funny, my wife just said "hey, where did the cork to the wine go?"
So ... a Ferrari owner had a problem which was solved by FChatters, and in a few days the car and owner will get exercised. It doesn't get any better than that, does it? I know I said this already, but FChat and its contributors are an amazing resource!
So I pulled the diverter valve off to test it, and when I tried to blow into the vaccum line coming off the electrovalve into the diverter valve, I couldnt get air passage either blowing or sucking. Then i noticed this f&cking brass wood screw inserted about a 1/2 way into the tube going from the diverter valve to the electrovalve. What part number is this?? Image Unavailable, Please Login
Ok, now that I have the brass screw out of the air tube, I need a little help checking the valve. when I put a suction on tube "A" (either blowing or sucking), little puffs of air come out of "B", which was connected to nothing when I removed the valve. Once the little puff of air is expelled, it holds suction, and I can hear the diaphram moving in and out of the valve. However, when I hold the suction (either blowing or sucking), nothing changes in the flow of air between the large inlet and outlet holes.... I cant imagine this thing taking more vacuum than i can apply with my mouth to make the valve work (no wise ass comments please, or i'll send a brass screw your way). also, the little round "screen looking thing" at the bottom of the valve, i am going to take that off and see what happens.
Yes, a screw directly blocking the vacuum line might prevent the Diverter Valve from working This is normal, "B" is the vent to atmosphere -- so no hose connected there is correct, and air moving in/out of this fitting, as the internal diaphragm/mechanism moves, is expected. The "screen" at the bottom is where the air pump air would be "dumped" out to the atmosphere when the Diverter Valve is activated. Maybe your internals are frozen from ~20 years of disuse, so wouldn't hurt to poke around inside if you can; however, it may be that when the Diverter valve is activated, it doesn't fully block air pump air from going to the check valves, it just opens a big leak to the atmosphere -- just a thought... Have you tried just hooking it all back up (without the extra screw ) and seeing if the backfiring situation is fixed?
Not yet. Looking into the inlet and outlet its pretty gunked up with what looks like carbon soot. Does the bottom baffle come off? The schematic in my WSM (GT4) is a totally different diverter. The bottom of my diverter has a baffle on it, and behind the perforated baffle it looks like there is some steel wool substance (either that or its really frickin junked up in there). the plunger mechanism that looks it raises to let air out i can see through the inlet, and i can get a screwdriver on the bottom flange and it does move, but i have a hard time believing suction from that little blue tube could move that plunger up and down (at least with the resistance I am observing). Does anyone have a spare diverter lying around that isnt on thier car so I can ask a few questions about it?
Can't say as I never tried to get inside mine. The early US 308 with two air pumps (as shown in the 308GT4 WSM) do use a different diverter valve (but it provides the same function). Interesting to note that the vacuum source on the early style pulls the internal diaphragm/mechanism down to divert, while, on your later style, the vacuum source pulls the internal diaphragm/mechanism up to divert. Can't recall that I've ever seen a similar cross-section drawing for the later style. In this (fairly recent) thread, an FChatter reported that he could get a new one from NAPA using the GM part number (at a very reasonable price IMO that would make trying to "fix" your old one a low paying job ): http://ferrarichat.com/forum/showthread.php?t=185563&highlight=7030761
I've noticed that you used a Ravenswood Winery cork. The car will run much better if you go with an Italian wine work.
Actually, you might be surprised just how much vacuum you get from the intake. I bought a cheap, hand-operated vacuum pump to test vacuum parts, and yes, many of them need a lot more than I can do by mouth power. For $20: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92474 Birdman
Thanks Steve, I sent him an email, and he confirmed that GM part worked perfectly. I did soak the DV in WD40 overnight, and it did substantially free up the piston, but i will probably just go with an new one.
I actually started with a 1990 lynch bages cork which disinegrated and made a mess in the tube. So, i thought synthetic would be the way to go
I bought that unit, and it arrrived today. I put the prescribed vacuum on the diverter valve and nothing positive happened. So i am going to buy a new Diverter Valve from Napa: GM Part Number 7030761 Also going to order some check valves: GM part number 111705
While i had the diverter valve off, I figured I would yank the carbs.... There was too much play in the linkages to get them adjusted right, and also the base gaskets were leaking, so I figured I would rebuild them. Take a look at the shot of the base gaskets, its like an orange slimy crud between the base of the carb and the gaskets. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
GM part number 7030761 is no longer available (per the NAPA store I visited). We looked through the parts catalog and found NAPA part 2-721 which looked like it would work. However, NAPA indicated that any part they had of this nature would be min $250. I think I am going to head to a junk yard and see if I can pick one off an old GM.
