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Old 10-29-2020, 06:30 PM   #1
ChadK
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Default Flywheel timing still off?

So some backstory, I manual swapped my 91 240 and forgot to mark where the blank spot on the flex plate is, I'm sure you can guess the rest.

Didn't realize until after, so I pulled the trans again, put the motor to TDC using the crank pully and dizzy now here's where the real problem starts. The blank spot didn't hit the starter hole, it was either above or below (inline with the starter bolts, nothing crazy). I chose the bottom bolt but the car still seems like its misfiring at low idle.

It idles okay, runs fine when on the throttle, but low rpm cruising is rough. Did I miss TDC? am I off a bolt whole? probably going to pull the trans again tomorrow night and look at it again but any ideas would be much appreciated
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Old 10-29-2020, 06:48 PM   #2
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If the engine started, your flywheel timing is correct. Look for other problems
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Old 10-29-2020, 07:50 PM   #3
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Hi
stick some thing down the plug hole to find TDC
the pulley can move on its rubber
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Old 10-29-2020, 08:00 PM   #4
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+1 on the two posts above.

The motor just won't run at all if you're a whole bolt off.

And verify that TDC isn't quite right as suggested - if the outer shell on the front pulley is moving you'll probably want to replace it at some point, it will just get looser and might eventually come apart.
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Old 10-29-2020, 08:05 PM   #5
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Quote:
Originally Posted by hessam69 View Post
If the engine started, your flywheel timing is correct. Look for other problems
That is not correct. The flywheel can be at least one bolt off which is 45° of ignition timing and the engine will still start and run pretty well. I just went through this with a customer back east. Someone replace his rear main seal and put the fly wheel on wrong. It went through two shops before they got it figured out when they called me about how to figure out whether or not the flex plate was on correct. In his case it was two bolts off according to the shop. The electronic ignition can compensate for an incredible amount of timing it appears. The person that did the rear main seal had removed the rubber plug from the distributor slot and turn the distributor attempting to tame the engine. That’s probably why they got away with so much advance or retard. I didn’t see the car personally.

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Old 10-29-2020, 08:40 PM   #6
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+1 on the two posts above.

The motor just won't run at all if you're a whole bolt off.

And verify that TDC isn't quite right as suggested - if the outer shell on the front pulley is moving you'll probably want to replace it at some point, it will just get looser and might eventually come apart.
Had a customer years back that had his come apart. Totaled the very nice 740. Hood battery wire harness water pump radiator trans cooler lines engine covers inner fenders and more that I can’t remember.
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Old 10-29-2020, 10:14 PM   #7
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Yeah I've read about that pulley moving. I figured that because the dizzy and it were lined up its probably pretty close, I'll check it though

so my next question is, what could cause the issue? I have a MAF that I could swap. The idle air controller maybe as it idles real low? I thought maybe its a fuel issue at first. It ran fine before the swap. Timing belt slipped somehow?

I did take it to a shop initially and they were the ones that suggested the flywheel may be on incorrectly. I've also read about people installing it wrong and getting their car started only to have it run like trash. I'd prefer to diagnose somethings before pulling the trans again if that's possible.
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Old 10-29-2020, 10:22 PM   #8
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You don’t need to pull the transmission to check for correct fly wheel placement. Just pull the starter and put the engine to top dead center on number one cylinder and look through the hole for the starter for the double space window that triggers the crank position sensor. That’s what the shop did for my customer back east. They had to turn the crankshaft almost 90° further in order to get that wide gap to appear in the starter hole.
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Old 10-30-2020, 05:10 AM   #9
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Verify TDC with a straw or chopstick through spark plug hole #1, then check to see the marks on the damper line up with zero.

Then turn the crank bolt exactly 90° clockwise (90° ATDC). Use chalk if you're not sure. Then, just look for the index in the EZK ring. Beats pulling the starter.



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Old 10-30-2020, 09:01 AM   #10
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Just check it at idle with a timing light.
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Old 10-30-2020, 10:13 AM   #11
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Just check it at idle with a timing light.
As Roy mentioned above, EZK is quite forgiving about 45° mistakes at the CPS, based on experience helping others solve this. Like the OP sees, it idles, but falls on its face driving. However, I don't remember if anyone put a light on the damper mark with it idling and one bolt hole off. I imagine it might look good.
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Old 10-30-2020, 01:59 PM   #12
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Originally Posted by cleanflametrap View Post
Verify TDC with a straw or chopstick through spark plug hole #1, then check to see the marks on the damper line up with zero.

Then turn the crank bolt exactly 90° clockwise (90° ATDC). Use chalk if you're not sure. Then, just look for the index in the EZK ring. Beats pulling the starter.



