V6 weber K90 install questions

Started putting the Weber on the XJ today.... boy do those instructions suck. It looks like I need to just figure this all out for myself I guess.
1. What vacumn lines really need to be hooked up? I Figure the EGR and dist advance hooked to the front port (variable vacumn), and the air injection control valve thingy and line that goes to the canisters on the PS fenderwell hooked to manifold vacumn.
2. I know PVC to p/s carb fitting, can I just run the bowl vent directly to the canister? Is there really any functional need now to have vacumn to that canister (the one up front next to the rad on the D/S)?
3. What is the function of that goofy canister control valve thing on the rear part of the valve cover? Is it ok to have it out of the loop of the system entirely?
4. All of the heater, vent, and the disco work off of the p/s tin can canisters or the line going to them don't they?
5. Will I need to up the jet size for the 3.4 or is there enough adjustment?
6. I have no idea what sort of PSI the GM 3.4 conversion electric fuel pump (P/N P/N 6472382) puts out but Weber says to regulate to 3-3.5 PSI can I assume that since the pump was made to work with the rochester it should be ok with the weber?

All of this would have been easier if things were hooked up and intact when I started, but the PO had things already screwed up pretty good before hand.
Thanks,
Mike B.
Specs: 86 XJ, 3.4 swapped in using the 2.8 intake and accesories (PO), AX5, 207, disco front. No cruise, no A/C till I get around to reinstalling it.

Its been along time since I messed with my 2.8 so bear with me.

I would say that if you want to keep everything functional hook up all the vacuum lines. There are several you can omit if you are no longer using the factory air cleaner housing though; they should be self evident.

The canisters are your vacuum reserve so yes you do need them.

Bowl vent to charcoal canister, yes keep it, it will not only help pollute our air less by catching unburnt hydrocarbons, but will give you a little better fuel economy, at least theoretically.

The Webers are extremely tunable, as such you may not need to rejet. Only testing will let you know for sure. Did you get the 38/38 DGAS?

As far as your fuel pump, dont assume anything, call GM Goodwrench or look on the web to be sure, if no one else can give you an accurate answer.

Goodluck

XJguy

btt... Got it running but idle is still a bit rough, and get occasional light backfire right off idle... any ideas?
Mike B.

If Im not mistaken, the instructiuons tell you how to make some adjustements. Make sure your timing is right as well. If all else fail, contact Redline Weber by phone, they are very helpful.

XJguy

Hmmm... was hoping someone that had this kit installed would chime in, or at least someone like Eagle would let me know if I had the right type vacumn to the right things.
I got it over to my new garage and tinkered a little.... found what might be part of the problem. When I took it in for inspection I told them to go ahead and install the plugs ect.. I had for a tune up while they had it in there, well it looks like they got it mostly done cept they forgot to tighten the dist. hold down... Grrrr I spent over an hr trying to set the carb and couldn't figure why I was still getting the backfire. Timming light is still in the old garage, hopefully that was the whole problem.... was starting to think it was EGR (looks like a fairly new one) or wrong Vac to the Air injection valve.
ONE BIG ITEM FOR FUTURE REFERENCE..... THE K90 KIT HAS AN ADAPTER ON TOP TO REUSE THE FACTORY AIR CLEANER...... IT IS TALLER THAN THE ROCHESTER AND WHEN YOU SLAM THE HOOD IT WILL PUT A NICE BIG DIMPLE IN THE HOOD.
Mike B.

XJguy said:

If Im not mistaken, the instructiuons tell you how to make some adjustements. Make sure your timing is right as well. If all else fail, contact Redline Weber by phone, they are very helpful.

XJguy

Click to expand...

Yeah did that, I've had Weber carbs before, It's just always in the past been my habit to chuck all air pumps & junk.... (The 84 trooper ran much cleaner with the weber & calmini header than with the E equip and stock carb intact and working correctly) but this 86 has the biggest ClusterFk of hoses and wires I have had to deal with and wanted to keep at least the basics like the air injection just in case the 1 in 100 chance they pop the hood at the emmisions test. You'll see in my other post that hopefully it is a timing issue.
Thanks,
Mike B.

Anyone??? Seems to run decent with timing set right... but still has slight miss at lower rpm's. Any thoughts? Gonna check to make sure plugs were gapped right, and maybe new plug wires.
Mike B.

Check your idle and make sure you have no vacuum leaks.

XJguy

Plug wire #4 & #6 were swapped.... had guy who was doing inspection do cap rotor and plugs and he just put them on the same as the DSPO had them, the wrong way.... runs much better now. Still not as smooth at idle as I thought it should be (didn't pull and check plugs for proper gap yet though) but it idles as smooth as the 225 in my CJ but that's an oddfire.
The GM 3.4 conversion elec. pump was putting out 5 psi, put a regulator and gauge on and backed it off to 3 psi and was able to dial the carb in much better.
Am I expecting the 3.4 to run smoother than is possible maybe? Since it was originaly made to be in the Camaros and fuel injected maybe it has a fairly lumpy cam? It sure does make the XJ scoot more than I ever expected out of a 60* chevy V6.
Mike B.