Engine wont turn over after setting timing.

[carpenduh]

I just took the top of the motor apart and changed out the cam and accessory oil seals. in doing so I had to reset the timing and it took a bit of time for me to get the correct info, thanks for all that helped. So now the motor is back together but it will only turn over a bit then it seems to bind up. I am turning it by hand so as to not damage anything but I am guessing something went array in my timing set up. Any ideas or suggestions?

Thanks

Gordon

[geospider]

I would first take timing belt back off. check all alignment points. sounds like something must be off.
I have a '79 and know some engines have more of an interference than others, such as your aux shaft; but Bryan will certainly enlighten you on this: he has plenty of early models and knows far more than I

geo
.

[toyfiats]

Depends on the motor that you have in your '70. If it's the original 1438 (or later 1608) then you probably have your cams misaligned, resulting in piston-to-valve interference.

[carpenduh]

It is the original, and i am not sure what you mean by cams misaligned. I took the cams as well as the cover boxes off and the obstruction was still there when turning the motor over.

[toyfiats]

I am assuming based on your first post that the obstruction is only there after reassembling the motor including head and cams. If that is the case then what I mean by your cams being misaligned is just that, they are opening at the wrong time, resulting in them hitting the top of the pistons, thus the binding. You need to take off the timing belt (I am again assuming you are using a new one), reset/realign the cams and pistons to TDC based on the various markings on each, and then reinstall the timing belt.

[carpenduh]

I thought that was the issue and took the cam boxes back off. I still got the binding with the cam boxes removed.

[18Fiatsandcounting]

Gordon, Geo alluded to this above, but what can happen is that the lobe on the auxiliary shaft (for the mechanical fuel pump) can jam against the #2 connecting rod. If that's the case, you were wise to turn the engine by hand first. Some Fiat engines do this, and some do not.

The solution is simple: Time the cams as you would normally, but also "time" the auxiliary shaft. There should be the exact same small hole in the aux. pulley, and you want that to be pointing at roughly 1 o'clock with the engine at TDC and cam marks lined up. It doesn't have to be exactly at the 1 o'clock position, and having it point in the direction of the tensioner pulley is fine. This ensures that the lobe won't hit the rod when the engine is turning.

-Bryan

[toyfiats]

Gordon, Geo alluded to this above, but what can happen is that the lobe on the auxiliary shaft (for the mechanical fuel pump) can jam against the #2 connecting rod. If that's the case, you were wise to turn the engine by hand first. Some Fiat engines do this, and some do not.

Bryan, as an aside, I thought it was only the 2L motor that had the interference with the aux shaft lobe. But it's been too long since I played with the early motors. I never recall having an issue when dealing with my 1608 (which I had apart too often to mention), but was definitely warned about it on the 2L, and in fact that's the only motor I've seen with a hole blown out from when the two met. But in any case, you're probably right.

[18Fiatsandcounting]

Bryan, as an aside, I thought it was only the 2L motor that had the interference with the aux shaft lobe. But it's been too long since I played with the early motors. I never recall having an issue when dealing with my 1608 (which I had apart too often to mention), but was definitely warned about it on the 2L, and in fact that's the only motor I've seen with a hole blown out from when the two met. But in any case, you're probably right.

You've got a good point ToyFiats, and I forget which engines have an issue with the lobe on the auxiliary shaft. Since I am forgetful, I just make sure the aux. shaft pulley is lined up correctly no matter what the engine. Some people that have electric fuel pumps just grind off the lobe on the shaft, which does solve the problem. That always seemed more work than just timing the pulley, but admittedly, if your timing belt breaks, having no lobe would prevent damage in that area.

To check, I suppose you could rotate the aux. shaft pulley to the 7 o'clock position, and then slowly rotate the engine by hand. I believe that in the 7 o'clock position, the lobe will be facing the #2 connecting rod where it can do its mischief. I have a 1438 engine on my bench as we speak, so I'll take a look today.

-Bryan

[18Fiatsandcounting]

Well, I took a look at the 1438 block that I have on my bench. No matter how I rotated the auxiliary shaft and the crankshaft, I could not get the aux. shaft lobe close enough to the #2 connecting rod to cause a problem. It came within 4mm or so, but that's plenty of clearance. These are stock rods, so if there is something "beefier" installed, it might come closer. The lobe is closest to the connecting rod when the aux. shaft pulley mark is in roughly the 7 o'clock position.

So on a stock 1438, Toyfiats is right in that the lobe doesn't hit the connecting rod.

I did play around with different mechanical fuel pumps that I have, and the lever on the ones for the later cars does jam when the lobe pushes the lever all the way (until it jams). My understanding is that the 1438 and 1608 fuel pumps are different than the 1592, 1756, and the carburetted 2L ones. Conversely, if you put an earlier fuel pump on a later engine, you might not get optimal pumping action.

If by chance you put in a fuel pump but it's for the later years, that will cause a jam.

-Bryan

[carpenduh]

I did actually change out the fuel pump, I put this one in and the first time I got it in wrong and it didn't work. After taking it out and resetting it it worked fine apparently up to now.

https://www.vickauto.com/FIAT-PARTS/FIA ... KU-30-5339

I will pull it out and see if that is my issue. Thanks for the info.

[18Fiatsandcounting]

I did actually change out the fuel pump, I put this one in and the first time I got it in wrong and it didn't work. After taking it out and resetting it it worked fine apparently up to now.

https://www.vickauto.com/FIAT-PARTS/FIA ... KU-30-5339

I will pull it out and see if that is my issue. Thanks for the info.

That might be it, so let us know what you find. Depending on the vendor, at least 3 or 4 different fuel pumps are shown for the various model years. Some might work OK, but there are definitely some combinations that can cause problems.

-Bryan

[carpenduh]

So pulled the fuel pump loosened up the cam boxes and took the timing belt back off. turning the motor over by hand I can get to TDC in one direction but shortly after the binding still happens and it will not turn over any further. The same thing happens turning the opposite way, something is still binding at about the halfway point between the combustion and exhaust phase of the number one cylinder. From listening at the top of the motor it sounds like the bind is bottom of the motor? Getting to the point where I may pull motor and trans and drop in a modern 4 or 6 and call it a day...

[toyfiats]

Getting to the point where I may pull motor and trans and drop in a modern 4 or 6 and call it a day...

I'm out.

[ORFORD2004]

call it a day.

Be prepare to have a very long day.