That's a much easier method if the person investigating can keep track of what they are doing.
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Old 10-30-2020, 02:06 PM   #13
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I'm not sure if the flywheels have a mark like the flexplates, but all the 2.4 flexplates I've seen have an arrow on them. With the engine at TDC that arrow points at the sensor. With the inspection plate off you'd be able to find the arrow, then mark the tone ring, spin the engine to TDC and make sure the mark lines up with the sensor.

Just another method, same as CFT mentioned.
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Old 10-30-2020, 02:09 PM   #14
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Yes, however, the idiots put the arrow on the wrong side of the flex plate. It faces the block. IOW, when installing the flex plate you can't see where the arrow is pointing. You have to transfer the mark to the side of the flex plate facing you.
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Old 10-30-2020, 09:25 PM   #15
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Yeah, well, there is that. lol
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Old 10-31-2020, 12:22 AM   #16
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Quote:
Originally Posted by 2manyturbos View Post
That is not correct. The flywheel can be at least one bolt off which is 45° of ignition timing and the engine will still start and run pretty well. I just went through this with a customer back east. Someone replace his rear main seal and put the fly wheel on wrong. It went through two shops before they got it figured out when they called me about how to figure out whether or not the flex plate was on correct. In his case it was two bolts off according to the shop. The electronic ignition can compensate for an incredible amount of timing it appears. The person that did the rear main seal had removed the rubber plug from the distributor slot and turn the distributor attempting to tame the engine. That’s probably why they got away with so much advance or retard. I didn’t see the car personally.
Yes saw this on an LH 2.4 240, everybody swore it needed new plug wires, ..after verifying TDC, etc., it could not be timed. Later we discovered the flywheel was pulled off when the clutch was replaced, and the shop re-installed it incorrectly(). The car still ran, but very poorly.

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Old 11-01-2020, 03:19 AM   #17
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TIP: do your best to pull up the slack on the "loose side". I have used those black metal paperclips to hold the belt to the sprocket, then tension it up


Never trust the the crank pulley mark. Use the sprocket/washer notch. Pull the upper timing cover and look down in there. It is rough to get the upper timing cover back in place with the water pump pulley installed. Chop the cover if you gotta.


+1 for Art's idea of confirming the gap in the windows without pulling the starter.

A cool way to find number 1 TDC is to put a tissue in the spark plug hole. When it blows out, you are on the compression stroke.
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Old 11-10-2020, 10:55 AM   #18
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A cool way to find number 1 TDC is to put a tissue in the spark plug hole. When it blows out, you are on the compression stroke.
Crank & Flywheel/Flexplate have a 1:1 relationship, where Crank/Cam have a 2:1 relationship in regards to TDC for compression stroke.

So, finding Number's 1 cylinder at its top's position is all that is required for installing a flexplate/flywheel using a CPS
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Old 11-11-2020, 04:15 AM   #19
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Originally Posted by ChadK View Post
So some backstory, I manual swapped my 91 240 and forgot to mark where the blank spot on the flex plate is, I'm sure you can guess the rest.

Didn't realize until after, so I pulled the trans again, put the motor to TDC using the crank pully and dizzy now here's where the real problem starts. The blank spot didn't hit the starter hole, it was either above or below (inline with the starter bolts, nothing crazy). I chose the bottom bolt but the car still seems like its misfiring at low idle.

It idles okay, runs fine when on the throttle, but low rpm cruising is rough. Did I miss TDC? am I off a bolt whole? probably going to pull the trans again tomorrow night and look at it again but any ideas would be much appreciated
Funny enough I just did an m47 swap and didn't see the info about aligning the flywheel so I just bolted it up. Test drove it tonight, and it's popping like crazy when I let off the gas, but otherwise starts and drives without much issue. I'm assuming my flywheel is also off by a bolt. Wondering if most of the issue can be timed out without pulling everything apart again; that was a nightmare to do.
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Old 11-11-2020, 07:20 PM   #20
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The "tissue" method is for finding a compression stroke for doing a leak down test. Like on a V8 where it's not as easy to figure out as a 4 cyl.
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Old 11-12-2020, 02:17 AM   #21
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Originally Posted by StreetForged View Post
Funny enough I just did an m47 swap and didn't see the info about aligning the flywheel so I just bolted it up. Test drove it tonight, and it's popping like crazy when I let off the gas, but otherwise starts and drives without much issue. I'm assuming my flywheel is also off by a bolt. Wondering if most of the issue can be timed out without pulling everything apart again; that was a nightmare to do.
just convert it to 2.2

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