ignition timing is 180 degrees off

[MrShorty]

Decided I wanted to check my engine timing for fun. Disconnected the SPOUT connector (little connector with pink wires next between the a/c evaporator housing and the ignition coil). Hooked up the timing light to #1 (passenger front cylinder), pointed it at the timing mark, and couldn't see the 10 degree mark on the crankshaft pulley. Crawled underneath with the timing light, and there the crankshaft mark was, about 180 degrees away from the timing marker. Engine runs fine. What would cause the engine timing to be 180 degrees off? I recently had a rebuilt engine installed, is there something that they could have installed wrong that would cause the timing to show 180 degrees off?
TIA for your help.

 

[AlaskanJack]

Well first not all cars are timed using #1 plug. But the way the timing is set on the 4.0 is with the cranckshaft and camshaft dots in line and the timing chain lines up with them. So I don't see how it could be 180 off unless the pulley was installed upside down on the camshaft.

 

[Robb]

If you were 180* off, wouldn't it be sparking with the exhaust valve open, and therefore have no compression, and therefore no ignition.........................therefore not allowing the engine to run?

 

[JDraper]

Try hooking your timing light up to the driver's side front cylinder.

 

[MrShorty]

Thanks for the responses. Here's what I've done to date.
I went to the library and searched through the '92 Mithcell manual and found very little.

Disconnected the SPOUT again and hooked up the timing light again. Tried all six cylinders to see if anyone of them would fire at the "correct" time. None of them fires when the indicator is pointing to 10 degrees BTDC.
Called the shop that installed the engine. He confirmed (as Robb guessed) that an engine won't run at all if it's truly firing at 180* off. The engine is running quite well, so I don't believe it really is firing at 180*.

Asked him if it would be possible that something were installed incorrectly. He said, "no", that the crankshaft pulley is key-wayed, so it only fits on one way. He suggested that there might be something wrong with either my timing light or how I'm doing it. Don't want to make this a "me vs. the mechanic," but I think I'm doing it right. I can hook up my timing light to my BII and get the right timing.

After all that, I believe the problem lies in one of the following areas:
1) Operator error. I believe I'm doing it right, but there is a small chance that I'm not. What could I be doing wrong? I don't think there's a problem with the light itself, it works well on other applications.
2) Or something isn't put together right on or inside the engine. They say it can only go together one way. Anyone who's had one of these apart, is this true? Could there be a problem in how the crankshaft pulley was installed? What about something deeper in -- maybe on the engine rebuilder's part that the installer wouldn't ever see or mess with? timing chain? timing sprockets?

Because the engine is running, I believe that the true timing is 10* BTDC. I'm just not able to measure the actual timing. If anyone has anymore ideas, I'd appreciate hearing them.

 

[JDraper]

I've rebuilt many motors, and if the engine is running right, it's most likely put together properly inside. If the timing chain was installed wrong (i.e., the cam is out of synch with the crankshaft) it wouldn't run very well, or not at all. If you really want to check the timing, the best way to tell if everything is properly installed is to bring the #1 piston to TDC, pull the #1 spark plug, remove the cap from the distributor, and remove the valve cover over the proper cylinder bank. At TDC, the piston should be at the top of it's stroke, both the #1 intake and #1 exhaust valve should be closed, and the rotor should be pointed at the #1 electrode in the cap.

Is your timing mark on the pulley, or on the harmonic balancer? If it's on the pulley, it might be possible that the pulley was installed wrong, but I don't know if the pulley on your motor is keyed or not.

If the mark is on the harmonic balancer, it's possible that the outer ring of the balancer has slipped, but you would likely have some vibration out of the motor if that was the case.

It's also possible that the wrong pulley or balancer is installed on the engine. When it was rebuilt, they could have used the pulley or balancer from a different engine.

If everything checks out and the timing mark is still off, you can buy timing tape from Summit Racing, Jegs, etc that you put on your harmonic balancer to give you the proper marks.


