I wanted to start this thread to give my experience with the jet 35002 stage 2 Qjet.

I picked mine up used on eBay for a substantial savings. Used as in used once/bolted on in eBay terms. It looked brand new and didn't even smell of gas when I received it. I had to swap intakes as mine wasn't dual patterned. I went from one Stealth to another. Everything bolted up as it should have, though I had to remove my BTO throttle and TV bracket because it is bored for Edelbrock throttle blades and spacing. I fortunately had a TCI bracket on hand that bolted onto the rear ARP carb studs and I was back in business.

Initially it wouldn't start because I buggered the dizzy when I stabbed it the first 5 times. It's still not right, but it's running. With no adjustments made to the carb, it fired right off. Idle was low and I adjusted that today. Idles solid, revs good, but I still have some ignition issues to chase down with some intermittent backfire in the exhaust. The 90 feet I drove it felt amazingly smoother and torquey than the Edelbrock ever did, even with ignition issues.

I plan on messing with it in another couple weeks as time and weather allows, hopefully get the dizzy done correctly and figure out any other ignition related issues I caused.

I did contact Jet about 2 questions- I had a loose vacuum port and wanted a vacuum port diagram or recommendation. I contacted them via email through the website. The next day I received a response saying he didn't know anything about carburetors and to call them and ask for the carb department. I called and spoke to Johnny at extension 106 I believe. He sad with the port that was loose to tap it back in. When asked about a vacuum diagram, he said they don't provide those.

That brings me to the questions for you fellas- does it appear that I have everything connected to the proper vacuum ports? I pulled up the diagram on here for a non emissions Canadian model and copied it the best I could. Brake booster rear, PCV front, and vacuum advance can to front.

 

Nice find - brand new.
Here is what I came up with for my QJet carb:

 

Awesome- thanks! I'm moving the vac advance from the front to the rear seeing this. Cleaner appearance and no hoping I ID'd and connected to the correct port up front.

 

Quick update. Had some time to jack around with it yesterday. Set the fast idle and moved the vac advance line. I had to buy a double D driver at Oh, Oh, Oh, O'Reilly's to adjust the idle screws. I *thought* jet advertised them as slotted. Murphy's law gets me new tools. It starts easier than the Edelbrock, and fast idle ROCKS! For the first time EVER (since I've owned the car since 2003ish), I started her cold and walked away. No babysitting, pumping the accelerator to keep her running, NADA. Instant 1500 rpm!

Tried to adjust with my vacuum gauge to get rid of the backfire. Best I could do was make it slightly better and waay worse. Drove down the block and back a couple times. At idle and WOT she hauled *** the first run, was off the 2nd. Part throttle was barely drivable- down on power and herky jerky accompanied by lots of backfires in the exhaust. Messed with the timing and figured out I have 1 coil screw stripped on my cap. Also had a plug wire resting on the #1 primary. I'm going to order a new cap and rotor kit and new wires, and reclock my distributor correctly. Where I think it needs to be won't allow the L69 air cleaner to seat correctly.

 

Are your plug wire boots at the distributor cap end right up against the air cleaner? Mine were and would arc out in moist air conditions.
You can convert to a small body distributor and separate coil.
There was just a post here about doing just that: https://www.thirdgen.org/forums/elec...utor-swap.html

 

If it doesn't work out, I may resort to that. The distributor I have now is an Accel Blueprint/HEI supercoil with less than 500 miles- I don't want to scrap it yet.

I figure this setup is as close to stock "geometry" as I've had so it *shouldn't* be an issue as it wasn't before even with the OG butchered e4me. Also, the main issue I have is the wire connectors for 12v, tach, etc all point at the water pump pulley creating the air cleaner clearance issue where before they pointed at the driver's fender.

Wires are Taylor Thundervolt 40s. Never had an issue with them, but I wouldn't be surprised if there's some arcing as you brought up with all the new clearance issues. I noticed I was getting what I thought was static shocked more than usual when I'd touch things under the hood.

 

You can rotate the distributor to anywhere you want, as long as the rotor follows the housing (and cap).
Also, you can put #1 in any position you desire.
So what you are saying is that you need to rotate the whole thing 90 degrees CCW? Or just the cap?
If your cap has those L-shaped spring-loaded hold-downs, then it can attach to the distributor base in any of 4 positions.
Is the vacuum advance canister pointing somewhere between #6 and #8?
If so, then all you need to do is move the cap 90 degrees and reposition your plug wires on the cap.

