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I just finished my ZF swap. while she was down I went ahead and did the timing sixliter bump/igntion upgrade, and put on my shortie headers. The way my dual exhaust was routed behind the T-case, i can no longer use my exhaust, so I only have straight headers on it for now. Anyway, I couldn't wait anymore, just had to go for a spin and try out the new tranny. But now she backfires and spits and spudders like crazy! I've heard that no exhaust can make it do that, but kinda leaning toward the timing part of it.

My Haynes says my 89 5.0 should run at 0 degrees timing. But it was set at 10 degrees like the newer FSB's (I'm 90% sure) after last rebuild. So I bumped it up to 13 degrees. I had didn't have time to reset the timing today because of work, and it will be tuesday before I get around to it. I'm going to set it back to 0 and go from there. Just wondering if the no exhaust issue is my main problem.

The motor also felt really week, but I did move from 33's to 37's while I had her torn down. But I didn't expect much of a change since going from an AOD to the ZF5, I actually expected much more low end grunt with the 5.72 1st gear ratio. Any thoughts???
 

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My Haynes says my 89 5.0 should run at 0 degrees timing. But it was set at 10 degrees like the newer FSB's (I'm 90% sure) after last rebuild. So I bumped it up to 13 degrees. I had didn't have time to reset the timing today because of work, and it will be tuesday before I get around to it. I'm going to set it back to 0 and go from there. Just wondering if the no exhaust issue is my main problem.

Any thoughts???
No it should not bet set at 0*. That must be a typo in your book. Factory setting is 10* BTC Are you sure you didn't set it to 13* ATC? Sixlitre timing bump is 13* BTC
 

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You've got no backpressure/scavenging with out the rest of the exhaust system. It's gunna be really loud and sound like a drag car but it won't have any torque and she's gunna "backfire, spit and shudder like crazy".
 

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You've got no backpressure/scavenging with out the rest of the exhaust system. It's gunna be really loud and sound like a drag car but it won't have any torque and she's gunna "backfire, spit and shudder like crazy".
No it wont. Just becuase you are running open headers doesnt mean it is going to run like crap.
 

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I have to agree with timing, I ran my truck on open headers for a few days while i was gathering parts for exhaust and the only time I got a backfire was a high RPM downshift (5 spd). heh it was always fun to do that next to people walking.... makes them think they were getting shot at:toothless
 

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longtubes can be run open, idk about shorties tho.... i mean long tubes have reducers and create enough back pressure usually, but as far as shorties....
 

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triple check your plug wiring is 100% correct
:stupid
Double-check your firing order. If any of them are out of order, it'll run rough and backfire. Also, be sure you're using the correct order for your engine. There were two different firing orders for the 5.0 engine. If you use the wrong one, it'll run, but not good. Don't ask me how I know :doh0715:
 

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'94-up is 1-3-7-2-6-5-4-8, I don't know which one yours is, just don't use that one use the other one and you'll be good.
 
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