way off...Turned the engine over several times by hand... Noticed the lower cam gear was slipping slightly...How do I fix this? I know upper and lower chains should be aligned some how...Don't really want to pull the lower chain cover...lots of extra work...never the less I tried to fire it up again after placing the top chain right...or so I thought by the 3 marks..& replaced the chain guid...no luck...acts like it's 180 out...like the first time...

[ShadowMan]

maybe this will work maybe not, but off the top of my head this is what I would try. Bring cyl. 1 to true top dead center. Remove valve cover, distributor, and while being very careful, the chain tensioner. Then mechanically rotate each cam individually, probably help to have a buddy there to hold the chain off the gear while you do it. Do this for both cams, then use your manual for resetting the tensioner and restabbing the distributor. This is assuming the chain is set correctly on the crank gear, if its not, then that timing cover should come off to completely reset the chain properly, hate to tell you that but its the smart thing to do IMO. This is an idea from the discription you posted, the call is yours to be made on what your plan of attack is from what you see when you pull the valve cover.

[lexussc400freddy]

This is a thread on what I found and did after some searching on the net..... Fix an incorrectly installed lower timing chain on a 240sx KA24DE (http://www.nicoclub.com/archives/incorrectly-installed-timing-chain.html) (cut and paced if the thread don't show...This got the old girl running again...but...still she bogs way down when giving just a little amount of fuel...I even crossed the fuel lines to see if that was possibly causing the problem... Again Idles fine...Will the timing make it react like this?...I got a sick feeling...The answer is yes...&...The lower cover will have to come off.

[ShadowMan]

I'm assuming you used a timing gun to check everything. I just read that article and if you followed it then it should be good. I dont really know what else to tell you. With the valve cover off rotate the crank pulley and make sure your cams are rotating along with the bottom end. My friend had a similar problem and one of his cams was broken but looked perfectly fine, it was a super clean break, and the whole back half of his exhaust cam wasn't rotating. Check all your head work to make sure its all good. When you took the head off, you didn't let the chain slip at all did you? Because if you did and it jumped teeth on the bottom sprocket then yes you will be removing the timing cover. Got my fingers crossed for ya.

[pacotaco345]

This happened to me after I replaced all my timing stuff. I pulled my motor to replace all my timing chains (upper and lower) and the car would only time to either 28* at the lowest, with the dizzy dropped on one tooth, and to 10* with the dizzy dropped one tooth over from that. I drove it while it was timed at 28* for about a month but it never really ran right and eventually it started to set the knock sensor off when it was given any throttle. After spending 6 months 1300 miles away from my car in college I came back over Christmas break and pulled the motor again to re-install all my timing chains. The whole process only took 2 days, and I put a new clutch in the car at that time as well. Soo long story short, man up and do it right. And invest in a timing gun.

[AsleepAltima]

just for future reference if you dont know if youre at tdc compression or not. stick a towel into the spark plug hole and BUMP the ignition till the rag is blown out of the hole. once that happens, you are at compression.

[lexussc400freddy]

It is possible the lower chain has jumped teeth...I am wondering one lats thought. The lower chain has two yellow marks...One for the idler gear & one for the crank....when I removed the upper timing cover and maid my marks on every thing...(before removing anything)...The exhaust & intake marks was not on the dark gray links on the upper chain...rather between links before the factory marks...Not really an issue..I placed it both ways and it still will do the same thing...Idles fine don't rev over 1100...I'm wondering...now...Is it possible I'm lining the crank gear mark to the dot on the idler baring? Would it even crank and idle? I have noticed...that the factory yellow mark on the lower chain is not lining up with the mark on the idler bearing...And yea...I could of just put the plug wire in the hole and it would of popped out to when looking for TDC..:)

[AsleepAltima]

all you have to do is spin the crank and links wont line up any more. not sure if most people understand that the cams spin twice as fast as the crank and your links only line up every so often if at all once the engine has been spun.

[lexussc400freddy]

The marks on the crank should line up every so often though unless you have spun or skipped teeth on the lower crank gear... There is a certain number of links on the chain between the yellow upper Idler gear and lower yellow crank gear alignment marks. One side of the chain is longer...so it would be possible to have one mark not in place (lower) the one you can't see...If when the dizy was pulled & it was at TDC...(piston fully up)...but not on the compression stroke. That is what I'm thinking...I'm putting The top cam chain in place...But the crank chain is off...Not skipped...marks still align up that we placed...So in other words...think I need to pull the cam gear chain off..spin by hand the engine over till yellow mark #2 comes up...line it up with the dot on the idler gear...or count the number of total links..long side..&..between the factory marks...to determine the placement of the marks with the lower cover on...this is providing the chain was set correctly in the first place and has not slipped.

