How do I correctly bolt a flexplate to a torque converter?

Hi, this is my first post and I'm new to Ram Forum. Before I get into the flexplate issue I wanted ya'll to hear what I've been doing to the truck over the past year.
You can skip that part and just look at the PROBLEM section if you choose to do so, unless you want to hear a good story.



Introduction of the rebuild:

I have a 1997 RAM 1500 5.9L 360 SPORT STANDARD CAB SHORTBED... Last year around October, I decided to rebuild the engine in my truck at almost 130,000 miles. The two previous owners really ran this truck rough. The guy I bought it from told me the first owner of this truck was a farmer in the Emporia, KS area.
This is my first rebuild EVER! I completely overhauled the engine + transmission with the help of a buddy. He has a big job, so he couldn't help me anymore after that. I worked on it BY MYSELF for many days and nights, on and off, over this past year. Of course, procrastination took it's toll and that's why it took over a full year to be finished.
I had it machined and it was bored .030 over I believe... I had him do a half rebuild for beginners sake because I did not have the proper tools to do some of the build. Basically he put in the crankshaft, camshaft, pistons etc.
With the machining, half rebuild, checking my heads for cracks, cleaning etc. the service cost was $600...
Of course, I had cracked heads, so it's time to order new parts. I ordered remanufactured heads, a full engine rebuild kit along with fresh new lifters, full gasket kit etc. It had a bad starter, so I bought a new one from AutoZone.
I paid much attention to detail when putting it together. Basically every bolt was torqued to spec, thread-locked when needed, sequences, everything. When I have sufficient funds, I'll probably replace the transmission. It's not bad, I just want the system to be fresh.
Then, all by myself, with my engine hoist I manuevered the engine + trans into the engine bay. I'll tell you, this SUCKED the most. Doing it alone is challenging and not recommended. I basically had to put a jack with wood blocks up to the transmission, so it will angle onto the cross member and sit inside the engine mount slots.
Lastly, I just banged out all the wiring, cooler lines, a/c lines, installed the a/c condensor, radiator, hoses, fan etc.

I cranked it for the first time the other day at she's alive!!! But here was the problem...





*PROBLEM*:
(1997 RAM 1500 5.9L 360 SPORT STANDARD CAB SHORTBED)
I don't think I bolted the flexplate to the torque converter correctly, so I think the engine is unbalanced. The reason is I just couldn't find any information on how to do it correctly and was going to figure it out through trial and error once it was put together and here I am....
SYMPTOMS: the idle fluctuates erratically between 500-1500 rpm and eventually shuts itself off. The first few seconds seem fine until it starts speeding up and down.
(I ran it 4 times, a few seconds each, to see the symptoms and stopped to prevent any damage)
NOTE: the flexplate uses weights, so I believe the engine is externally balanced.


Any thoughts, questions, comments, and concerns will help a lot. Thanks guys!

While it is running do you hear any unusual noises such as a knocking or scraping sounds? Besides the fluctuations in idle does it run smoothly? Is it skipping? It sounds like there may be a vacuum leak or a sensor problem. Is the check engine light on? If so then check to see what codes are stored.

The pcm has to rekearn all the new sensors and may act funny throughout the process. May need to be run for several minutes to level it out.

I'm not sure on break in procedures but we have the wonderful factory service manual available for download in the diy section. If look it up and get you a page number and all but I'm at work on my phone lol

Rlaf75 said:

While it is running do you hear any unusual noises such as a knocking or scraping sounds? Besides the fluctuations in idle does it run smoothly? Is it skipping? It sounds like there may be a vacuum leak or a sensor problem. Is the check engine light on? If so then check to see what codes are stored.

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No scraping, knocking, or anything. It just fluctuates and eventually turns itself off. Will check the codes tomorrow

did u have the dizzy out? if so fuel sync needs to be set.

don't know that much about the Magnum small blocks, but the LA 360's did not have weighted flex plates. the converter had the weights welded on to it. that said, I'd agree with the previous comments about vacuum leak(s), and giving the computer time to learn.

Well you need to brush up on the maggy motor cause they do have weights welded to the flexplate.

if that is the case, then I would presume the flex plate can only go on one way. It should be idiot proof, and can't be the problem. If the Magnums have offset weighted front dampeners, the elastomeric can give up, and allow the outside ring to slip and cause a shaking issue. It's a bit of a long shot, but it could happen.

Rustycowl69 said:

if that is the case, then I would presume the flex plate can only go on one way. It should be idiot proof, and can't be the problem. If the Magnums have offset weighted front dampeners, the elastomeric can give up, and allow the outside ring to slip and cause a shaking issue. It's a bit of a long shot, but it could happen.

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.....

Hey everyone, I forgot to update ya'll, but I found the problem!

Basically, the flexplate/torque converter had nothing to do with it, the firing order was off. After doing some reading through the service manual, I had a hunch that I did not put the distributor and/or spark plug firing order on correctly. In that case, I took the distributor off, set the engine to TDC and reset the distributor to line up with the hash mark. Put everything nack together and it ran smooth as ever, no problems.


Thank you all for your feedback it really helps alot!

This is HALF of the fuel sync Merc was talking about. Now you gotta do the other half which is get it hooked up to a snap-on mt2500 or dealer DRB3. This will make it so it can be perfected. Most will recommend +2 to +4 degrees of advance on it

I think we all have been there done that over the years doing old time tune ups. I know I have.

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glad to hear you're back on the road. thanks for following up and letting everyone know the resolution.

dapepper9 said:

This is HALF of the fuel sync Merc was talking about. Now you gotta do the other half which is get it hooked up to a snap-on mt2500 or dealer DRB3. This will make it so it can be perfected. Most will recommend +2 to +4 degrees of advance on it

Click to expand...

Your 100% right fuel sync needs to be set...........but as it's "running" chances are it won't get done, seen this lots. You know why spend a hun when it runs right. Just like many think turning the dizzy changes the timing when in fact it does not.

Only cost me 49.99

But they only set mine to 0 degrees