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Hello, I have just replaced the timming chain on my 3.9L engine because of to much play and chattering noise. I placed the #1cyl at TDC on the compression stroke and lined up the Cam and Crank marks as per specs. When I took off the distributor cap, the Rotor was pointing to #4cylinder. I rotated the cam around again to make sure the valves were in the compression position and they were. So I removed the distributor and rotated it to the #1 position and tried to start it. After several attempts of cranking it would not start. I then rotated the distributor so the rotor was again pointing to #4cyl and it started right up. Using the timing light, the marks are not even close! But the vacum gauge shows everything is normal. The problem is that while the engine does not hesitate or miss fire and runs quite well, there is a bit of roughness sort of like a shutter or vibration you can feel at 30mph and above. I'm quite sure it is from the engine. Any ideas on this would be appreciated.  

you have to explain more what this vibration is. Maybe the engine mounts?
if the engine runs good up to 30 mph nad then shudders,,i need more info.  

Hi and thanks for the reply. Its one of those hard to explain things but one that you notice when you are very "in tune with your vehicle" so to speak. Have you ever experienced the vibration from a bad U-joint. This is not like the whole van shakes but just a slight roughness you can feel. If you coast down a hill in neutral for test purposes it is not there. Perhaps it is the motor mounts, but this out of sync thing with the timing is bugging me.  

please check back here later as I may have some ideas.

If you figujre it out before me please post the solution.

I have already read your post several times  and I still haven't figured out how a crank and cam that's set for #1 will only fire on #4 dist setting.
Actually it won't but it does. And I know you already checked out the spark plug wires for the proper order. So that's out.  

Thanks again. Here is another reply from another forum which I couldn't do much with. Please bear in mind that I am only a do it yourselfer and buy no means a qualified mechanic!
Sounds like the distributor is indexed incorrectly This would cause problems with the cam and crank sensor sync. I recommend finding compression on #1 cylinder then bring it to top dead center on the crank marks. I Would then remove the distributor and and turn it to align with the #1 spark plug wire. The oil pump drive will need to be moved using a screwdriver to allow it to line up. Inspect the bottom of the dist. to help with alignment. After the engine is running correctly and warmned the dist needs to be adjusted for sync. Bring the engine up to #1 TDC again. Loosen the dist. bolt and slow turn the dirt until you can hear the relays click in the fuse box. This signals that the cam sensor is moving past the "window" timing slot in the Dist. So you are trying to get the dist turned counter clockwise just until the relay clicks. You of course would start clockwise of the point. That way you are very close to 0 deg sync. If you need more help. Just ask, You can also do this adjustment using many types of scanners.
How would you turn the oil pump drive with a screw driver? Tried turning the distributer and listening for relay clicks but no good.  

You never mentioned the year and make of the vehivle. I have been assuming its an older one because you mention a distributor,,,It could also mean you have a carbuerator . Its a v8 right?? so you have two cams?
I have a little library here but I dont know what I should be looking up.  

Hello, the year and make are in the thread title but anyway it is a 1994 Dodge B250 van with a 3.9L 6cyl SOHC. Thanks for any suggestions in advance.  

I don't know how the h*** missed that.
I don't have anything in writing on you vehicle. But I did go to Autozone.com and look it up on thier free repair guide,,and fortunately they have one for this model. Seems that this engine was the midpoint crossover from mechanical to electronic, because tere is still a mechanical distributor but it is teamed up with a camshaft sensor and a crankshaft sensor. (the camshaft sensor is on the distributor and not the camshaft --where you might expect it to be).
I said it before and I'll say it again. No way can the you have the engine and distributor set for different pistons and expect it to run. There has to be something wrong. Maybe the plug wires  are wrong on the dist. cap.I don't know.

Anyway,,there a real good repair guide on Autozone.com. It may be worded and organized differently than the manual you have at home and that may give you a different insight into your thinking and be helpful.If you go there you just plug in your cars info.  

Yes that info is all correct. As far as Autozone goes that has been on my favorites list for a while.  I may just get the short block rebuilt soon anyway and then let them straighten it out. Thanks for trying anyway.  

How are you counting the cylinders on the 3.9 V-6 engine? Number one is at the left front. The cylinders are numbered 1-3-5 on the left bank and 2-4-6 on the right. The timing marks on the crank and cam gears should be aligned toward each other . With the timing mark on the crank gear facing up and the mark on the cam gear facing down,the engine is set at TDC on numbers one and two cylinder and the distributer rotor should align with the number one plug wire terminal in the distributer cap. I don't suppose the rotor was pointing toward the number four spark plug,which is located second from the front of the engine on the right side?
Best regards: JRTA  

A 3.9 is not an eight cylinder ,it is a V-6. If you have a B-250 van it most likely has a 5.9L V-8 .Dodge has three engines for the van and pickup applactions: 3.9 V-6 ,5.2 V-8 and 5.9 V-8 But does not put the 3.9 in a 250 series,it it too small for the load.
Regards: JRTA