timing problem or miss match


ok....now im confused. when the distributor is installed as per directions then I have no spark....if its set in 1 tooth off it sputters...so to my understanding, if correct, then things are to far out of sink to work properly or there might be a short somewhere?
 
It dosen't sound like you have a short in your wiring harness but it's always good to be sure. I don't think this is the issue though . It looks as though we'll have to apply some Kentucky windage to the timing to get this engine to fire. Huh ? When the #1 piston reaches TDC , it will be somewhere BTDC and not necessary on O degrees. Tune up books do not give us a measurement of BEFORE top dead center because the PCM sets and adjusts ignition timing automatically. Tha leaves us in the dark . The #1 piston wil reach TDC a specified degrees before O degrees that we're trying set on the balancer scale . The piston will continue to stay in TDC while the crank is rotated a continued amount of degrees possibly ATDC or something until the piston actually starts to travel back down. Throw in some more slack caused by wear and tear of timing chain and gears to make more guess work. It it up,to,is to find that sweet spot. Swell. Marking a distributor on an engine before removal,of distributor would help upon reinstalation but that's not helping right now and wouldn't with a new distributor anyway or on a disturbed engine if it's spun with the distributor out. Either we would have to know what the timing mark is before top dead center when ignition actual begins to occur if able to find somewhere or would have to shine a timing light on a running 4.0 liter engine just to obtain a reference base line starting point. The act of following the book on distributor installation isn't helping as you well know. The PCM know where it wants the distributor set in terms of rotor pointing . Yes , it can only go in one way as you know in terms of oil pump shaft alignment , bracket to block mounting screw and rotor pointing to #1 cap terminal taking in to consideration leading edge , trailing edge or dead on of rotor contact tip to cap tower contact . But that's all fine , where does that leave us with crankshaft degrees ? That's why we're trying to go a tooth forward or back ( advanced or retard) . It would sure help,to get a timing gun on a running 4.0 to get a baseline. That would get on the map. I know this has got to have you misusing the vernacular . I still remember getting this kids 3.8 liter Buick engine to run when he yanked the distributor and didn't mark it before hand on a timing job once. What a day that was . I finally got it to fire. But we don't have the luxury of a new chain and gears. We got some slack . Swell. No , I don't want you to tear it down and install a timing chain set of it ran good before and didn't need one . We just got to find that sweet spot. This won't apply here beacause the 2.5 and 4.0 dwell cannot be manually adjusted as we well know but to help understand , I will explain and old trick to,fire up newly rebuilt engines quick to avoid excess cranking and dry cylinders due to little to no oil pressure at cranking while repeatedly trying to start . The distributor is installed TDC and the crank is rolled back to the BTDC mark and distributor is turned to meet the rotor with the cap.tower where it's roughly in adjustment . Although it cannot be done here with the 4.0 , the same idea at finding the before top dead center will find joy and the engine starting. Since this engine ran before , there shouldn't be any issues with anything like a problem flywheel and crank cannot find the windows to find ignition timing per cylinder. Just wanted to give some idea when things get tough and you start scratching your head thinking what to do , what to do. I know it has been a long , tough fight already that has folks ready to quit but this is why there no fire ( ignition ) and no joy ( elation). Just to complicate things , I hope that jeep dosen't have a factory security system that kills the ignition after battery disconnect or repeated no starts ? Didn't want to make matters worse saying that bit forewarned is forearmed . At least if we got to deal with that we' ll know that needs to be disarmed somehow. Just thinking back to that Buick when I thought I wasn't going to get it ( but knew it can be done ) and finally did and what it took ( repeated distributor stabbing ) to get it to fire has me believing that's what is needed here. The fact that dwell cannot help to get it to fire may actually be good as you'll only need to find the right crank rotation in degrees BTDC simplifying it , however a lot of reaching the crank balancer bolt with a 1/2" drive ratchet hopefully not a bunch of times . I still believe this is doable , just somebody wants us to work for it. Hope this extra long post gives some thought and some hope. I know if it ran before , it'll run for ya again.
 
If I don't figure this out soon I head a 360 will drop right in haha. Don't don't want to but might be the way do go of this thing don't run soon
 

here is a thought. can I cut off the plug for The 4 wire distributor and put the 3 wire a plug on itand see if that works. just need to know which of the 4 wires I don't need
 
I don't know if you mean a dodge 360 but assuming you mean an AMC 360 , it's an appealing idea . Just hate to see you have to bail out on all that work thus far. As far as the CMP mod , I don't think that will work . There should be one ground , one reference ( 5 volt or less ) and the two remaining will be signal feedback . On GM vehicles the cam sensors splice with the crank sensor. Really it is best if you can obtain a three wire CMP if can be done on the cheap like from the junkyard. Don't know if a mod will work .
 
