Hey guys,

Here's the situation, we've got a 1984 with the 2.5 liter Iron Duke that just recently tore up it's fiber timing gear on the camshaft. So after pulling the camshaft and pressing a new one on, in addition to replacing the distributor cap/rotor, spark plug wires, and ignition coil...we can't get this thing timed right to turn over.

The dots on the camshaft gear and crankshaft gear are lined up and the rotor is pointing between the 1 and 3 spark plug posts when cylinder 1 is at top dead center (and the timing mark on the crank pulley is at 0).

Here's a video to show you guys what's going on: http://www.youtube.com/watch?v=4R8dFQmKJrU

As you can see we're getting some backfiring through the throttle body and some air out of the exhaust but it's not turning over. We've checked the plugs for spark and I can see it getting fuel, and we've got the ECM posts connected with a paper clip in order for it to hold the timing, but it's still dead in the water.

Thanks in advance for your advice and help!!!!

well there is this i have read many time where the things your soppost to line up to time it can be come off though time in other work find a way to time it with out marks on the car

Well we looked at the piston and made sure it was TDC when we put the distributor back in so I'm fairly certain it's on the money.

Distributor maybe bad too... and that why the cam gear strip. Distributor is cam drive.

By the sound, You have a dead battery.

------------------
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Charge up the battery and then as you crank the engine slowly turn the distributor a bit in either direction until it fires up.

Take out the #1 plug. Either put a compression gauge in the hole or your assistant's finger. Turn the crank clockwise until either the compression gauge starts moving or your assistant starts making a weird noise. Then continue forward till the mark on the crank pulley aligns with the 10deg before spot on the marker. Stop there. Do not turn the crank backwards to get to that spot.

Now look at the dist. It HAS to be aligned to point at the #1 tower. If you can rotate the distributor to get it so the rotor is pointing to #1 that's fine. (loosen the hold down bolt) If you can't get the distributor to rotate enough to point at the #1 plug you might have to take the hold down bolt out all the way, then lift the distributor. As you lift it note how far the rotor turns. Before putting the dist back in put the rotor pointing in a position so when all the way back in, the rotor is pointing towards where the #1 tower is supposed to be. When installing the distributor you most likely will have to rotate the crank to get the distributor to drop in all the way. Then again rotate the crank clockwise till you are on compression and then continue till you are at 10* before tdc on the compression stroke.

Just as a double check pull the rotor off the dist shaft now and make sure the rotor points the same way as the notch on the shaft.

Now with the crank either still at, or back at 10 deg before tdc on #1, do a minor turn on the distributor to align the prongs and points of the reluctor and stator below the rotor. Get the points of each to point exactly where the other is. Snug down the hold down bolt. Now re-check to make sure the rotor is pointing to the #1 tower. Double check the firing order of the distributor. It turns clock wise. The firing order is 1-3-4-2. Now put the spark plug back in, reassemble the distributor and start the engine.

You will have to put the timing exactly on with a light after this however this procedure WILL align the distributor close enough to start the engine.

rotor should be pointing more like between 1 and 2 towers when at #1 tdc.

Is your tach reading when cranking the engine over?

You mean between 1 and 3. Your still wrong however.

If your 10 deg before tdc for firing, that's only 5 deg on the distributor since it turns 1/2 speed. 5* past the the center of the plug tower for #1 should still be where the width of the rotor and the width of the tower are still together.

The crank needs to turn 180 degrees to get from firing #1 to where it fires #3 (The firing order is 1 - 3 - 4 - 2)

It doesn't make much sence to have the rotor between plug wire towers when you fire the spark.

[This message has been edited by phonedawgz (edited 12-14-2010).]

I'm getting a new battery manana..new plugs too, I'll check on the RPM then...thanx!

quote Originally posted by rlloz: I'm getting a new battery manana..new plugs too, I'll check on the RPM then...thanx!

Timing??

quote Originally posted by phonedawgz: You mean between 1 and 3. Your still wrong however. If your 10 deg before tdc for firing, that's only 5 deg on the distributor since it turns 1/2 speed. 5* past the the center of the plug tower for #1 should still be where the width of the rotor and the width of the tower are still together. The crank needs to turn 180 degrees to get from firing #1 to where it fires #3 (The firing order is 1 - 3 - 4 - 2) It doesn't make much sence to have the rotor between plug wire towers when you fire the spark.

Not even worth the argument, but I do have one thing to say...

It's Y O U- APOSTROPHE- R E whcih is a contraction for YOU ARE.

My guess it is getting the correct information is well worth it to the person who has been fighting to get his engine to s. To tell him the

quote rotor should be pointing more like between 1 and 2 towers when at #1 tdc.

means he will spend one more day fighting to get it to run.

