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87 K5 350 Auto w/"RV Cam" Power Spike

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CaliCuredCustoms

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I recently inherited my 87K5 which has a bunch of little things wrong (Cluster Gauges/Lights, TV Cable Adjustment) nothing too major, I replaced most sensors, ECT, MAP, O², but not the TPS. Finally bit the bullet and replaced the fuel pump due to gauge not working and she came to life!!! But now I have noticed at high rpm (no gauge, guessing 4k) there is a SIGNIFICANT POWER INCREASE, kind of like VTEC, but she opens up and it throws you back, im talking a nice KICK then WHAAAAAAA, sounds and feels AMAZING and then i have to let off. Any ideas what could cause that? And is there a way to have that (significant) power increase throughout the entire RPM Range... because just wow, the difference.
 
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What gear is it doing it in? All? Only at freeway speed or low speed.

It should have a 700R4 with a lockup converter. It locks in OD, but shouldn't wait until 4k. I would bet the RPM hit is lower than you think. 4K is about at valve float on a stock 5.7TBI engine. Ask me how I know.
 
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Wes Harden said:
Tbi or computer controled carb, (CCC) or reg carb?

Title has "RV" cam any specs?
Becsure that tv cable adjust is spot on, trans damage will occur if it's not.
Click to expand...
Computer Controled Throttle Body Injection...
Tv cable has been double and triple checked/set.
I recently inherited it from my grandfather who's had it basically "barned" unless he towed the boat to the river. So, all I know is he mentioned a cracked block by the freeze plug (I believe he said its common with these years/blocks... but idk...) which lead to him replacing the block and the "family mechanic" recommended i guess a "stock" rv cam for that motor since it only tows and climbs a levee on occasion.

###NEWS UPDATE!!!!###

I Completely Lost 2nd & 4th gear.
I know everyone says that's weird, haven't seen em skip gears ect. I did just purchase a new "corvette servo" kit w/seals so I'm going to install that and see what happens.

As far as the POWER INCREASE it happens in all... well... 1st AND 3rd gear.
And your 100% im probably EXTREMELY off on the RPM Range... I'm used to driving my commuter/Acura that goes to 5k when it engages VTEC and opens up to 9.5k RPM hahaha.
I have a theory - a LOOOOTTTT of Electronics (Mostly just Switches) are None Functional, radio, wipers, hazards, window/door locks, but as I use them more and more, some of them are starting to work again. I'm wondering it there is a possibility that my Disi's Vacuum Advance may have been stuck/sticky and it only operates with high vacuum. Because on my last drive i swear I felt a lower rpm power curve Adjustment. Maybe it is now 'unstuck'...? - ALSO, I have been working on the Dash/Cluster and I know the computer gets it's speed input from the back of the speedo which hasn't necessarily been plugged in. So maybe base map doesn't vac adv and that's why I'm feeling it? (Cluster installed last night)

Thanks for Input! My grandfather has had it since 89, I'm definitely keeping it. I really want to get it back to tip top condition, visually and performance wise. Looking like i might need a transmission rebuild but hey...
 
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So tbi shouldn't have vac advance at dizzy.

Start with basics. Vacuum leaks are very common. After sitting for some time everyting needs to checked.
Look for wiring damage. Rodents like to chee on wires.
Vacuum lines,tbi base gasket need inspection/renew. IAC motor and passage operation and flow.
Base timing set 0-2° btdc.

New fuel filter. Every 10-15k miles,or 1 year.
 
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I did not change the TPS, EGR, or IACV.
I am
Have replaced fuel pump + filter, MAP, ECT, O², Disi Cap/Rotor, Plugs, Wires.
Visually checked wires/vacuum lines, found 1 wire to coolant sensor grounding out that i fixed, I've even smoke tested it and found no leaks.

I'll go talk to the engine builder about the cam/chip.
And as far as vac adv disi I was just assuming.

Anyone know is the servo blowing a seal out could cause the tranny to skip 2nd and not even try 4th? Or is it a clutch/band issue?
Thanks again!
 
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There is a band that engages 2nd and 4th...probably lost pressure to engage the circuit in the valve body, smoked the band.
 
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