[lexussc400freddy]

lower-timing-explained, ka24det. Factory Settings - YouTube (http://www.youtube.com/watch?v=jbaFoxm-5lE)

[AsleepAltima]

this is yet another reason why i prefer my sr over my old ka. the sr is so much easier to work on when it comes to the chain and timing.

[CASilForty]

Yeah I realize this is an old thread, but maybe what I have to say has some value. I blew my 94 stage 2 KA climbing Sherwin summit north of Bishop California in the eastern sierras. Anyway, #3 conrod had a meltdown and it cracked my crank and sent the piston smashing into the head and the motor hadda be replaced.

So, I have this worn out old used 95 KA now and I'm in the middle of a partial tear down having just installed a new timing set for the 2nd time. In following the directions specific to the FSM for this task I find that it does matter if your @ TDC and marks are lined up perfectly @ install, but do not expect to cycle the motor after install and have your chain marks align on the first go, they wont! But if you look at the marks on the sprocket, crank and the cam gears, they DO line up at the end of each engine cycle precisely where they should be @ TDC to begin the next cycle. After the motor has been rotated with the timing chain in place, it will not line up with the marks on the chain. I'm not 100 percent sure I'm doing this right, but Im pretty sure I didn't do it wrong twice in a row. This is what I think I know so far, but I'm a long way from putting my Dizzy in and cranking her over to prove it to myself. Having cycled the motor several times though Im confident that there is no interference and that what I think I know as stated here, is correct.:wtf:

[AsleepAltima]

theyre not going to line up because the cams spin at twice the speed as the crank, so the chain is at a different spot once you spin it.

[CASilForty]

theyre not going to line up because the cams spin at twice the speed as the crank, so the chain is at a different spot once you spin it.

AGREED!! And not only that but the chains are not symmetrical in their timing mark spacing either and so cannot align @ the end of every cycle because the lower chain is a good 1/4 to 1/3rd longer than the cycle.

[CASilForty]

.....since the entire length of the chain is not used and slack is taken up by tensioners in the engines design, spacing the timing marks out at even distance on the chain would not work because of the additional slack chain traveling through the sprockets. This is the only way the marks would become synchronized to the chain links. Those links are there simply as a "setup" guide for aligning the valve system to the crank stroke. And, as I've already said, what matters at the end of every cycle isn't the position of the chain, but the accurate location of marks on each sprocket @ TDC, THEY SHOULD ALL RETURN TO TDC POSITION REGARDLESS OF THE CHAIN'S POSITION! ONCE THE CRANK TURNS FROM TDC, Lining up the chain means nothing, what matters is that at the end of ea. cycle, all components connected to the timing system have returned to the ORIGINAL LOCATION YOU ALIGNED THEM TO WHEN YOU INSTALLED THE CHAIN,...... @ #1TDC!!! Provided you didn't hit anything turning the motor to prove this to yourself, you should be on the way to realizing what you need to focus on and quit stressing on your chain as long as your positive you lined all the marks up and the chain links too. Quit moving the crank to prove to yourself you did it right and you wont be so confused!! lol:picardfp:

W/ALL MARKS ALIGNED THOSE CHAIN LINKS ARE NO LONGER RELEVANT AS A REFERENCE POINT, unless ya wanna turn the motor indefinitely to see how many cycles it takes to align them again, but it wont tell you anything you need to know.

But to finish the install correctly, now ya have to realign the whole thing again, chain and all to be sure you drop the dizzy in correctly. This of course does not apply to ppl with a math genius and the ability to count teeth on the fly, or to tune up techs with lotsa experience.

[AsleepAltima]

for dropping in the dizzy, i line up the marks, watch the cams for compression and then make sure the #1 cylinder is at tdc - which it should be if your marks line up and the cams are in compression.

[bmar19]

Dang this is horrible.

[bmar19]

Ok so I'm in the same situation. After reading I assume I didn't go to complete compression idk. I just made sure my lobes were point away from each other at tdc. I left the spark plug in. Maybe I measee up there? Idk I'm confused and I guess gonna take my VC off for a 4th time and try again. My timin is way to advanced cause my turbo heats up fast. This sucks lol

[AsleepAltima]

You can remove the spark plug and stuff a rag in there. Disconnect the coil plug and bump the ignition till the rag shoots out. That way, without a doubt, you know you're in compression. Then you just line up the marks on the pulley.