Adjustment help

[smokin69]

Well I just got my a new IP and injectors put in it this week, only took me about 3 1/2 hours total working time to do it all, anyways I need some help figuring out how to adjust the governer speed, as it's right at 3300 rpm right now and I'd like to be more 35-3600 as the extra few rpms really help on the upshift pulling a lot of the bluffs around here. I also was wondering if anyone knew how to do all the adjustments on a C6 because mine shifts like ass and acts like my foots mashed to the floor all the time and won't shift untill 2500 rpm everytime for both shifts.

 

[icanfixall]

 

[Agnem]

3300 is the governed speed because horsepower drops off beyond that. Torque drops off a lot earlier. As Dyoung has proven, asking more from your motor without compensating elsewhere is a recipie for failure.

 

[LCAM-01XA]

No idea on the overspeed governor adjustment, but mine is at 3800 rpms and like Mel said there don't seem to be any power gains over 3200-3300 rpms. I could see the need for some extra engine speed for upshifting while pulling a grade tho...

About the C6, make sure your vacuum lines from the vacuum tree on the firewall to the VRV on the IP, and then from the VRV back and down to the transmission are all intact - a vacuum leak somewhere in this system will result in the pressure modulator in the trans "thinking" you're running under heavy throttle and jack up the line pressure respectively, hence the late (nd probably quite harsh) upshifts.

 

[smokin69]

I've checked the lines and they seem good, I had the VRV off when I was switching pumps and misplaced one of the screws and left it off when I went to go pick another up and the truck ran good and shifted really quick under light throttle but I could tell it was slipping if I rolled into it more. The little nipples on the throttle rod on the ip don't touch the VRV for the first little bit of movement but then it turns it. Is there a way to properly adjust it? As for engine rpm, with the last IP it would run right up to the 3500 mark and it really made a difference on a big hill I have to pull everyday because it let me down shift and run up the hill at 55 still but now I have to either hit the hill at about 65-70 or slow down to 45 ish and either one sucks.

 

[plywood]

This is from TDS and was credited to James, I'm not sure who that is and don't know the validity of it but it's the best I got.

Oh, and as far as I know there is know way for the VRV to cause slipping in an otherwise good tranny. Also check your kickdown rod to see it's right.

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You don't have the engine running for the test, you need to apply 20" vacuum (Hg) to upper VRV port and attach vacuum gauge to lower VRV port. The lower port is the one that goes to tranny, the upper to vacuum pump.
You have to maintain 20" vacuum (Hg) througout this test. If it drops off you need to pump it back up.
Remove throttle return spring, cycle throttle lever 5 times from idle to WOT. Make sure 20" vacuum is maintained on upper port side.
Move throttle so it is 0.515" (33/64") from wide open (they make a tool for this). Vacuum gauge should read from 6-8" of vacuum (Hg). If incorrect adjust VRV to 7".
Again apply 20" vacuum, cycle throttle from idle to WOT 5 times. Return to idle. Gauge should read at least 13".

It says if you can't get the 7" or the 13" to replace the VRV. If VRV checks out maybe the diaphragm (modulator), line from VRV goes to the vacuum diaphragm I believe. Can't find any adjustment for the diaphragm but I think there is a little.

Basically all you need for the test is a vacuum pump (handheld type), vacuum gauge and a ruler to measure 1/2" or a 33/64" drill bit in lieu of the .515" tool. And a screwdriver for any adjustment needed.
Good Luck
James

Note..... 20" vacuum Hg is equal to MINUS 65 Kpa..........

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[smokin69]

Hmm I'll have to try that, the VRV is almost new so we'll have to see, my old one broke. Thanks

 

[dyoung14]

More RPM, well if its a new pump you just bought then it has a warranty correct? well then you cant turn the rpm up till your warranty runs out, I actually have the governor spring that your looking for, the one out of my rebuilt IP that i burned down about a week before my warranty run out but it had s spring that would let it spin maybe a little past 3800 if you pushed the clutch in and floared it, but it will only spin about 3500 if your in gear and floar it, if you want that spring then 10 dollars and its yours, i paid 18 for my high rev spring and that thing aint going anywere just cant beat the way an IDI sounds revving 4500

Anyway if you want the spring its yours and i can tell you how to put it in its not hard