 

Wut?





Are there GM HEIs out there that don't have the alignment peg so that the cap can only go on one way?

If the hookups on the cap don't point toward the driver's fender, you need to drop the distributor in right. If you get it too far off the vac advance will hit the intake before the timing is right, or other goofyness.

The stock aircleaner should have a sizeable dent in the back to clear the distributor. If it doesn't clear it's assembled wrong.

Pull the #1 plug. Put a finger in the hole. Roll the engine over until you feel air rushing out. Watch the timing indicator, run it up until the balancer and timing tab read 0*, you should be at TDC. Drop the distributor with the rotor pointing at #1 (approx driver's headlight). If it won't drop in, use a large screwdriver to turn the oil drive and try again. It doesnt matter as much with a carb, but it still fits better in the car when it's all right.

 

Thanks Drew - guess I got confused. I forgot about the notch.
In any case, this is what his should look like with the proper orientation..

 

Exactly. Did the above a couple times but bumped the starter to get it to drop on the oil pump shaft. Last couple time times I pulled a VC and went by rocker arms on #1/6. It ended up clocked wrong each time so going to the screwdriver or oil pump primer next go round. I was obviously off a few teeth when I started it each time.

With the Stealth intake, an L screw will hit a runner in certain positions, usually just before the advance can hitting the firewall the way it's currently positioned.

Appreciate all the help from you both. Just need to schedule more time and take my time the next opportunity I have.

 

Put in a new cap and rotor today along with new wires. Repositioned the oil pump drive shaft then and got everything lined up the right way. Popped off easier and right away, but I still have the backfire in the exhaust. Still feels down on power since you feel it popping. Need to get a video- it's at steady state and just as rpms come down that it happens.

I did find a piece of metal under the valve cover- thought it could be trash that fell in and I didn't catch when I did the intake. It looked to have fornicated and lost with a spring at some point.

Lastly, had 1 coil screw break off in the old cap so I'm running 3 of 4 until I get one tomorrow.

 

Here's the piece I found. Looks almost like a pull tab from a can of BG Oil additive I used when not using Rotella.

 

Looks like it might be a retainer from a valve seal. Like these:

 

Didn't even think about that. Probably correct. I put Felpro Blues on about 10 years ago. Should be fine you think?

 

If the tension ring came off a valve seal, the seal probably isn't staying on the valve guide. If the seal is free, you'll probably get oil in the cylinder.

 

Thanks. Guess I'll add that to the list after I get the backfire sorted.

 

Replaced the coil with a new Accel Supercoil. Made no difference. Then replaced the ICU in the distributor with a known good unit from my spare dizzy, and double checked the internal ground. No change.

Discovered my timing light is junk. According to it I had 80* at idle, and the more I advanced it (cw?) It got closer to the actual numbers on the balancer.

 

Turn the distributor Counter-clockwise to advance it. You were retarding it, that's why the line came back towards the numbers.

Did it backfire before the carb change???

 

Ok, that makes sense. In that case, the more I advanced it the more it backfired and tried to die.

Never had any issues before the carb and intake. Intake is the same as what it replaced besides carb mounting bolts holes.

 

Post pictures.

 

https://photos.app.goo.gl/tuub5tp63cMEgXC66

Video of what it's doing from in the car.

What specifically do you want photos of? I'll get whatever I can.

 

Sounds just like a flat cam lobe would sound. Check your plug wires and make sure you don't have any switched like 5-7 or 8-4... Did it run smoother with the other setup?

 

I'll double check those.

Ran and reved much smoother. Would pull hard, just wasn't consistent with wot runs and cold starts were awful with the Edelbrock. Happened immediately after swapping carb and intake.

 

Also cam is 214/224 with .442/465 at .050, and I'm running 1.6 roller rockers.

 

OK, so you are NOW running the Weiand 8004 intake with the Quadrajet, correct?
Your cam should pull at least 15" of idle vacuum. Have you measured yours yet? Is the needle stable?
I watched the video. That helped and I agree with BIRD91ZRAG - Sounds just like a flat cam lobe would sound. Check your plug wires and make sure you don't have any switched like 5-7 or 8-4...