Took the carbs all a a part, pulled the throttle shaft and am going to replace bearings with new sealed ones. I read quite a few threads on this, and they seemed ok but I decided to pull them anyway, and am glad I did, they seem to be in pretty poor condition. Also, I read threads on lead plugs, and drilled those out as well. Carbs are off to the cleaners!!! Image Unavailable, Please Login Image Unavailable, Please Login
Stopped by the local Porsche race shop (S-Car-Go), and they dipped the carbs in the ultrasonic cleaning machine. Contrary to a lot of reports on the this board, the guy who owned the shop claimed that ultrasonic cleaning does not affect the lead plugs. Since I already drilled them out, I guess it doesnt matter!! I have to go out of the country for two weeks, so reassembly will have to wait... Image Unavailable, Please Login Image Unavailable, Please Login
Back to the Diverter Valve. I determined mine was toast. The original ferrari (part number 111705) is between $350 and $400 at the normal Ferrari US parts shops. I tried Napa, but only found the correct DV for $299. Attached is a list of cars that had the same/similar DV, and i searched about 1/4 of those came back with the same Napa DV. So I gave up on Napa. Not sure how others were able to buy the DV from Napa for $60 as reported in other posts. I was thinking you might be able to use any one-in, one-out DV, but didnt want to chance it (and only a few of them were than much cheaper) I also didnt feel like dumpster diving in the wrecking yard... So I went on Flea-bay, and found DV-44 (which is the Standard Motor Products Crossover #). There was one lister for $199, and another lister for the same DV for about $76. I offered him $40 and he accepted, NOS DV valve for me!! The DV-44 is a plastic unit, unlike the metal of the original. I found another lister that is selling an all metal DV-44 unit for $100. First pic is of the original unit Second pic of the DV-44 I bought new for $40 Third pic is of the DV-44 metal unit Document attached for anyone chasing DV's in the future. It has all the GM vehicles that share a similar DV and all the GM part numbers. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Well back from Brazil and the UK. I recieved my shipment of Remington 12ga shotgun shells full of #2 lead duck shot. I have enough to plug about 40 sets of carbs if anyone needs any #2 lead shot. Its getting hard to find due to the environment foulness of it apparently Tommorow I will start re-staking the plugs, the #2 lead shot looks like a near perfect fit (just a little oversized). I bought a few different sizes of punches and will report back later. Image Unavailable, Please Login Image Unavailable, Please Login
Does anyone have a picture of the weber tool used to re-stake the lead plugs? Looked around for one, but couldnt find one to purchase or a picture of what the tip looks like. I messed around with a few options today, and a flat ended punch mushes too much of the lead out of the hole and results in a messy appearance. After a few experiments, I used a flat headed punch just marginally larger than the carb hole, then drilled out the tip slighly so it would accept about 20% of the lead shot (see pic #1). After two or three gentle whacks with a hammer, you can feel the tip of the punch against the carb metal. One more slight tap, and it shears off the excess lead very nicely (see pic #2), and you are left with a near perfect little dimple in the carb hole (see pic #3). Not sure how they originally got them flat, but this method seems to work. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Carbs are all finished. Since i needed to retorque the rear bank heads, I pull both cam covers off and sent them away for powder coating Image Unavailable, Please Login
I'm just following this thread, but does the diverter valve have to work? I took the vanes out of my air pump and my diverter is de-functionalized. I have an Ansa Exhaust (all else stock) and I get no popping. I'm just wondering if the problem is somewhere else. http://www.ferrarichat.com/forum/showthread.php?p=136346969&highlight=diverter#post136346969
I think the problem with my system was that the airpump was continually pumping air into the engine at "off-load" (throttle lift off, ie, the diverter valve is stuck open). But I am no expert. When i plugged the hose from the airpump, no backfire.
