Can't adjust c6 shift points?

[Cubey]

It has been annoying me, shifting to 2nd at 25 and 3rd at 35-40. I bought a new, adjustable modulator valve from Oreilly (green stripe) because the one it had was non-adjustable. I guess the trans was a bit low on fluid, nothing more than a few drips came out when I pulled the old one. I have topped it off since. Leaving the new MV at it's factory setting, the transmission acted the same. I turned the screw out (presumabley) counter clockwise about 3 quarters of a turn. Still acts the same.

Turn it out more? Maybe the rod is too long? Maybe it has an odd shift kit to make it have those shift points?

It's annoying to be in 2nd gear at 30mph around town and in 1st gear at 15-20mph in parks. I have to be slightly lead footed with it to make sure I don't end up "stuck" in a lower gear too long, wasting fuel until I get to 25-27 or 35-40.

 

[Black dawg]

Have you adjusted the vrv?

 

[Cubey]

Have you adjusted the vrv?

Argh I keep forgetting about that being adjustable too, despite me trying over a month ago. (hooray for crap memory!)

I couldn't get a good bite on the screws with a screwdriver to loosen them. I tried a low profile, angled ratcheting one too, still no luck. I guess I need to go back and fight with that.

At least I isolated the MV as a possible problem. I had $10 off $20 and I got some other stuff I wanted/needed in addition to it, so basically the extra stuff was almost free.

 

[riphip]

Try a square drive driver instead on the screws

 

[Clb]

Vrv for the win
Perhaps put a different fastener in that is easier to access???
Now play with the timing with the green stripe at standard (zero setting) git the vrv to shift the way you want, lock it down, call it good.
Now you can tailor the shifts with the green stripe

 

[Cubey]

Vrv for the win
Perhaps put a different fastener in that is easier to access???

I have to get what's in there loose first, thats the problem!

 

[Cubey]

Try a square drive driver instead on the screws

It's very much obstructed in the van body, that's the real problem. As I recall, I think it only even has one screw in it, they probably dropped or just never put back the other because it's so hard to get at.

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[genscripter]

Yeah, getting to the VRV in the IDI van is a PITA, with that darn fuel filter in the way. I bought R&D's framerail dual filters and put them on the frame by the C6 crossmember, and that opened up a lot of real estate.

I've been kind of obsessed with VRV's lately, and I kinda know a lot about them. If it truly doesn't have the second anchor screw installed, you should do that ASAP. The cam turns based on a radially-installed pin thru the throttle mechanism. If the VRV is not mounted well, then the pin will turn the cam on an eccentricity, and likely cause premature wear. Also, turning that off kilter probably is causing housing strain or damage. And ultimately, it'll break that VRV.

Since you will likely need to pull the fuel filter, it might be time to upgrade to the framerail style fuel filter setup. Here's how I set up mine on my '88 Clubwagon: http://www.nickpisca.com/diesel/fue...ed-e-pump-sensors-and-frame-rail-dual-filter/

Then you will be able to access your driver's side engine stuff (like for cracking injectors, accessing GP's, etc etc...)

If you adjust your VRV and still have issues, or that VRV is broken, message me. I can inspect it for you and calibrate/rebuild if necessary.

 

[Cubey]

I'm having air intrusion overnight again and it's not even cold. Not sure if an oring got damaged and already failed or if it's another issue. Only the first start of the day, it starts, idles 10 seconds or so, then stalls and needs cranking. What a pain. Totally unrelated to the topic at hand but yeah. It was perfect for weeks after I did the return lines and orings so i dunno what the problem is now.

 

[Cubey]

I managed to get the one screw out. It's normal 1/4" threads. I got some stainless steel hex head bolts and metric washers (same size as the one with the old screw) and tried adjusting it. It's still shifting the same, 25 and 40.

But at least you can adjust it by loosening the bolts with a typical 11mm wrench without removing the fuel filter now. It has a bolt on both sides too, so that's an improvement too.

I'm going to leave it well enough alone for now. I have more pressing issues popping up here and there to worry about.

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[genscripter]

If your modulator is functioning fine, and your vac pump is ok, and you don't have any vac leaks in your hoses, and you have tried adjusting the VRV on the IP in various rotations without anything getting better, then I'd say your VRV is starting to bleed vac pressure. If there is a time in the next few months that you won't be using your IDI, send me your VRV and I'll inspect it. If it's fixable, I can rebuild it. In a few months, I should have full replacement VRV's in my inventory, once all my suppliers send me my parts.

 

[Cubey]

If your modulator is functioning fine, and your vac pump is ok, and you don't have any vac leaks in your hoses, and you have tried adjusting the VRV on the IP in various rotations without anything getting better, then I'd say your VRV is starting to bleed vac pressure. If there is a time in the next few months that you won't be using your IDI, send me your VRV and I'll inspect it. If it's fixable, I can rebuild it. In a few months, I should have full replacement VRV's in my inventory, once all my suppliers send me my parts.

I could pull the vrv off my f250 (drives fine but now being stored, has no insurance) and swap it out for now. It could be a bad hose though still related to the vrv. That's all that's left that hasn't been touched. I need to find out where it's being routed to from the vrv to steel line someplace.

 

[genscripter]

Definitely check everything else in that vac system first, to make sure the VRV isn't the issue. You might just have a pin hole leak somewhere in the hoses before or after VRV that could be affecting the vac pressure at the modulator.

 

[IDIBRONCO]

If it's fixable, I can rebuild it. In a few months, I should have full replacement VRV's in my inventory, once all my suppliers send me my parts.

That's great. I'm glad that somebody is doing something about this obselete part.

 

[Cubey]

I've done the vac pump, then swapped the f250's vac pump in to be sure, so it has an older vac pump (but good, and has a lifetime warranty with oreilly), vac pump hose, the booster, the booster hose, the MV at the trans, the MV hose. I have only the ac vent, trans and booster connected. 2 other lines are capped off. Cruise and.... i don't know what else.. vac canister maybe? I have the connectors capped off on the distribution block with vinyl caps for those 2.

I found where the vmv hose ends up, right on the back side of the engine. I need to get some more 1/4" hose before I can try changing it.