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Unread 01-30-2008, 11:50 AM   #31
laybackman
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Quote:
Originally Posted by Alfons
Laybackman may have a point in that the ECM is trying to compensate as much as it can, but I don't think you want to move the distributor further into the advanced area. With each tooth of the distributor representing approximately 28 degrees (there are 13 teeth on the distributor, and 360 / 13 = 27.69), so if it was moved further in the advanced direction, it would be trying to fire an additional 28 degrees before it's firing now (it's already 12 degrees BTDC, so that would make it 40 degrees BTDC) - I don't think it would start. You may need to "loose some" advance, (go the other way by one tooth) but if you could take a picture or two of your distributor at TDC showing the rotor position and the #1 cylinder mark on the distributor case, that would be helpful. The other points made by laybackman are also good - the whole throttle body could use a cleaning - there's a gallery from the IAC cavity that goes farther down into the throttle body & can get clogged.

BTW, do you know for sure that #1 piston is at TDC or are you just going by the timing mark?
Actually your calculations should be 360 degrees of rotation divided by the number of cylinders you have (6) that's approximately the 30 degrees he is off by. Agreed?

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Unread 01-30-2008, 11:57 AM   #32
veritas4156
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Here are the pics of the rotor at two different positions. At the first position it runs(this is what its set at on the video). The second picture it backfires out the intake but will not run. The video should give you a good idea of what it sounds like.

http://i215.photobucket.com/albums/c...6/IMAG0007.jpg
http://i215.photobucket.com/albums/c...6/IMAG0008.jpg
And the video should be on youtube shortly. I have to run to class but if you search for "YJ running rough" you should be able to find it soon. I'll edit in a link later.
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Unread 01-30-2008, 12:10 PM   #33
laybackman
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Quote:
Originally Posted by veritas4156
Here are the pics of the rotor at two different positions. At the first position it runs(this is what its set at on the video). The second picture it backfires out the intake but will not run. The video should give you a good idea of what it sounds like.

http://i215.photobucket.com/albums/c...6/IMAG0007.jpg
http://i215.photobucket.com/albums/c...6/IMAG0008.jpg
And the video should be on youtube shortly. I have to run to class but if you search for "YJ running rough" you should be able to find it soon. I'll edit in a link later.
Picture #1:If you put your dist cap on the dist where would the tower for #1 spoark plug wire be?
I suspect that it would be just in front of the rotor in picture #1. Now with the dist in and snugged down a bit and the cap back on, with the engine running do you have a bit of movement CW and or CCW to correct your timing some?
Picture #2 If it is backfiring through the TB then your firing before TDC.

I would also get the ECM dumped like I suggested with the dist in pic #1position try to move it some to dial in the timing using your timing light.
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Unread 01-30-2008, 12:14 PM   #34
Alfons
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Quote:
Originally Posted by laybackman
Actually your calculations should be 360 degrees of rotation divided by the number of cylinders you have (6) that's approximately the 30 degrees he is off by. Agreed?
Sorry laybackman, I can't agree with that. If we were talking about the cap, then I would agree that the number of cylinders is relevant and that the angular distance between any two distributor cap posts would be 360/60=60 degrees. The gear on the distributor has 13 teeth and to turn it (either way) from one valley to the next gives you an angular distance of 360/13=27.69 degrees (approximately) - this gives you the smallest adjustment that you can make on setting up a distributor on a 4.0 I6. The following is only an example to express gear configuration - You could use the same distributor gearing geometry on the 2.5 if the cam-to-distributor gear was the same as used on the I6 and you'd get one rotation of the distributor for every two rotations of the crank - the number of cylinders don't matter at the cam-to-distributor interface level.
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Unread 01-30-2008, 12:23 PM   #35
laybackman
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Quote:
Originally Posted by Alfons
Sorry laybackman, I can't agree with that. If we were talking about the cap, then I would agree that the number of cylinders is relevant and that the angular distance between any two distributor cap posts would be 360/60=60 degrees. The gear on the distributor has 13 teeth and to turn it (either way) from one valley to the next gives you an angular distance of 360/13=27.69 degrees (approximately) - this gives you the smallest adjustment that you can make on setting up a distributor on a 4.0 I6. The following is only an example to express gear configuration - You could use the same distributor gearing geometry on the 2.5 if the cam-to-distributor gear was the same as used on the I6 and you'd get one rotation of the distributor for every two rotations of the crank - the number of cylinders don't matter at the cam-to-distributor interface level.
Alfons you are right! Alfonds is right! My calc gives you 60 dgrees of sweep so you can determine the position of the plug towers by my calculation. (That would get you in the right quadrant of the dist cap.) If you are not in that area you are way off. I think he has it right in the 1st picture but needs to move his dist one tooth to get the ~30 degrees he needs to get TDC
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Unread 01-30-2008, 12:37 PM   #36
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Quote:
Originally Posted by laybackman
Alfons you are right! Alfonds is right! My calc gives you 60 dgrees of sweep so you can determine the position of the plug towers by my calculation. (That would get you in the right quadrant of the dist cap.) If you are not in that area you are way off. I think he has it right in the 1st picture but needs to move his dist one tooth to get the ~30 degrees he needs to get TDC
I think you're right, I think he needs to move it clockwise one more tooth as you had originally mentioned.

Veritas, have a look at this picture of your's that I marked up and tell me if my marking is correct.

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Unread 01-30-2008, 12:57 PM   #37
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Here's your pic again, I've marked the area where I believe # 1 post should be on your distributor since that's where it is on mine.