This is my V6 dist with the engine at TDC on cylinder #1. Both the V6 and the Duke use the same base timing setting. (10* before tdc) So when you look at just the offset of the alignment of the points and prongs, and the alignment of the rotor to the #1 spark plug wire tower, they will be the same. If you look at the offset between the points and prongs, that is exactly the offset of the rotor and tower. As you notice the rotor's contact is much wider than the points of the reluctor. The width of the spark plug wire tower's contact is also wider than the prongs. So yes at TDC, part of the rotor's contact will still align with part of the tower's contact. Note these parts don't actually touch, they just align, and the spark jumps the gap between them.

Also note this is with the engine actually at TDC. Base timing is 10 deg (crank) before this. Turn the distributor's shaft back 5* (1/2 speed of the crank) and they align pretty much right on. Figure with the max timing the ECM put's into the timing and the contact is at the other extreme of still aligning with part of the tower.

So yes, if the rotor isn't fairly aligned with the #1 spark plug tower wire, at TDC, or even a better check would be to do it at 10* before tdc, you're going to have problems getting your engine to start.

Well, new battery...same problem!!.. I made sure the timing was set properly 10' before TDC w/ #1 tower. She backfires & doesn;t start!. I read where the rocker arms can be to tight (torques to 20#)..so I'll try loosening them slightly . Cylinder compression read 30 # consistently.My question to all is would the distributor malfunction and still be sending a spark to the plugs??
How do you check the electrical components ? If the distributor failed it might have caused the cam gear to shear?
My favorite present this year would be getting this baby to run again!!! MERRY CHRISTMAS!!!!!!!!!!!!

30#??!!

You have a MAJOR problem there.

Your valve lash is way too tight most likely

30# is WAY WAY off

Thanx for the quick reply!!!....I'll try loosening them and check the compression

If your engine is backfiring that means for sure that you ARE getting some gas into the engine and it means you ARE getting spark into the engine. So your distributor IS producing a spark. Maybe not at the right time. Maybe at the right time.

Fix whatever is causing the low low low compression and my guess is it will start.

quote Originally posted by phonedawgz: Yeah Haynes says 20 ft-lbs for the rocker arm torque on them. I have only taken out 2.5's so I don't have experience with that rocker arm setup directly. You also have to turn the crankshaft 180 degrees between setting the valves. Each cylinder should be tdc on it's compression stroke. You can figure out where #1's is by rotating the crank clockwise till you see first the exhaust open and close and then intake open and close and then continue till time timing mark says tdc. After setting #1, then rotate the engine 180 degrees and do #3. Then 180 more and do #4. Then 180 more and do #2.

You don't do this with the Duke, you just tighten the rocker arm bolts to the specified torque (I can't remember the torque value off the top of my head). You just tighten the bolts regardless of camshaft position. I've done it a bunch of times and I usually don't even bother with a torque wrench, I use a 3/8 ratchet, don't use a breaker bar with a pipe on it and you will be fine. There is no need to find TDC like you do on a SBC or V6.

Haynes - Chapter 2 Part A (Four cylinder engine)

Section 7 Hydraulic Lifters

Installation

Step 15 - CAUTION: Make sure that each pair of lifters is on the base circle of the camshaft; that is, with both valves closed, before tightening the rocker arm bolts.

20 Ft-lbs

[This message has been edited by phonedawgz (edited 12-22-2010).]

These Duke "net lash" rocker systems don't require following a sequence to get the proper lash. No matter where you're at on the cam, lash is set at a fixed value, which is controlled by the height of the shoulder bolt.

If you're only getting 30 psi, you need to do a leak-down test with the pushrods completely removed from the valvetrain. If you're still seeing high leak-down rates, then there's more problems than you at first counted on.

So looking back at the thread - when you re-installed the camshaft into the block - did you align the marks on the camshaft gear and the crankshaft gear? There are marks on the gears that MUST be aligned for the engine to operate. If you didn't notice them or didn't align them, that is indeed your problem.

Also I woud not deviate from the factory recommended procedure for adjusting the valves.

There's a key on the camshaft so I don't think that's an issue...my compression is an issue I hope is fixed w/valve adjustment. We marked all the pushrods in order and installed as such...same as the lifters. The camshaft had normal wear w/ no burs or devits on the lobs. I'm gonna retest the compression and see what happens.

Put a drop or 2 of oil in the spark plug hole before testing the compression.

I would duble chech the cam -crank timing if the car was running good when the cam gear failed, it is verry possible that the cam gear is out of time. remove the timing cover and check to see that the marks line up now check that the dist rotor points to the #1firing position. the reasion I suggest this is that engine compression is formed when the pistion compresses a closed cylinder if the valves are not closed at top dead center compression will be low.

quote Originally posted by silverbullet910: I would duble chech the cam -crank timing if the car was running good when the cam gear failed, it is verry possible that the cam gear is out of time. remove the timing cover and check to see that the marks line up now check that the dist rotor points to the #1firing position. the reasion I suggest this is that engine compression is formed when the pistion compresses a closed cylinder if the valves are not closed at top dead center compression will be low.

