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Discussion Starter · #1 ·
Transgo Kit, 2800 edge stall, 3.42 posi.

My wagon vibrates pretty bad any time the coverter is locked up and I give it gas. Doesn't matter how fast I am going. I don't really notice it in any other gear regardless of speed.

It was parked for a month while I worked on my exhaust and suspension and it didn't have this problem before. Any ideas?
 

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Check first for an engine misfire. You will feel this once the converter locks because otherwise the converter absorbs a lot of driveline vibration.
 

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Discussion Starter · #3 ·
Thanks for your input Sherlock.

I was hoping someone would say ignition. That is what I was thinking (or bad gas :D). Most likely I fried a wire trying to clear my afterburners. I'll check the plugs and wires first. I'd rather do that any day over a driveline problem!
 

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Discussion Starter · #5 ·
Sounds to me like the classic symptom of a converter going bad.
I sure hope not. The converter was recut by Andre @ Edge ~ 3000 miles ago. At least it's still got 1.5 years on the warranty if it is :D
 

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Sounds like TC shudder. Try using a tube of Lubegard Shudderfixx. It instantly cured the symptoms with mine and bought me about 20,000 more miles before having to replace the trans. It is one of the few(possibly only) additive type products that actually worked.
 

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Discussion Starter · #7 ·
Man I really hope it isn't the converter. How do you troubleshoot a bad converter? Could it be something like TC bolts? My fluid was a little low, but it was still above the COLD mark. Doubt that is what it is but I am still going to add a little fluid tonight to see if it helps.
 

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Discussion Starter · #8 ·
After replacing the wires the problem has still not gone away. I realize that engine misfire may be more complicated than just plug wires but I figured it was a start.

This may not belong in this section, but do I need to retune anything after getting a higher stall and TransGo kit? I am still running the same tune that I have been for a couple years. I'm just wondering about shift points and lockup RPM.

I'm also going to try that ShudderFixx tonight. I'm going to the Smoky Mountains this week and would love to take the wagon (since it has $4k in wheels/tires and suspension upgrades), but the vibration is just too annoying at the moment :(.
 

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Discussion Starter · #11 ·
Buffman,

I'm guessing higher lockup RPM with a higher stall? It really is much better above 75MPH, which is just around 2500RPM, which is 300 RPM less than the converter locks at. I would like to think that the converter would lock a little lower but I could see where it may be "slipping".

Anybody who has a 2800 coverter, when does your car go into lockup? Mine will do it as low as 1800, which was the stock stall if I am not mistaken.

Hmm, could be on to something...

-Derek
 

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Buffman,

I'm guessing higher lockup RPM with a higher stall? It really is much better above 75MPH, which is just around 2500RPM, which is 300 RPM less than the converter locks at. I would like to think that the converter would lock a little lower but I could see where it may be "slipping".

Anybody who has a 2800 coverter, when does your car go into lockup? Mine will do it as low as 1800, which was the stock stall if I am not mistaken.

Hmm, could be on to something...

-Derek
they're basically the same as stock maybe 3-5mph higher. IIRC my programming as lockup as low as 37mph in 3rd gear. The only other things to tune for are for idle and for keeping the converter locked at low tps input. Flexplate isn't cracked is it>?
 

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Discussion Starter · #13 ·
Well, looks like I should've looked into this earlier. Just got back from vacation and when I got off the exit today at work, the car started stumbling BAD. I managed to get into my work's parking lot and the car died. It will start back up, struggle to rev and die if I don't give it gas.

What should I look at first coverter or trans? I guess this could be a whole different issue, but it sure seems related.
 

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Doesn't sound like it would be a trans or converter issue if it won't rev and it struggles to stay a live, test typical things first, fuel pressure being one of them, I am not sure what happens when a converter dies, if it puts that much load on the motor and would cause that, I wouldn't think so. What you may find in the end that you had a stumble in the motor to begin with and what ever was causing it has failed.
 

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Discussion Starter · #15 ·
Good call, Mike

<20PSI of fuel pressure. cwm2

I can hear the fuel pump run, but pressure won't build past this. You can see it go up slowly, but won't ever reach past 20psi.

I disconnected the fuel pressure regulator vacuum hose and it isn't any different.

I personally replaced the fuel pump when I got the car 3 years ago (that is why the car was so cheap) with a Walbro 255 unit. Did the fuel filter at the same time.

What order should I troubleshoot?? Any ideas would be greatly appreciated. I was going to replace the fuel filter first (cheap fix) then try an extra fuel rail with regulator that I have laying around. Then finally the pump (if I have to). That is the beauty of having 2 LT1 powered cars. I can swap known working parts for a cheap overall fix.

Think that poor fuel pressure would be causing the original issue of vibration during lockup? Sounds possible to me...
 

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<20PSI of fuel pressure. cwm2

I can hear the fuel pump run, but pressure won't build past this. You can see it go up slowly, but won't ever reach past 20psi.

I disconnected the fuel pressure regulator vacuum hose and it isn't any different.

I personally replaced the fuel pump when I got the car 3 years ago (that is why the car was so cheap) with a Walbro 255 unit. Did the fuel filter at the same time.

What order should I troubleshoot?? Any ideas would be greatly appreciated. I was going to replace the fuel filter first (cheap fix) then try an extra fuel rail with regulator that I have laying around. Then finally the pump (if I have to). That is the beauty of having 2 LT1 powered cars. I can swap known working parts for a cheap overall fix.

Think that poor fuel pressure would be causing the original issue of vibration during lockup? Sounds possible to me...

You go to a seperate harness when you put the walbro in? You check the bulkhead connector?
 

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Discussion Starter · #17 ·
No, just the pump. I don't remember it very well, but is the bulkhead connector on the outside of the gas tank or are you talking about where it plugs into pump inside the tank?
 

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Discussion Starter · #19 ·
Fuel Pump Relay

Kinda weird for that to go out, but at least it was free.

Still shaking under 65 MPH on the highway when locked up though.
 

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In that month that it sat, what did you do to your suspension? Did you take your driveshaft off to work on your exhaust? Did you put enough exhaust hangers on there?
 
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