OK I got a 3 wire with plastic cover and stuffed it in and still not much has changed. So I decided to put the timing light on coil wire. And found is sparking away but nothing is getting out except on cylinder 3. getting more confused as I go
 

It seems that there is slack in the timing chain . It may not be significant enough to cause performance issues but seems to be reaking havoc on your distributor placement . This is not news to you. My question is , how crankshaft movement in degrees are you getting before the rotor moves ? This is obviously affecting CMP synchronization and throwing off the #1 position firing order that is off from the Ckp position on the flywheel window marks. The PCM cannot maintain correct timing to fire the ignition or fuel injection firing order. It sounds like the PCM is seeing the CMP position on #3 when it is supposed to fire on #1. That's quite a few degrees off considering the firing order is 1-5-3-6-2-4. Starting to sound like its 180 degrees off ? I wouldn't think you've got the #1 piston on the wrong stroke but now wondering is there THAT much slack in the chain that the crank rotates and the cam lags that many degrees before it catches. Following that , it seems you've got quite a lot of work to get the cam to agree with the crank just so both shafts are in time. If the cam is not in time with the crank , the distributor gear on the cam will never be in the right position no matter how perfect the crank TDC mark is on the ZERO scale. That seems to be the whole problem with getting the distributor planted right when you stab it in each time your trying to get it in sync. I realize you well understand how to get it set up and I respect that but the slack in timing is just working against you . I know the engine ran before but somehow that sweet spot was lost and the distributor is not finding its original placement . Even though the chain and gears have wear , the distributor was in the correct position and the PCM would make corrections to advance/retard timing to compensate. This is the tough part. A person would literally have to keep placing the distributor in the correct position and maintain that placement while trying to advance or retard the harmonic balancer one or two degrees until the correct position is found since the chain slack will,take up,tension while cranking . This is of course trusting that the balancer has not walked due to the rubber ring let go from the inner hub to the outer ring. If so , it's virtually impossible to know if the engine is on TDC from the scale reading. You would literally have to look at the rotor movement when turning the balancer back and forth just to figure out how much rotation there is in degrees . What a handful. With the patience of a saint , it can be done but it's really time consuming. A timing chain may be in order of you've got that much slack . I'm really thinking that's what is preventing you from correct distributor placement and starting the engine. You simply cannot compensate for dwell by attempting to turn the distributor to find the correct point since this distributor isn't designed for dwell adjustment but must be set in correctly the same way every time. It is the crank that must be in total agreement with the cam to start the engine. I think you see my point and know what I mean since you've had your hands on this engine many times so far. I don't like. Asking you this but if you are will I got to pull the balancer and cover to align the timing marks , the cam gear will certainly be in the right place . You can see just how much slack the chain has on both sides when the chain is tight on one side and slack on the other in a natural tension enviriorment of its correct rotation . More than 1/2" or so constitutes a chain and gear swap. Hate to make you tear it down but if you can save yourself the time in disassembly and try the method I mentioned earlier by finding how much crank movement you've got back and forth before the rotor turns either way , you may find the right place the cam should be to sink the distributor . I would start in the middle of the total degrees of crank rotation back and forth and set the distributor the right way and go from there. I realize you would be guessing if the dots on the gears are aligned but trying to,save you time. I also,realize you would have to set the crank to #1 compression every time you'll need to change degrees if needed . Hmmmm ..... What is the lesser of two evils , this method or swapping a chain and sprockets ? Sorry to be asking a lot of you these days but you went through a lot already , would like to see you get the big payoff.
 