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Unread 01-30-2008, 02:16 PM   #38
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Here is the link to the video so you can here how my jeep is running:
http://youtube.com/watch?v=IDNONR8fqoc

Alfons, you are right in the location of the number 1 post on my distributor. I believe it is the OE distributor, I haven't changed it but I know it was changed by the PO with one out of a junkyard. I got a bit confused with the green line pointing further along clockwise on the distributor. Is this location where your distributor post is? I work at an auto parts store so I can go in to the store with my cap and see if different brands have the post in different locations for some reason. If you really think I have a different distributor I can try hitting up the junkyard. I'm going down there this weekend to get parts for my friend's integra.

I also checked the plugs again and between getting it running and trying to get it running right, all of the plugs seem to be fouled out. I'm going to pick up some cheap plugs at the store today to use until I get it running right.

Let me know, I need to get it running ASAP(even though I'm doing all this outside in snowy 10-15 degree weather) because someone is buying my other car on Friday! I really appreciate the help
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Unread 01-30-2008, 03:08 PM   #39
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Here's a picture of my distributor with the cap on. You'll notice where the mark is on the distributor case and where #1 post is on my distributor - the tail of the rotor on mine at TDC is just on the mark. If you look at your distributor & mine, you'll notice that the cap hold-down screws are in the same place, the sensor "pig tail" is in the same place, etc., but you say that your #1 post is one up from mine - I don't understand that. I've set my distributor up to look like yours when I'm not watching what I'm doing & it'll start, but will run bad - as you accelerate, it will loose power and start to miss. Moving it to where I have it now gives me smoooooth running.

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Unread 01-30-2008, 04:37 PM   #40
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Hmm I really wanna go look now but its like 20 degrees out and dark and the wind is blowing at like 30-45 mph... Oh well I'll be cold. Be back in 20 with pics and possible results.
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Unread 01-30-2008, 06:43 PM   #41
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Alrighty so I felt like a big idiot when I went out to my car to look at the distributor to try and figure things out because it turns out that the wires were all in the correct order, but they were one post counterclockwise each. I then moved all the wires and reset the distributor and it fired right up, although it is running quite rough still Now I'm thinking it could be because the plugs are so fouled its just missing, but then again it sounds EXACTLY like it did before, probably because the positions of the posts dont really matter all that much, its the same distance between them and they were in the correct order. I'm going to replace the plugs in the morning, reclean the throttle body(did some backfiring again so I probably have some nice crud built up in there) and fire it up and see how it runs. Hopefully its just the plugs.
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Unread 01-30-2008, 06:52 PM   #42
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Quote:
Originally Posted by veritas4156
Alrighty so I felt like a big idiot when I went out to my car to look at the distributor to try and figure things out because it turns out that the wires were all in the correct order, but they were one post counterclockwise each. I then moved all the wires and reset the distributor and it fired right up, although it is running quite rough still Now I'm thinking it could be because the plugs are so fouled its just missing, but then again it sounds EXACTLY like it did before, probably because the positions of the posts dont really matter all that much, its the same distance between them and they were in the correct order. I'm going to replace the plugs in the morning, reclean the throttle body(did some backfiring again so I probably have some nice crud built up in there) and fire it up and see how it runs. Hopefully its just the plugs.
As far as the right firing order but wrong tower mistake I have done that more times than I can remember!
I would pull the + battery cable and then ground it out for 30 seconds or so to dump the ECM'S learned memory. Reconnect the + battery cable. When you start up your rig it will now be running on the factory presets. Take it for a spin so it can start to gather new input values. Ride it for at least until it gerts inyto closed loop mode (engine temp full warm). If you still have a rough idle I would pull the IAC in the TB and c;lean it wioth carb cleaned and a piece of fine steel woll. Clean out the bore in the TB also. BE CAREFUL with the IAC plunger. do no pull it out. IF you do go buy another one. Let us know how you make out, OK?
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Unread 01-30-2008, 07:07 PM   #43
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According to the book the rotor should be at the 5 O'Clock position when the trailing edge of the rotor blade is lined up with #1 post on dist cap
Put your cap on and mark #1 post on dist body and set the dist according to the mark.
I does look like it appears you are off by a tooth, gently lift it up and turn it just a bit and you should be good.
Quote:
Originally Posted by veritas4156
Here are the pics of the rotor at two different positions. At the first position it runs(this is what its set at on the video). The second picture it backfires out the intake but will not run. The video should give you a good idea of what it sounds like.

http://i215.photobucket.com/albums/c...6/IMAG0007.jpg
http://i215.photobucket.com/albums/c...6/IMAG0008.jpg
And the video should be on youtube shortly. I have to run to class but if you search for "YJ running rough" you should be able to find it soon. I'll edit in a link later.

Last edited by pat8942; 01-30-2008 at 07:17 PM..
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Unread 01-30-2008, 07:40 PM   #44
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Good luck, hope things work out. It's doubly frustrating when things don't quite work & it's so cold you can't think straight enough to fix it. I'll tune in tomorrow sometime and see if I can pass on any more bs... er, experience

Out of curiosity, did it ever run right?
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Unread 01-30-2008, 08:48 PM   #45
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Well heres the story behind it; I went to buy another YJ, and the guy sold it the day after I told him not to because I would bring him cash the next day. He felt bad so he called me and told me his friend had this one but it wasn't running. By the time I called him to help him troubleshoot it to see if he could get it running so I could hear it run before I bought it he had already done the plugs wires cap rotor and redone the base and distributor timing. I told him to replace the crank sensor and it started to fire a tiny bit. After all that I couldn't figure out what was wrong so I bought a rust free 88 YJ 4.0L 5spd for $1600. When I got it I replaced a few sensors and it still wouldn't turn over so I started messing with the distributor timing. This got it to fire a little more so I realized it was a timing issue. I then redid the base timing(which was off by about a centimeter) and am now working on the distributor timing and whatever else may be causing my misery.
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