One more dumb question. Are you sure you are using the right mark on the pulley?? Check the balancer too in case there is a mark on it too.

 

[AlaskanJack]

JDraper - I believe this was on his explorer so no distributor or rotor

My thoughts exactly on this but I don't know if the pulley has a keyway I guess I could go look on mine.

 

[MrShorty]

I went out and looked at the crankshaft pulley, and it looks like it might be two pieces. Someone (Chilton's, Haynes, or Mitchell) calls it a "pulley and damper" assembly, but I can't find anything about separating the two pieces.

 

[JDraper]

Usually when the pulley and damper are two separate pieces, there are 3 or 4 bolts (besides the center bolt that holds everything to the crankshaft) that hold the pulley to the damper. Most of the time you can remove the belt(s), pull the bolts out of the pulley, and it will either drop off, or it can be tapped off with a soft mallet.


If this is your 4.0 in your X, I've been looking at the manual for it, and, according to the Haynes manual (and my recollection from my old '92 Sport), there is a notch in the pulley that you time off of, which is probably the notch you are looking at. Also, from the pix in my book, the pulley and damper assembly is one piece.

 

[SteveVB]

Did you check to see if the balancer marks line up at TDC #1 cylinder on the compression stroke?

I would also check the timing from the #4 see if maybe the wrong cylinder was at TDC compression when the
balancer was installed. Meaning the rebuilder had the engine at TDC on #4 (the other front cylinder) when he installed and lined up the chain and balancer.

Your rebuilder is correct- the parts only go together one way, BUT they must be installed when the crankshaft is in the correct relative position for a specific cylinder number.

Cylinders 1 and 5 fire together so 5 should give you the timing reading for the 180deg off of number 1.

let us know what you find..

 

[AlaskanJack]

SteveB - His engine runs just fine if it were installed 180 degrees off the engine wouldn't run.

 

[MrShorty]

Think I've got it figured out

Been doing some further research on this, and I think I've figured out what's going on. The "crankshaft pulley" is indeed a multi-piece assembly. The inner portion that fits directly on the crankshaft and which has the "notches" that the CKP sensor uses to tell the position of the crank (There are 35 "ridges" spaced every 10°, the 36th one is missing). Around this is attached a rubber ring, which separates the inner portion from the "harmonic balancer/pulley" (this is where the belt rides). I talked to the rebuilder, and he said that on some engines (mostly Chevy engines, he didn't know if Ford's 4.0 OHV had this kind of set-up or not) with this kind of set-up, the pulley/balancer portion can slowly "rotate" around the crankshaft. For reference sake, I called a Ford dealer who had a new pulley assembly in stock and asked him to tell me what the relative positions of the TDC timing mark and the missing "ridge" were. They are supposed to be in the same relative position. On mine, they are 170° apart.
Anyway, I think what I've really learned from this is that, to properly check the timing on this engine, it could be important to do as SteveVB said, and that is to find TDC before checking the timing. I don't know if I could trust the timing marks on the pulley.

 

[Runnin'OnEmpty]

Mr Shorty, I think you found it. It seems like the balancer has slipped on it's center hub. I'll just bet that it'll run a lot smoother with a new balancer......

With these "lost spark" ignition systems, it dosen't matter whether it's timed on the compression or exhaust stroke; the cylinder fires at both positions.

 

[AlaskanJack]

Aha I knew it had to be the pulley.

 

[Tony H]

Distributor

Sounds like someone had the distributor out and put it back in when the #1 cylinder was in the exhaust stroke not the combustion stroke.

Distributor has to be romoved and rotated 180 degrees

 

[JDraper]

Re: Distributor

Originally posted by Tony H
Sounds like someone had the distributor out and put it back in when the #1 cylinder was in the exhaust stroke not the combustion stroke.

Distributor has to be romoved and rotated 180 degrees

See posts above. If it's in his Explorer, there is no distributor, so that pretty much leaves the harmonic balancer ring slipping...