Urgent Help Needed: Misfires after VCT replacement & Timing chain refresh
 

Vehicle:2007 lr3 4.4L
So I thought I just finished repairing the VCT cold start problem and refreshing the timing chain, but it appears I failed somewhere along the way.

I replaced all the timing components, except the actual VCT solenoids.
Bank 1 is where I think I had the VCT cold start problem but I replace both sprockets anyways.

I had no codes before the repair, but the start up banging had gotten really bad.
Follow the service manual exactly.

So the car will star but it runs kind of rough. It is spitting out a the following codes:

P0301,03,05,07: Cylinder 1,3,5,7 Misfire
P0300: Random/Multiple Misfires Detected
P0316 Engine misfire detected on startup
P0016:Crankshaft Position-Camshaft Position Correlation
P0026:Intake Valve Control Solenoid Circuit Range/ Performance

So I think that means it is confined to one bank.
But can anyone think of anything before I dig back into the engine? Could the solenoid have actually gone bad? I wasn't getting that code before the repair.

You sure you got the cams timed properly?

Yeah, Bank one timing is off.

That was what I had assumed. Just wanted confirmation that there wasn't something I was missing.

Follow up question.

I noticed that after I had tightened down the sprocket bolts on Bank 1 then removed the "special tool" that the secondary chain would go a little slack. Now when it was in the tool the chain was nice and tight, but the second i would loosen that tool, it looked like the exhast cam would turn clockwise just a little. Now I had noted something like that when I took it apart, so I didn't think that was an big issue. but does anyone know if that sound right?

Is the secondary tensioner new? It should not move after timing is set.

What he said

Abran,
I thought that I had the tool issues, I have since ordered the more oem type tool.


Yes the seconday tensioner is new.

Stupid question time. I have never set timing on this engine, but I assume the procedure it like all engines. You set the timing with the tools, then you crank the engine manually several revolutions with the tensioner loaded and check/adjust the timing again - repeat until it comes out exact consistently. Right?

Set it once and done.

I dont think I could do that for the very reason this thread exists. Its contrary to every engine I set timing on, odd!

That would appear to be right. I had one of my cam covers off a couple of weeks ago to check out the VCT solenoid. I noticed that, though the secondary chain was properly tensioned, it was slack at the top between the two cam cogs. I had quite forgotten about this slack and am sure it was there after I rebuilt both my heads.

On the point of setting the timing, are you aware that there is a shim (sold by Dingocrft here in the UK) part Nº 303-530-04 that sits between the the cam locking tool and the two flats. I had one for my rebuild, it takes up that small gap left between the flats and the tool and locks things up better. https://www.dingocroft.co.uk/cgi-bin...303_2d530_2d04

https://cimg3.ibsrv.net/gimg/landrov...6baa05d492.jpg

Yeah, the AST tool comes with it. The cheap tool I had would have needed 4 or 5 of those.

https://asttool.com/detail_page.php?...&from_search=y

So when I got the covers off the intake sprocket was off by 15-20 degrees. I have followed the topix shop manual exactly, used the crappy tool, but nailed the torques. I thought I had checked this before I closed up the engine. Does anyone have any thoughts about how the timing could have gotten this bad without me just screwing up?

Here it is:

Tmingi chain and tensioner replacement

Thanks for posting that resource! I am considering doing my own timing chain/tensioner service as I dont want to pay the shop $7000 for the job. Your resource is amazing! Thank you!