Help with the simmy shake(not the dance)?

[sy1907]

Syty patrons, I got a doozie. In a nut shell, I have been trying to pin down this shake for a few months. Any ideas would be greatly appreciated! A little something like this:
I have a stock syclone except for the exhaust which was replaced by the previous owner. Ever since I had it on jack stands for 3 weeks, it has ran with a horrible shudder. The only thing I replaced was the transfer case when it was up. NE ways, I, with the help of Buster, checked the fuel return lines, replaced the fpr, replaced plugs, wires, cap, and rotor, ohmed the injectors, checked the intake for cracks and bad gasket, and have found nothing. Buster put the wideband 02 on it, finding it running extremely lean (18:1) about. What in the hell is causing this? Even though there is good pressure at the rail (43psi), it is still running lean. I heard it was wrong to use injector cleaner, what does it exactly hurt? Seriously, I really want to get this squared away b4 winter, which is already here, so any help would be appreciated. A big thanks to all and Buster( 11.0 @ 122).

 

[canadian]

Did you take the propshaft out when you replaced the transfer case? If so, take it out again and see if you get the shudder, if it goes away, maybe you put the propshaft back in 180* off?

 

[sy1907]

Yeah, but that was rebuilt and balanced. NE ways, it does it when it's in park or nuetral with the engine just reved up. When driving, the drive train seems good though, any thing else pop into your head?

 

[syclonekid43]

did you check for a crossed wire it all depends what wires got crossed (if thats the problem) you might not really fell it when you get in to the gas alitle or check to se it the plug wires are on the plug some times the wire goes between the plug and the heat shield and you dont know it happened i did that a few times how was the truck running before you did all of this did you try to change the fuel filter maybe a wire got burnt a little its kinda hard to say with out the truck in front of me figure i shoot a few things at you try them out a let me know

 

[sy1907]

I checked about 3 times and was rechecked by a buddy of mine, all good there on the wiring. Before I put the truck up for repair, it ran really good with the exception of a broken intercooler that I got repaired and replaced while it was up. Other than that, it was as smooth as a sy can be. I thought I might change the fuel filter in a while for shitz and giggles, even though the pressure at the rail is correct. Basically, it ran like shiz after sitting for 3 weeks. It's got me in the bag right now.

 

[syclonekid43]

did you check for any broken vac lines on it or maybe one got unpluged when you guys were under the hood do have any plugs for sensors that have a broken clip on them were they dont lock togrther that nmaybe came apart im tring to throw you stuff but im running out them

 

[Fred Aldrich]

Sounds to me like a serious mis-fire. Lean readings come from the oxygen that is just going straight through a cylinder that's not firing. Ground out the plug wires one at a time to locate the bad cylinder.

 

[sy1907]

At the shop I had it at, a random misfire was possibly detected, but the cap and rotor where changed, and the misfire prob was gone, but the shaking was still there. Supposidly the injectors ohmed fine, what running cleaner through them kill the engine? (I know it's not the greatest)

 

[bdubb]

is the timing set correct?

 

[sy1907]

Would the timing have gotten messed up from sitting for 3 weeks? My gut tells me nay. Ran good before sitting, first start after, prob started.

 

[Blake]

Let me know what you find out. I'm leaning toward a broken mount of some kind. Mine started about 2 weeks after my tranny had to be rebuilt. (My 9/11 TC took a dump and filled the trans up with metal). I'm thinking that they let the tranny hang from the engine mounts during the removal/install thus breaking one of the engine mounts. The engine mounts were NOT meant to take the twist/weight of the transmission and transfer case hanging from them.
I've done the same deal, new plugs,wires,cap,rotor button,checked fuel pressure,checked for bleed down(just haven't done a new compression check) with no luck.
Let me know if you find out anything. Mine was only up in the the air about 4 days on that one.
Thanks,
Blake
PS: Forgot to add, one of the old timers on this list advised me that letting the tranny hang from the engine mounts also puts stress on other bad things as well(distributer hitting the firewall, wires getting pulled on, vac lines getting broken from being pulled on, fan hitting the fan shroud and getting bent, etc.)

 

[canadian]

go down to autozone and grab a set of the cheapie lifetime warranty wires and put them on. i had one burn on the dowpipe and it felt like the tranny was taking a dump. put them on and it fixed the problem until i could get some real wires. since they're lifetime warranty take 'em back and get your money back or keep them for emergencies.

 

[bdubb]

Would the timing have gotten messed up from sitting for 3 weeks? My gut tells me nay. Ran good before sitting, first start after, prob started.

well it doesnt hurt to make sure anyways. if the bolt was loose, and the tranny out, the distrubtor could hit the firewall and put it out of wack.

but i'm just throwing out ideas to try to help.

 

[sy1907]

I wasn't messin with the tranny at all, and I had the same ground out on the down pipe prob before. Quick fixed that, helped a bit. I did notice that when I'm on the gas, the shimmy is there really bad, but when I let off and just coast, it pretty much is undetectable, then comes right back when I get on the gas at all. Same story in nuetral. When I torque the engine, it sounds and looks fine from outside, like no mounts are broken either. hmmmmm?

 

[BillC]

Have you checked the fuel filter? If it's clogged, that could account for the lack of fuel. If it hasn't been changed in a while, you should probably do it anyway -- it is an often-overlooked maintenance item.

 

[sy1907]

I was planning on replacing it soon just as a maintenance issue, but there is no lack of fuel. At rail, there is correct pressure at idle and under and at 16lbs of boost, me and buster checked that. But yeah, I'll do that after I get this squared away hopefully. Ideas................?