Joshua Faas said:
The coil sparks multiple times per revolution just seems to not be speaking when it should
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I believe the distributor will have to be set in place as it should but the crankshaft will have to be the correct degrees @ TDC . The trouble is , finding the right crankshaft position that ages with the distributor position. Can we trust the harmonic balancer , has the outer ring slipped and not in correct position with center hub ? That seems to be why the distributor cannot be set in the block right. Even though the oil pump shaft is lined up right and distributor drops down and bracket bolts up right , is the crankshaft really at the correct degrees regardless what the balancer mark is reading in the scale. Between the possible balancer slippage and possible timing chain and gears having too much slack , this causes incorrect valve timing and incorrect crankshaft position . These items will have to be checked. Surely a new balancer and timing chain set will correct this but you'll want to find out how much crank rotation you have before the rotor moves and confirm balancer mark is right . The only true way to confirm balancer is off or not would be to align the cam and crank gears using the dots. Then with the balancer on , you'll know if the TDC marks , scale and balancer notch are right . At least you'll be able to install the distributor right and fire up the engine. If it starts , you'll know what parts you need. If the engine has high mileage as it may , the timing chain and gears may have excessive slack. Trying this will cost muscle , time but no money to get it started . Only money spent is what's bad . Timing chain set good investment , the balancer should be changed if bad at chain set installation but can be done later if really need to . Your main concern is to find true TDC and the dots on upper and lower gear will get engine in time and will get distributor in right position in relation to camshaft so rotor will be at right cap tower when it should . If chain is really bad with too much slack , it really should be changed with new gears to get the engine started . With dots aligned , see if balancer mark aligns with TDC . This is key to get distributor installed right.
 

Chain has almost no slack as I expected as the motor has less than 60k kilometers on it. So just to eliminate the possibility I replaced the cap and rotor and plug wires....I was going to anyway. Found to have spark on 3 and 4 only but still not at right time. So back to an earlier question...Since I failed to mention something I just thought of....I ditched the stock auto transmission and shaped to a 5 speed from a 90 XJ. Used the 90 flywheel....will that matter?
 
I know I had to jump 2 wires together so it thought it was in neutral soi would crank over..but are the timing windows different on a 90 flywheel?
 
While I do not know if the flywheel is actually different , this is interesting . I didn't realize this before but good you mention it. Well , it's good the engine is low mileage and timing chain is tight which makes things easier and worth trying to get this engine running . This would explain why timing is not correct . I don't want to say the flywheel is wrong and the cause of your problem but I will say that research needs to be done now . First of all , we need to know that all matches . Taking into consideration that the crank sensor must be in right position , the windows on flywheel must be read in proper time so yes we must know that the flywheel , bell housing , and crank sensor all fit right and work together. It is one thing for these afore mentioned parts to bolt up , yet another that they are playing nice with each other. Now I fully understand why your concerned for mixed parts. It's easy to just say that all the parts are from a 4.0 liter and should just work. We are expecting that . But if there is any difference between model year and auto to manual , we need to know this too. I really do not know but this needs to be researched . The only question I have is when you installed the flywheel did you notice if there was something to indicate exactly what position the flywheel needs to be bolted on to the crank ? I do know that whether it's auto or manual trans , the flywheel must be installed correctly in relation to the crankshaft . I'm not presently certain if possible to actually bolt up,the flywheel to any bolt location or is it in some way keyed so the bolts will only go on of the right hole on the crank will align with the right hole on the flywheel . Let's understand , the flywheel windows will directly correspond to what cylinders they provide position for to the crank sensor so the PCM knows what cylinder is on compression stroke for correct firing order for ignition and fuel injection. This why the flywheel MUST be bolted on the crankshaft on the right holes. This is actually the equivalent of the distributor being 180 degrees or so off . The flywheel has windows that are so to speak "keyed" so the crank sensor can pick up,the magnetic pulses in a rhythm or wave length the PCM interprets so the correct cylinder is being told to PCM its on compression stroke ready to fire when the crankshaft is actually in that position and the piston is actually on compression stroke and ready to complete its power stroke. As far as worrying if the parts match regarding model , I believe your PCM is actually picking up,the signal so the crank sensor is being read . The only problem I fear is that I'm hoping the flywheel is bolted on in the correct position. Again , I'm not presently sure if a flywheel can actually be bolted on in the wrong position since it should somehow be keyed to,prevent that , but we still have a timing problem . We need to know if the flywheel is I the correct position and I've a feeling it may not be but need to know if it can only bolt on one way. Don't want to make you tear into it ( huge job , I know) on a guess. But this is real , the crank sensor does in fact tell PCM which cylinder is on compression stroke by reading the flywheel window positions and the cam sensor must start on number #1 for correct secondary ignition. It sounds like we are on to it now , but can you tell us if you recall whether there was more than one position the flywheel could bolt up ? I really hate to say you'll have to remount the flywheel to,get the positions right but it may be . Don't have the heart to tell you but it may be true.
 

Joshua Faas said:
I know I had to jump 2 wires together so it thought it was in neutral soi would crank over..but are the timing windows different on a 90 flywheel?
Click to expand...
You had to jump out the neutral safety switch so as to get the starter to crank . That's cool but can you run those wires to the clutch start with on down the road ? Will most likely have to lengthen them .
 
