Should I go back to a stock intake?

Don't hurt your back installing that intake -call "Chuck" and let him do it. Mike D.

 

116 cam

Dave. Did you put the cam in stright up or degree it. I asked that question when i baught the cam and Tony from postons said put it in stright up.Also I shift my car between 5 and 55 hundred and I put two gaskes under the carb. Well the only thing i can say is try the stock one again. As you know for every 100 lbs. off the car It's 1/10 of a second quicker.

Tony

 

Tony

Well I have to admit that I've never degreed a cam, probably why most of my cars have run OK and a couple have run exceptionaly well. I did have a three keyway timing set and set it up in all three positions, straight up ran the best although I don't really know what straight up was. If I do install the stock intake I'm going to use a cherry picker, I don't know anyone named Chuck!

Dave B

 

Since we're confessing to stuff here,
What intake gaskets am I "supposed" to be using? All I have is the valley pan gasket that came with the stock intake. I did block off the heat passages though.

 

That's the only intake gasket that I've ever used, not much of an endorsment really, and don't feel that it's ever been a problem. As far as the confessing, lets stop before we gwt to the personal stuff. :laugh:

Dave B

 

Intake Gasket

Mark. I used the stock pan gasket also on my poston intake but, i did not block off the heate passages and, i did not grind the center plentum at all like the others have. I guess it's what ever you prefer.

Tony :3gears: :beer

 

Well I bit the bullet today and removed the Poston and installed the stock cast manifold. Apparently besides the wieght the only real difference between the two is the color. It still acts like it's got a vaccum leak, you know hold your hand over the carb and it speeds up, until it's compleatly warmed up then it seems to run OK. Even when it's warmed up it will still speed up slightly when you restrict the airflow a little. Oh well it'll be as good as new when I fab a throttle bracket.

Dave B

 

I have re-insatlled stock intakes alone many times. You just have to do it fast and have good aim! Then deal with a sore back for about three days if you are lucky! Watch out for Hernias as well!

 

Back will be better in only three days huh, that's good news. Toting it up from the basement was the hard part. I ended up laying it accross the valve covers at a right angle to the engine, then just got as far in there as I could, lifted it and turned, went right in. That wasn't so bad but this vaccum/idle problem is driving me crazy. Maybe my real problem is that I'm doing most of my checks before the engine is fully warmed up. There is no choke hooked up, when first started it will not idle alone. After a couple of minutes it will idle on its own but it will chug like it's about to die for three or four seconds. Then it will speed up and sound nearly normal for about the same amount of time, and back and fourth etc. Finally when it is completely warmed up it runs pretty good but will still pick up slight on the idle if you restrict the carb opening a little. I'm wondering if my idle circuit needs to be enlarged slightly. How about vaccum leak around the valve guides?? The reason I wonder about the idle circuit is for a while I had a borrowed Holley 850 DP on the car and didn't have any idle problems, it would idle on its own right from startup. It also ran very,very good but had a tendency to bog on a full throttle takeoff. Does the Holley have a bigger idle circuit than the Q-Jet, oh yeah the car has a Straightline cam in it, 226/238 I think. Any ideas, Im stumped..

Dave B o No:

 

Hey Dave, what year of q-jet do you have on there? Maybe it's 350 carb?

I've been having the same startup issues you have but every time I make another adjustment on the choke it gets a little better.

 

It's a 7042240 out of a 72 with a 455, although it has a main body from a 7043240. The main bodies are the same for both years so that's not a problem. I'm sure the carb is in good shape, just wonder about the idle circuit moving enough fuel.

Dave B

 

I dunno, maybe the missing choke is the issue. When cold, it makes the a/f mixture richer.

 

Dave
I'd say you have proven that it is a carb issue, if the intake change didn't help, and you said it ran good with the Holley. Can you get any response hunting for vacuum leaks spraying carb cleaner/other flamables around the carb base, etc?
I went through months of hunting the same kind of mystery vacuum leak. Carb change solved it. Could be that your throttle plate is warped. I had Home Depot cut me a piece of glass the right size and checked all my throttle plates for flatness. None were completely flat,and some were hugely warped!! By the way, I had the thick base gasket with the plastic inserts around the bolt holes, but JO made me toss it and use two thin gaskets.