Well when he removed and re-pressed on the timing gear, the cam was out of the engine. To remove the cam he had to remove the dist. So while yes the dist has to be pointed in the right direction for the car to run, it won't be any indication of if the cam/crank are aligned correctly.

If after adjustment and/or oiling the compression isn't there the next thing to look at will be to open it back up and re-check the cam/crank timing. Again, you can get a guesstimation of it by looking at the valve events with the valve cover off.

A little update on our situation...

After doing another compression test after adding oil to the cylinders we got 80 PSI on all 4, which is a big jump from the 60-40-35-40 we were getting before. So I think we've got some worn piston rings in the mix?

In addition we loosened up the rocker arm bolts to 15 in. lbs. to see if we had the valve springs compressed too much and that didn't seem to resolve the issues. Just to be sure the valves weren't the issue we loosened up the rocket arm bolts completely while we were testing the compression and that didn't help to improve the compression either. We're still getting backfiring and gas out of the throttle body and low compression.


We did find another thread where a guy rebuilt his 2.5 and had too thin of a head gasket and observed the same issues we have, and after going to a thicker gasket he got it to fire right up.

Is it time for us to start hunting Craigslist for a new Fiero or what?! Haha!

[This message has been edited by rlloz (edited 12-27-2010).]

A leakdown test is a better indication of the quality of the ring seal.

Well since you have the compression where it should start, now I think you have just an ignition timing issue. Turn the engine forward by the crankshaft pulley bolt clockwise till #1 is on compression. Then continue turning clockwise till you line up the 10 deg before tdc and then stop. If you do overshoot, turn back at least 1/4 turn and then forward again. Now with #1 on compression, and stopped at 10 deg before TDC, open the dist cap and look at the points and prongs of the distributor - located under the rotor. Loosen the hold down biolt and line up the prongs and points as perfectly as possible. Snug down the hold down bolt. Now look at the rotor. It should be pointing pretty much right on to a spark plug tower. If it's beween towers, pull the rotor off and make sure the rotor is on the notch in the distributor shaft.

So now the engine is at 10 deg before TDC, the distributor points and prongs are lined up, the dist is snugged down. Now take note where the distributor rotor is pointing. That IS your #1 spark plug tower. Doesn't matter what the pictures in the book say.

Then following around the distributor fill in the other 3 wires CLOCKWISE. The order is 1 - 3 - 4 - 2. Clockwise. So make sure the rotor is in, make sure it's still pointing at the now #1 tower.

Put back in any spark plugs you have out, make sure you don't still have a wrench on the crankshaft, and go and start the engine. If the engine fails to start, you need to double check your alignment of the cam and crank. If the engine is still backfiring through the intake you need to re-align the cam and crank.


Points and prongs lined up (yeah I know it's a 6)



Note, if you look at any dist, either the 6 or the 4, when the points and prongs align, the rotor also points at a spark plug tower.

I'm not sure if the 4 is the same as the 6, but when the points align you will note the notch in the dist shaft is right in the middle of the prongs. This is because the spark plug towers are aligned to be in the middle of the prongs of the distributor.

[This message has been edited by phonedawgz (edited 12-27-2010).]

As alreadymentioned, the stars must be aligned for things to go right.
If you are 100% sure the dots are aligned on the crank and cam gears, make sure the balancer has not slipped, as in the outer ring not still attached to the inner due to the rubber going south.
Pull number one plug. Plug closest to front of engine.
Turn motor over BY HAND, repeat BY HAND while you have a finger over the hole for number one spark plug.
When you hear/feel the air pushing by your finger, you are approching the firing stroke for that cylinder. Looking at the timing mark on the balancer align it to the TDC mark.
Then check to see if the rotor in the distributor is pointing at the tower for number one cylinder. If not, something is wrong mechanically.
If it is, something is wrong electrically.

quote Originally posted by phonedawgz: Haynes - Chapter 2 Part A (Four cylinder engine) Section 7 Hydraulic Lifters Installation Step 15 - CAUTION: Make sure that each pair of lifters is on the base circle of the camshaft; that is, with both valves closed, before tightening the rocker arm bolts. 20 Ft-lbs

Chilton says 24 ft lbs. Now what do we do?...........

I do agree with TONY_C and KurtAKX, position of the cam will not matter in this case.


Kevin

idk why the Service Manual says to do it with cam on the base of the lobe. Perhaps they feel the extra pressure will affect the torque settings. idk. I hear ya when your talking about tightening down to a collared stud. I'd prob do it the manual way just to make sure I wasn't screwing up something however.

When giving advice I tend to caution even more and go with the manual.

[This message has been edited by phonedawgz (edited 12-27-2010).]