Here is a trick I learned on a older episode of Garage Squad.
Use an old-school 12v test light - ground the alligator clip end. Poke through the plug wire boots at the distributor one-by-one, looking for the cylinder that does NOT make a difference when probed. The one that doesn't points to your problem cylinder.

 

Correct. Running the 8004 now. Same intake with dual carb bolt pattern and different part number.

IIRC, when I was setting idle I was pulling about 14inches, but was anything but stable. It was dipping down to 11. I'll try and get a video of that as well.

I checked the order again. I was off by 1 all the way around. I had 1 starting right next to the wiring for the coil. Moved them all with the same result. I did each wire individually and labeled them at the distributor boot. I'll double check termination points when I get some time this weekend and will probe them as well.

When I moved them, it ran about the same to worse, but I ran out of advance adjustment as the vac can on the dizzy was hitting the intake. I'll probably have to reset since I set it up with TDC and the rotor pointing to what is now #2.

 

Easy to do. You don't have to pull the distributor completely out. Since the rotation is clockwise, you just need to pull the distributor base up enough to disengage the drive gears. With the cap off, move the rotor what amounts to one tooth clockwise from where it was when it disengaged, and then try to put the distributor back down. It may take a few tries, but each time the oil pump driveshaft will move slightly. About the fourth try, it should drop into place. DONE. Hopefully, you only moved it 1 tooth.

 

You don't happen to try to adjust the rocker arms while you were in the intake swap, did you?

 

Going to give it a shot soon- home schooling, home officing, and the honey do/done list keep getting in the way.

1 tooth is all? I've purposely left my STB disco'd for how many times I've had the distributor out- there's enough clearance to account for the engine rocking with the supercoil installed, if that. Hoping this will be the last.

Is it possible that the intake gasket is leaking between cylinders? I installed dry except for the china wall/ends. Normally I smear an ultra thin layer of the same RTV around all head and intake ports as a precaution.

 

Didn't touch them.

 

That eliminates that possibility.

Another thing I just thought of, I wonder if there's a small chunk of old intake gasket stuck holding a valve open just a touch. That would explain the popping and roughness I see at idle..

Usually if an intake gasket doesn't seal up, you get an oil leak that smokes and fouls out plugs as it allows oil to be sucked in out of the lifter galley.

 

13 teeth
The distributor gear has 13 teeth, so each tooth change moves the whole distributor about 28 degrees.

Because it's only 1 tooth you need to move it (in the direction of rotation), you are going to use that rotation that happens as you try to put the housing back down to turn the oil pump drive shaft for you. Each time you try to set it down, it will rotate the shaft slightly. About the 4th try, it will drop all the way in.

 

Messed with it some more yesterday finally. When it was running I sprayed carb cleaner along the intake ends,c and it died. Also, my fan blew a fuse so as it got hot backfiring got better. I also found it was backfiring through carb too.

Needless to say, I am pretty sure it is the intake gasket, the intake is warped, or both. I think I will try fell pro 1205 and see if that fixes a problem along with some RTV around all ports.

 

Stock port size would be the Felpro 1256. If you need a thicker (stock type) gasket, use their MS 90314-2.

 

That's the one I used in the installation originally. Heads are mildly ported.

 

Changed the gasket out. I used "The Right Stuff" on the china walls and a thin layer around all ports on both heads and intake, which wasn't warped. I snugged it down to 12-15ft lbs, waited about 90 minutes, and finished torquing to 30 lbs.

It's about 50% better. Still backfiring, and no guts under load.

I sprayed brake cleaner around the intake and carb gaskets with no change. I'm using the 4 hole insulated/thick carb gasket. Could this be an issue as well?

 

Does the Qjet have a screw cap just in front of the air horn on top. Should be an adjustable partial throttle screw under it to dial in off throttle response. Also rear flap can be adjusted.. not sure if it's related to your problem, but??

 

There should be a picture attached of a top view of the car. Nothing stood out in particular like what you were asking about.

In the 30 second drive from pulling it back up into the driveway this morning I got the headers hot enough and dumped water on each primary. One, two, and eight, did not sizzle and barely evaporated the water off.

 

I have been messing with distributor again. I may try a spare to eliminate the "guts" of it. This is how it ended after moving the rotor 1 tooth CCW in an effort to diagnose. Confirmed #1 at TDC with a pick. All rockers move well and are aligned. None show less lift than others visually to suggest pushrods or can lobes.

