timing woes

[odie]

trying to get my rabbit running after R&R in the IP is a pain. I marked the belt and pulleys before removing the IP to replace the head seal.

When i put it all back together it was very hard to start and keep running. even have to use a little gas as starting fluid. and lots of smoke.

I noticed the IP pump was rotated a little off of what looked to be the old mounting marks so I lossened the 3 mounting bolts and readjusted and it runs a little better but still hard to start. I think there is supposed to be an alignment mark on the IP mounting plate and the top of the IP but I can only identify what looks to be the mark on the IP, not the mounting bracket that holds the IP.

I'm thinking I should move the IP pully one tooth on the belt, either way and see what happens. Will the car even run if the IP is off a couple teeth? Even one tooth seems a lot to move the timing, everything I've read leads me to believe that a fraction of a degree change (less than a tooth) will have big effects.

[MPalm]

With the cam and crank at TDC you should be able to put a lockin pin in to the IP. The hole is at 12 o'clock IIRC and the pin goes thru the sprocket and the IP bracket and in to the IP.
Move the IP until the pin goes all the way in and it will start nicely.

Btw the IP has 4 bolts, not three, if you are missing the rear bolt you won't get the timing set correctly.

[Vincent Waldon]

Here's a pictorial on the full timing procedure.... if you just move a tooth here and there it may take you a while to stumble on the correct setting:

http://vincewaldon.com/index.php?option ... &Itemid=28

[82vdub]

Typically, white smoke is unburned diesel fuel, which is low compression or retarded timing. If you can't advance the timing far enough that the IP mounting brackets will allow, then you'll have to slip the IP pully a notch or two in relation to the belt, so that you can continue to advance the IP (in relation to the motor).

As for the comment about slipping the IP several teeth, the IP needs to be installed and adjusted (timed) in relation to the cam/crank of the engine, not the IP's physical position in relation to the belt. The IP doesn't care what position it's in, but it does matter in how the engine functions. Is this clear? Just like with installing a distributor in a gasser. Typically, the vacuum advance points a certain direction, but it does not have to point in that direction as long as the distributor is properly timed in relation to the cam/crank in the engine.

[odie]

With the cam and crank at TDC you should be able to put a lockin pin in to the IP. The hole is at 12 o'clock IIRC and the pin goes thru the sprocket and the IP bracket and in to the IP.
Move the IP until the pin goes all the way in and it will start nicely.

Btw the IP has 4 bolts, not three, if you are missing the rear bolt you won't get the timing set correctly.

rear bolt???? oh boy, i better figure this out. there were only the three front mounting bolts when i removed the IP. the car ran fine before. since i don't have a rear bolt can you describe it's location or mounting point or bracket or whatever i should be looking for?

as far as the locking hole...it's straight up at 12 o'clock? i thought it was the hole around 3ish. do you mean to put motor at TDC, lock the cam, then loosen IP mount bolts a little and rotate the IP a little until the pin goes thru? assuming you have the correct number of belt teeth between the cam and IP sprockets (and I don't know that number, i just marked the belt before removing it)

[82vdub]

For these 1.6 motors, the IP locking pin is at about 3 o'clock. Crank TDC, the cam locking plate, and the IP locking pin are for the installation and initial setup of the belt. The final IP timing is done with a dial gauge in the IP, but you can definately time it by ear if you want.

Since you have the timing setup all assembled, you already locked the IP with the pin as you should have. Re-setting up the timing is only going to get to an initial installation point, which you already have. You need to do the final timing of the IP, which is what you're trying to do.

For the IP, there's a nut that's accessible through the front pully, two bolts on either side of the IP, then a bolt (or nut/bolt) that's located under the high pressure end of the IP (by the hard injector lines).

[MPalm]

With the cam and crank at TDC you should be able to put a lockin pin in to the IP. The hole is at 12 o'clock IIRC and the pin goes thru the sprocket and the IP bracket and in to the IP.
Move the IP until the pin goes all the way in and it will start nicely.

