Quite possibly the best day of my life.

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1low4x4

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Nick
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1984
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K10
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5.7
No, not a divorce or marriage. Not the lottery. Not my firstborn.

I fixed my truck.

Ever since I Installed the 4L80e I have had neck snapping shifts, truck shifting into OD at 35mph leaving me virtually no acceleration or pulling power for my bigass pontoon. plus it would NEVER downshift. I tried fooling with the handheld controller to no avail. Called my trans guy and he said he went through the entire trans when he rebuilt it.

Kept having problems with the tps bracketry on the carb, at one point it actually fell off and for months I drove without it unknowingly. The trans acted the same with or with out it. I had unhooked the handheld after initial setup so I couldn't see the code, and couldn't see the flashing blue led indicating a code because the computer is mounted in the engine bay.

So I looked for ways to build more power...thinking the trans was just...what it was. I installed the vortec heads and cam as shown in another thread, and got definitely more compression but truck drove the same. Truck much louder. But no more power. Very disappointing.

Fast forward to today. Thinking of pulling the 350 and installing a 6.0. I was desperate. Even thought of swapping my drivetrain into my blue 85 short wide to see if it did better. Decided to call TCI and cuss them because it takes 20 days to get a response on their forum.

Called and talked to "Ricky". Explained my problems. Told him every setting, every rpm at what speed, what it was doing and what it wouldn't do. He said check tps sensor. He said at idle it has to read at least .1V and at WOT it can't read past 4.9V. Said to check it with a volt meter using the wire provided with the sensor for that purpose.

So I did. My sensor was set way off, it read real high on idle and maxed out on WOT which threw a code which sent line pressure thru the roof. Which gave me neck snapping shifts.

I drove the truck having readjusted the tps linkage to do what he said. It shifted like a CADILLAC.

I was excited as hell. I've spent $3300 on this swap trans and computer included, and here it was all coming together a year later.

At that point I decided to pull th manual for the ez tcu out and go through the settings again. Before I didn't matter where I set them, with the tps ****** it never worked right.

So with the neck snapping shifts gone, next was the fact that it still wouldn't downshift when pedal was mashed. Soon figured out that 'Max shift rpm' was set at 2500. This explained why the truck would downshift into 3rd for a split second and then once it reached 2500 rpm it slammed back into 4th. I reset that at 4200 rpm. Now, the truck downshifts BEAUTIFULLY. Push the pedal down and she jumps into third and SCOOTS until you either throttle out and let it shift or until it reaches 4200 rpm. I love it.

Last problem I had was that the damn thing shifted through all gears into overdrive by 35 mph. This left my truck like a turd. The 'shift aggressiveness' was set low...I moved it a few times before settling on setting 3...this allows the trans to drag out shift points much longer and now its like two different modes depending on how I drive. If I take off normally, the trans shifts smoothly and shifts drags out 2 and 3 longer allowing it to shift around 45 I to OD. Very nice.

If I get on it and leave quick it shifts a little firmer, and brings shift points even longer out, and shifts around 55 into OD.

SO much more power. Truck feels like a bullet compared to before. That trans going thru the gears so quickly left me no power. I can't wait to pull the boat.

Needless to say I am very content with my 350 now that the trans is acting right.
 

Old77

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Nicely done man!!!
 

Old77

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X2 on being back on the forum :hands:
 

Jims86

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Jim
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1986
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K10 Suburban Silverado
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5.7 TBI
Most swaps endure problems in the first year, unless you have a full, Uninterrupted 2 or so weeks to test and tune.
Glad you got it figured out!
 

Driver4r

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355/th350/np203, 454/th350/ff-rear
GREAT news to hear.
 

1low4x4

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Thanks guys. Today I adjusted the max tps thingy which allows the truck to not up and downshift so damn much. It was downshifting at light throttle, tps was set at like 40%. I changed it to 79%. Much better.

I'm enjoying the new power. Ask me how to burn 1/4 tank of gas in 35 highway miles
 
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Driver4r

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k10,c20
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355/th350/np203, 454/th350/ff-rear
Thanks guys. Today I adjusted the max tps thingy which allows the truck to not up and downshift so damn much. It was downshifting at light throttle, tps was set at like 40%. I changed it to 79%. Much better.

I'm enjoying the new power. Ask me how to burn 1/4 tank of gas in 35 highway miles

Drive my truck with the 4.11's. It could do better if you punch it and kick it down to 2nd.
 

HotRodPC

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454 - Turbo 400 - 3.73
All of this explains why your mpg was in the ******* too. With all those changes, I wouldn't be surprised if you don't see a 3 mpg gain.
 

1low4x4

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Currently on a gas mileage quest now. Filled uo last night and drove in to work, 70 moh all the way converter never unlocked. Gonna run the tank down and calculate again. This will be a.real world gas mileage reading with city and hwy
 

Snoots

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Roger
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1973
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Jimmy Sierra
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350
Great that you got it done the way you like it! Thank you for sharing the info and welcome back.

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Honky Kong jr

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Lil BB 407
If I thought they put something that good in it I may consider it.


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