Something's messing with 2,1,8.

 

Post #22 mentions a flat cam from after seeing your video.
With 3 cylinders not operating correctly, I'm leaning that way also.
Here is what can happen to a camshaft in only 20 minutes if EVERYTHING is not correct.








Drain your oil and strain it through a paper towel or fine rag. Look for specs. They really show up with the flash from a camera. Inspect the oil filter also. Cut it open and spread the pleats out.

 

You see how you have your plug wires twisted together like a pile of spaghetti?
Have you EVER seen ANY engine in any car like that? It's not done. Why? Because it's WRONG.
The wires need to be separated - otherwise the spark can jump from one wire to another. Especially in humid or rainy weather.

I see rotators on the exhaust valves. This suggests that your heads will not allow enough valve lift for the camshaft you are using.

On the plus side, it looks like you have the distributor installed correctly now.

See how important pictures are?

 

Finally had some time to dig back in and get this solved, and wanted to update should it help anybody else.

I had leaking intake gaskets paired with fouled plugs. When I replaced the plugs I *thought* they should still be good, not realizing how fast they'd foul out. That paired with leaking intake gaskets and a choke wire that wasn't connected made the car run like crap.

Final fix was ARP intake bolts, felpro gaskets with gasgacinch on the head side, and Accel shorty header plugs. Timing set at 14* initial and it runs better than ever. Now on to replace the weather checked tires so I can actually safely drive it and dial in adjustable vacuum advance.

 

Thought I'd update a couple years later. Finally got some tires on the car as she's basically sat the last couple years. I would really like to drive it farther than around my neighborhood.

Was still fouling out plugs. Throttle blades were above transfer slots at idle. Had absolutely no control or difference in idle speed and vacuum with the mixture screws.

Pulled the lid and found out idle air bypass was blocked off with lead. Pulled the lead plugs out, and got some control at the mix screws being almost turned in all the way. Ordered a jet assortment. Going down to a 70 from current 74 with 50M rods in hopes it will give me some more control.

I still need to tighten the secondaries maybe an eighth of a turn, but otherwise acceleration is unbelievable for a little cammed 305 with long tubes. Looking forward to see how it does on the interstate and what kind of fuel economy I can squeak out of her as well. I will say it punches like fuel injection.

 

1 more update. Still getting it to 100% dialed in, but getting close- probably at 90-95%. I have a slight lean tip in from no throttle to light throttle I'm working out with the APT. I think I'm at the point that perfect is about 1/8-1/4 turn away. Drove the car to work for first time today. We'll see how she does for mpg, but wow are stoplights, on and off ramps soooo much more fun than my usual drivers.

I would strongly advise buying Cliff Ruggle's book (and numbered drill bits, pen vise) if you purchase a Jet Quadrajet, or any other rebuilt or core for that matter. Cliff stated on his website that "Jet is no different than the other 'rebuilders' out there, but they have better coloring and zinc work". I've learned more the last couple months working on this carb he was right, and I've learned more than I thought I ever would. There's people that know waaay more than me, but I don't feel like I'm repeating internet and hotrodder lore/misunderstandings when I discuss, diagnose or modify the carb. If you know enough to be dangerous like me, the cost of tuition is time, a book, some tools and dedication.

 

JET was once decent, but their main product guy left and created S.M.I. going off memory. I only like to build virgin unmodified cores myself.

I know Cliff Ruggles is not a fan but I like to add Primary Pull over enrichment for engines that run mainly on the street. Can run it leaner for economy and still get the necessary fuel. All 75+ Q-Jets are cast for them but not many are drilled for them. Its a 3rd set of brass tubes.

As for your lean off-idle transition. You did burnish the accelerator pump check ball seat and verified that fuel flows as soon as the throttle moves?

 

Never knew that. Makes sense. Some, maybe a LOT, of my knowledge and perception of companies is still from 90's and early 2000's since having kids and careers, and doesn't always do me favors. Amazing how many changes in ownership, and quality, there's been in the last 20+ years being out of the know.

I did burnish the checkball when I was checking everything over as well as verified fuel as soon as the throttle moves. I have a new accelerator pump assembly coming from Cliffs. After breaking a secondary rod, air valve spring, and finding a broken (snipped?) APT spring in the carb, I just ordered a slew of parts so I'll know it's all good parts and not cheap crap.