Btw the IP has 4 bolts, not three, if you are missing the rear bolt you won't get the timing set correctly.

rear bolt???? oh boy, i better figure this out. there were only the three front mounting bolts when i removed the IP. the car ran fine before. since i don't have a rear bolt can you describe it's location or mounting point or bracket or whatever i should be looking for?

as far as the locking hole...it's straight up at 12 o'clock? i thought it was the hole around 3ish. do you mean to put motor at TDC, lock the cam, then loosen IP mount bolts a little and rotate the IP a little until the pin goes thru? assuming you have the correct number of belt teeth between the cam and IP sprockets (and I don't know that number, i just marked the belt before removing it)

Locking hole at 3 o'clock is correct, I always mix up the TDI and IDI locking holes and pin sizes.
Look at the link posted by Vince Waldon for more about the timing procedure.
Yes, I would put the crank at TDC, lock the cam and move the IP until the locking pin goes in.

[Vincent Waldon]

rear bolt???? oh boy, i better figure this out.

There are pictures in the link I mentioned several posts ago.

[odie]

i printed out your link. i'll take it home and double check the basic settings, TDC, cam locked, IP pin.

but the car should start and run OK it all three are set? regardless of the final timing of the IP with a dial guage?

It seems rotating the pump only changes it a couple degrees, plus or minus. I would think moving the belt a notch would change the timing more than rotating the pump can.

[MPalm]

It should run pretty well with the timing set by the locking tools.

I wonder if you have got the IP 180 degr off, as it rotates at half of the crank speed the crank TDC mark will be at the right spot 2 times during a full revolution of the IP sprocket.
Nah, it wouldn't run at all in that case, would it?

[82vdub]

I wonder if you have got the IP 180 degr off, as it rotates at half of the crank speed the crank TDC mark will be at the right spot 2 times during a full revolution of the IP sprocket.
Nah, it wouldn't run at all in that case, would it?

The internals of the IP can be off by 180 degrees, but the cam and IP sprocket are the larger sprockets and both rotate once for every two rotations of the crank, so this can't be off by 180. If the IP internally is off by 180 degrees, I believe the engine will run, but very poorly and likely very difficult to start.

But, that brings up a good question. Are you sure #1 cylinder was at TDC???

Moving the timing belt one tooth on the IP sprocket will move the effective timing a lot, however, if you can't get it to run right within the normal range of the adjustment allowed for in the bracketry, then you will have to slip the IP by a tooth in the direction you need to get it to go (likely advanced). Just moving it two teeth is probably going to put you one tooth too far, and you'll likely have to go back and slip the timing back one tooth. It's likely due to play in the belt when everything is locked. You just happened to get it on the wrong tooth. It does not take much timing out of adjustment to make these run terrible, or not run at all.

[odie]

the engine will actually run with the IP 180 degrees off? i would have never guessed. i'd think the valves would all be in the wrong position to ensure compression at the point of injection. I'd think valves would be open and the fuel mixture would just get spit out and it would never even fire, or it would fire way early and try to turn the engine backwards or something.

[odie]

i'm guessing I gotta be a tooth off on the belt.

i wish they put timing makes on the cam pulley. all my other diesels have timing marks on every pulley. but i can't find one on the cam pulley...just the IP pulley. but i guess that's because the cam pulley supposedly has no shaft key and can be installed in any position?

[82vdub]

i wish they put timing makes on the cam pulley.

That's what the cam lock plate is for.

all my other diesels have timing marks on every pulley. but i can't find one on the cam pulley...just the IP pulley. but i guess that's because the cam pulley supposedly has no shaft key and can be installed in any position?

That is correct. Apparently, you don't have a Bentley manual to reference. You are supposed to loosen the cam gear and lock the cam position when setting IP belt tension, but...

I don't know if the engine will run with the IP 180 degrees off (in relation to the engine), but it will run with the IP internal components installed 180 degrees off.

When I do my timing belts, I mark the old pully's and belt, remove belt, transfer marks to new belt, then install to match marks on pullys. I've never gotten a belt one tooth off by doing it this way. I've even done it this way and never adjusted the IP after it was done. It ran well when done, so I never adjusted the timing.

[hagar]

Is that Corpus Christi ? and what kind of Rabbit are we dealing with ?


hagar.