I suppose just for peace of mind I could stuff the automatic back in tomorrow just to see. It would answer that question at least.
 
Wouldn't want you to go through the trouble of swapping manual back to auto since you've no doubt done a fine job of installation so far. Want you to enjoy the manual and stay on course of your build . The issue is getting the newly installed engine running.
This problem shouldn't take a lab scope but we do need to go back to basics since it clear the firing order both ignition and fuel injection is starting on the wrong cylinder . It would lead someone to think that it has to do with a flywheel bolted on in the wrong position and windows are being read by the crank sensor in the wrong time. This isn't possible since engine designers have safe guarded against it by keying the crankshaft and flywheel both manual and auto not with a key slot like a balancer or pulley but hole spacing . No fear, any flywheel will only bolt up one way . So , the flywheel should not be reason why this engine isn't yet starting or at least running right . It just barely fires and runs on its own now. This seems to be clearly a firing order issue. But how ? This has been the issue for some time now . The issue is posed to the forum and plausible answers are welcome . The distributor is properly placed fully aware of the knowledge that proper installation is crucial and critical . The engine is of low mileage and has a good timing chain so valve timing is good. It ran well before . No reason it can't again. So far it's got a good PCM and crank sensor . Cam sensor is working too and distributor has been placed in correctly and every way other to dispel theory yet not a runner. We know any engine needs air , fuel and spark to start and run . Elementary . Sequential port fuel injection and ignition needs proper timing to start and run. Granted . What is missing ? The engine is placed on #1 TDC compression stroke and distributor installed , oil pump shaft correctly aligned rotor pointing to #1 cap tower , distributor bracket fast to block . Would you think it's 180 degrees out not firing right as prompted to ? No reason to think so . But the spark is occurring late . The distributor has already been flipped 180 degrees with no results , so that's been exhausted. The thread name and initial question asked is it a timing problem or is it a mis matched part . Can a flywheel from ANY year 4.0 liter RENIX or Chrysler auto or manual ( shouldn't make any difference ) work here ? This is the first question that needs confirmation to dispel or conquer . Firing order has to start correctly and the flywheel is where it starts. The distributor is the second place . What important piece of information is missing ? How about the 4.0 liter , are they all created equal ? Aside from high output , do they all fire the same degrees BTDC ? This has been asked by this member with full knowledge it is an important ingredient with respect to the engine , flywheel and distributor. Tune up books all read controlled by PCM and manual adjustment not possible. This means parts placement and selection is essential . I'm personally somewhere between stumped and recalling ideas that have gotten success in my past . There is always a simple answer not yet found. Anyone is welcome to fill in the blanks . This could happen to anyone . I'm standing by for it to happen to me and have to beat it to death as well. Please help if you've found or know what has been overlooked or not employed. In advance , thank you for your assistance .
 

I got to wondering about a cam upgrade my older brother did on his 4.0. He ended up having to drill a hole to move rotor placement to make the darn thing run. Hope I don't need to do that as its stock but...I did find a cam spread sheet which says the 96 and up cam changed.
http://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm

Not sure if that will point us in the right direction but worth a shot.
 
So , this engine's got a hot cam huh ! I don't know the lobe separation angle on the stock 4.0 but it seems the ignition may have to be degrees earlier since the intake valves are opening earlier . As you've said in an earlier post , the spark is coming in too late . Gee wiz , all this time I thought I we were dealing with a stone stock 4.0 ! Wow , what other tricks does this sleeper have ? Three angle valve job by any chance ? Wondering if the cylinder head has been through a machine shop ! You are on to something and yes , we'll need the recommended initial timing for this cam's profile. At least you've got papers on the cam's grind and a contact of which you can obtain this info . Last nite and this am I've been thinking of where else to turn which prompted me to put the call out to the forum if they see something we may have not seen. It happens , you get focused on basic items and don't leave to the imagination what else the problem could be. Guilty , I overlooked the obvious . All the basic checks didn't turn up anything overlooked and I guess it should have been obvious that the spark is coming in too late but didn't know why. If you were able to actually adjust dwell like a regular distributor , you would have just retard or advanced the distributor timing and got it to idle and start right. What ever can be obtained in terms of initial base timing or anything significant to setting up and adjustment in this application would most likely help immensely . Great ! Your just crack this case ! Good detective work !
 
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Well then that's good to know. I could drill a few extra Holes to test this theory in one of the extra distributor plates I have. Each a degree or so apart and see what happens. You would call that a "hot cam" then? I'm no professional mechanic so the numbers didn't mean much to me. I just noticed they were different.
 
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