I did add another turn to the vacuum advance last night to see if maybe she wants a bit more timing and faster at that transition, but haven't had a chance to take it out and test.

Just looked into pullover enrichment. If I'm understanding it right, it supplements from the idle circuit like a mini accelerator pump shot. I only have the 2 pairs of tubes on the airhorn. To add it in, I'd have to add an additional set? What about drilling the air horn- is there a dimple or casting mark for drilling, and what size to start? I'll have to check out my airhorn more closely when I get home.



Mentioning kids earlier- my oldest daughter (13) came out and asked what I was doing. I made a comment about tuning the carb. She then says, "Wait- you don't just plug your laptop into it and tune it like you do mom's truck and your trucks?". I had to laugh, and explain how HPTuners is the "new" way of doing what I was doing with the carb, or adjust timing with the distributor. If I could only talk her into a square body for her first 'car'.

 

Primary POE is more or less all there, there is a little drilling needed. I would have to pull the old casting out with my pin drills to tell you what size I them out. They are basically like the secondary POE. They help get fuel flowing before the main metering take over but continue to contribute as long as your foot is down. I have noticed them on several marine carbs where the added throttle response helps get a boat especially when towing a skier up on plane more smoothly.

How are your transition slots? If you do not have enough bypass air for your setup, the throttle plates will be open too far. That leads to mixture screws having less effect as it skews the idle vs off-idle transition. When there is enough bypass air the throttle is more closed covering more of the transition slots. This means less fuel from the transition slots and more needed from the idle screws. That allows the transition slots to add fuel as you come up off idle rather than supplying alot of the idle fuel. Going off memory I want to say my metric idle mixture screws are 6.5 turns out. When you lightly twisted the throttle my engine leaped in response.

This was a carb I had setup for a 305 more than 10 years earlier, it had been sitting on the shelf in the shop 3-4 years after being on my 80 Vette for a while then on an ElCamino for 4-5 years. The accelerator pump was near dead as it took 5-6 good solid pumps to squirt enough fuel into the manifold to get it to cold start and it was pretty dirty inside. Still had good response. Under slight throttle angle movements the accelerator pump plays a small role, its need to a certain extent but other things have to happen as well. The popping when I let off is an exhaist air leak where the mufflers were clamped to the collectors causing the rich mixture to combust in the mufflers.

 

My transition slots are almost as uncovered as they can get- the throttle blades were physically completely closed at idle. I did add about 1 turn on the idle speed screw the other day, so they're now just above physically closed/minimum amount of transition slot exposed. I had to add a boatload of idle air bypass to gain any kind of control over the mixture screws. I opened up idle air bypass initially to .070, and then .010 at a time to .113. It was still 'fat' at idle, and then I discovered that the secondary rod where it hangs from the hanger had broke. I 'fixed' it (until new rods come in), and was able to gain some control over the mixture screws. I currently have them 3 turns out. I also resized my idle tubes to .033 (was .040 prior), and idle air bleeds are opened up to .070. I did enlarge the IDCR initially, tried to pull to resize back down to 'stock', but the drywall screw trick just didn't work for removal.

That engine sounds and revs nice! If I punch mine fast it revs like that with no delay, bog. What's killing me is the "barely more than weight of my foot" on the accelerator pedal to "just a little pressure to maintain speed" pressure. You can feel and hear the lean bog before the system catches up over maybe .5-1 seconds.

 

Drywall screw trick works for me. But I have a mini torch that I use to heat it for a bit first. Het it, put a little penetrating PB Blaster on it while warm, then heat it again. Doesn't take a ton of heat. Maybe 20-30 seconds a tube but it can take 3-4 applications of heat and penetrate and an overnight soak of penetrate for it to want to break free.

 

The idle tubes popped right out with the screw trick- no heat or penetrating oil required. Problem with the IDCR is they're deep enough in the bore the drywall screw bites the carburetor bore instead of/before the ICDR.

Received my order from Cliffs today- everything but idle tubes which are on backorder. Hopefully get after it tomorrow night.

The way it sits now, I think I have just another 1/4-3/4 turn on the APT to get it perfect. I'll wait until I get the new 'custom' 50M rods in and see what difference they make.