Urgent Help request - Timing problem

[Brett]

Hi Gents,

I haven't posted on here in a while, life got in the way of Land Cruiser stuff, so it has taken a back seat for a few years.

Anyway, I still have my 80 series and up until a week ago all was fine with it. To cut a long story short, I was driving to work about a week ago, sitting in traffic idling, went to pull away and the truck starting misfiring, vibrating and kicking out white smoke. I limped it back home and have been investigating the last two weekends.

I've finally found the problem, 6 months ago I replaced the timing belt, idler pulley and tensioner from a well known supplier. My last check today before taking it to the local fuel injection specialist was to check the timing belt. What I've found, the replaced tensioner has failed, leaking oil. This has allowed the belt to jump, it is one tooth out on the IJ Pump pulley when the Cam Pulley is at BDC.

I've removed the belt and tensioner but this is where I'm unclear of what to do.... Is it safe to rotate the IJ Pump pulley back to align the BDC marks, it won't move by hand, so will have to rotate using the centre bolt.

Thanks in advance,
Brett

 

[Dave2000]

If you have the cam at TDC then the valves will be out of the way, so rotating the crank backwards or forwards one tooth will not be a problem. Do not apply turning force on the injection pump, use main crank bolt.

Regards

Dave

 

[clivehorridge]

If you have the cam at TDC then the valves will be out of the way, so rotating the crank backwards or forwards one tooth will not be a problem. Do not apply turning force on the injection pump, use main crank bolt.

Regards

Dave

I understood from the OP that the cam and the crank were aligned, it’s just the IP that’s one tooth out... Brett’s asking if the pump can be turned back one tooth.

Your answer Dave, makes it sound that the IP and the crank are in permanent mesh, and not connected by the belt.

Is this correct?

 

[Towpack]

The IP is driven by the No.2 (bottom) camshaft timing pulley. Can’t see a problem in re aligning the pulleys with the belt off. Just don’t turn the crank or the top cam pulley when they are both set at BDC.

 

[Dave2000]

I understood from the OP that the cam and the crank were aligned, it’s just the IP that’s one tooth out... Brett’s asking if the pump can be turned back one tooth.

Your answer Dave, makes it sound that the IP and the crank are in permanent mesh, and not connected by the belt.

Is this correct?

Yes Clive, crank and injection pump in constant mesh, injection pump drives camshaft via belt, this us why ghe OP cannot turn the injection pump by hand, he is trying to crank the engine.
TDC or BDC the valves will be clear of each other.

Regards

Dave

 

[Brett]

Thanks for the replies gents. I'm still not really clear how I should go about this? With the camshaft pulley set at BDC, what do I need to rotate to bring the injection pump pulley back to the timing mark?

Regards,
Brett

 

[Julian T]

You need to put a socket and power bar on the bolt in crank shaft pulley, the pulley that drives the fan belts for the water pump and alternator, and turn that to bring your injector pump pulley back to the timing mark.
You will probably need a short extension between the socket and bar.

The injector pump is gear driven from the crankshaft and the camshaft is belt driven from a pulley on the injector pump.

Hope this helps.

 

[clivehorridge]

The attached picture (couldn’t find a better one) shows the timing belt only goes round two pulleys, the belt is driven by the IP and drives the camshaft.

This shows that the crank & IP are internally connected meaning that the skipped tooth syndrome puts the cam out of alignment with the rest of the engine.

Aligning the IP timing mark and the cam timing mark will bring it all together, but adjust the position of the IP mark by rotating the crank (only).

If I’m right then hope this helps, if not Dave will correct me won’t you Dave, and tell me to butt out & STFU...

 

[IRLGW]

As you are going to fit a new tensioner you will be safer doing the belt as well. So i would remove the nelt. Reset yourtiming marks and refit the belt..

use a torque wrench on the tensioner bolt next time to confirm you ae not over tightening it. you will be very lucky if it is only the IP tooth that jumped

 

[Towpack]

Turn the crank to align the BDC mark on the cam pulley, remove the belt (make sure the cam pulley doesn't move) then turn the crank the few degrees os so it will take to realign the IP pulley and the crank pulley marks and refit the belt and tensioner.

 

[Brett]

As you are going to fit a new tensioner you will be safer doing the belt as well. So i would remove the nelt. Reset yourtiming marks and refit the belt..

use a torque wrench on the tensioner bolt next time to confirm you ae not over tightening it. you will be very lucky if it is only the IP tooth that jumped

Thanks for the reply, I saved the tensioner and idler from the last cam belt change, these were purchased from Toyota. They are still in good condition and within spec according to the WSM. So I'll use those until I confirm everything is working (or not).

For info, all bolts were torqued correctly last time, that was nothing to do with the failure, the oil seal has failed in the tensioner, losing the oil and thus the tension on the belt.

 

[Brett]

Turn the crank to align the BDC mark on the cam pulley, remove the belt (make sure the cam pulley doesn't move) then turn the crank the few degrees os so it will take to realign the IP pulley and the crank pulley marks and refit the belt and tensioner.

Thanks Towpack, so the general idea is:

1. Rotate the engine by hand to align the timing mark on the cam pulley to BDC (12 o clock position).
2. Remove timing belt.
3. Rotate the engine by hand to align the timing mark on the IJ pump and the crank (where are the marks on the crank pulley/engine?).
4. Refit Belt etc.
5. Rotate again one revolution to ensure timing marks line up.

Thanks again.
Brett

 

[Dave2000]

Thanks Towpack, so the general idea is:

1. Rotate the engine by hand to align the timing mark on the cam pulley to BDC (12 o clock position).
2. Remove timing belt.
3. Rotate the engine by hand to align the timing mark on the IJ pump and the crank (where are the marks on the crank pulley/engine?).
4. Refit Belt etc.
5. Rotate again one revolution to ensure timing marks line up.

Thanks again.
Brett

The engine needs to be rotated twice to get the marks to line up again.

Regards

Dave

 

[Towpack]

3. Rotate the engine by hand to align the timing mark on the IJ pump and the crank (where are the marks on the crank pulley/engine?).

From memory there’s a groove on the crank pulley and a mark on the bottom of the timing cover but I wouldn’t worry too much about those, just realign the marks on the IP pulley when the cam pulley is correctly lined up and the crank will be in the correct position.

 

[Dave2000]

If I’m right then hope this helps, if not Dave will correct me won’t you Dave, and tell me to butt out & STFU...

True, I am known to be a little forthright, but never plain rude Clive. Now get back to studying the FFSM....NOW!

Regards

Dave

 

[Brett]

Bad news guys, it's timed up again but still running rough, vibrating and smoking. End of the road I think.

 

[clivehorridge]

Bad news guys, it's timed up again but still running rough, vibrating and smoking. End of the road I think.

That’s sad news, some bent valve stems I’m guessing, but not the end of the world, surely?

 

[Brett]

Couldn't have come at a worse time Clive, I can't really justify the expense of fixing it, these engines aren't cheap things to recondition are they?

 

[chapel gate]

One tooth out wouldnt cause valve/ piston contact.

 

[Brett]

I've heard that before but it's likely broken something else, I've heard something to do with the cam followers/ rockers can break? Other problem I've also heard (not sure if its true?) you can't source all required components separately from Toyota for a top end rebuild. You have to buy a complete head (new or secondhand).