 

Bout ready to sell this Buick and get me another Mopar, never had this much trouble with one of them. My old buddys have been trying to get me back in the fold for years. You recon a 440 would fit in a Buick?? Seriously I just drove the car and it won't idle the same speed two times in a row. Some times 850 RPMs some times drops to 600 RPMs some times even tries to die, have to give it a squirt of gas. When I got home sat in the driveway and in neutral it idles 1100 RPMs, put it in drive it goes to 800/900 RPMs, back to neutral 1100 RPMs to reverse 800/900 RPMs. Then back to neutral 1100 RPMs then to reverse 600 RPMs then slowly climbs to 800/900 RPMs. Some times when you put it in gear or come to a stop the idle is OK then the next time it's crappy even wanting to die. Also I noticed today that it's running 15 degrees hotter than it normally does, sounds lean doesn't it? Carb has been redone twice by guys that really know thier stuff, unlike me. Now I'm a tinker and change stuff around a lot trying different stuff, so the carb has probably been on and off the car ten times since I last got it. Who knows maybe I leaned on the bolts to hard. Sold a hood to finance the work on my Stage 1 heads, might have to buy a carb instead. :af: ou:

Dave B

 

Carb

Dave. You can only rebuild a carb so many times then you have to toss it. Sounds to me like you need a new one. and you need to make sure you have no vacum leaks. Try spraying the outside of the carb where they bolt together and the intake around the base and the heads.


Tony :3gears: :beer

 

Well I was hoping to get by spending less than $500 on improvements on the car this summer, not counting entry fees. A new carb is going to eat all that up. ou: The guy that loaned me the 850 DP had me take it off to sell at a swapmeet, I didn't even ask what he wanted for it. $100 ou: ou: ou:
Almost forgot, I've sprayed enough WD 40 around that engine they'll probably send me a Christmas card this year.

Dave B

 

Man Dave, sorry to hear you're having such a bad time.
It's starting to sound like maybe the carb got torqued down too hard and maybe the air horn got warped. I wish I had another q-jet to send you to try.

 

Hey man thanks for the concern, I'm like them guys on Hee Haw, if it weren't for bad luck I'd have no luck at all. What's weird is I have a 7042240/800 CFM Q-Jet in my basement already boxed up and sold. Course I also have two 800 Thermo Quads, and two 850 T-Quads in the basement. Think I'll fix one up and make a swap here. Got nothing to lose. o No: I used to run the one 850 T-Quad, in fact the car ran better WOT with that carb than it ever did with a Q-Jet. Only reason I changed it was a vaccum leak, very sloppy primary throttle shaft bushings.

Dave B

 

Can't let this thread die, installed my 850 T-Quad today, idle problem solved. Course now I have different problems. The car is hard to start, harder than the Q-Jet, but once warmed up starts just fine. Idles at 850 RPMs in neutral and drops to 800 RPMs in gear. Odd that the Q-Jet would drop 350 RPMs when put into gear. It's pulling 13 inches of vaccum while the Q/J was pulling 15. The throttle jets seem to have no effect on vaccum but if you do the hand over the carb trick it doesn't speed up like when it has a vaccum leak. If you put your hand over the carb it dies instantly, like it's supposed to. Now I'm wondering if it's running rich, I set the floats according to info I got at a T-Quad site but they're higher than the book calls for. If it's rich will that cause my start problems that go away when it's warmed up, and will it cause my problem with the idle screws?? ou:

Dave B

 

Alright, one more question.
I still have the intake on the car and everything is working pretty good. The only thing that has me concerned is there is a small puddle of oil sitting on top of the timing chain cover. It's in the dip right behind the dist. Also, there are some oil dropplets near the front of the intake manifold just in front of the carb. It looks like they were blew up there by the fan or something. There is no oil on the ground and the rest of the motor looks dry.

Is it possible I just didn't get the front of the intake sealed properly? I used RTV on the front and back and around the water holes. Maybe not enough on the front???