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By Ryan New Mexico - 10 Years Ago
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Hey Guys,
Round five with this engine. The motor starts great, idles great and revs great. I have a 3x2 edel 553 intake with Ford 94's set up with progressive link. Like I said it will sit and idle all day and I can rev the motor and bring in the two secondary carbs without an issue. I went through and checked valve lash again and is set at .015.
Once I put the car in gear to drive, it sputters and pukes or dies. If I can get it to run I have to feather the pedal to get it up to 20-30 mph then it seems ok. When the car is in neutral and on jack stands the drive line rotates freely with no drag or binding. It is just under load the motor does this. What is the deal with this thing??????? Trans is a TH350, 2000 Stall, 57' (later) distributor with Pertronix 2 setup.
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By miker - 10 Years Ago
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I assume you have a 57-later dizzy. What's the initial timing, is the vacumn advance hooked up, if so where.
Jet sizes in carb, and how far out are the idle screws.
It's been years since I ran the 94 tri power set up, but many here do, and with more info I'm sure someone can help out.
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By Ryan New Mexico - 10 Years Ago
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Hey Miker,
Yea it is a 57 later dist. I do have the vacuum hooked up, I have a T coming off of the intake, one to the distributor, the other to the trans (TH350). I am not sure on the idle screws, I tuned them with a vacuum gage to pull max vacuum (15 lbs). I will get timing and Jets tonight when I get home.
Thanks
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By snowcone - 10 Years Ago
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I have no experience with tri carby set up so this might not be relevant, but the normal vacuum pick up point for a distributor should be from a port on the carby above the butterflies.
If you are picking it up from the manifold then you will have full vacuum all the time. I just encountered the exact same thing with my 64 T Bird with a 390.
The previous owner had set the timing up at 12 BTDC with the vacuum hose connected but the distributor was getting vacuum from the manifold.
The car was difficult to get off the mark without backfiring and coughing, but it ran OK once on the move.
When I checked the timing with the vacuum line connected it was 12 BTDC but with it disconnected the timing was very much retarded.
I set it to 12 BTDC with the vacuum hose blocked and then reconnected it to a port on the carby above the butterflies and after this the hesitation was gone and it was flying.
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By lowrider - 10 Years Ago
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Need a little more info. Did you block off the power valves & close off the idle circuits in the secondary carbs? Most problems with these is the secondary carb throttle plates are not sealing good enough at idle and it creates a vacuum leak. Cover the secondary carbs with your hand while it's running you'll see what I mean. Im running the same setup in my 57. Took me awhile to dial it in but runs great now.
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By charliemccraney - 10 Years Ago
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Operating the vacuum advance with manifold vacuum should not be a problem. It requires a bit different tune, idle speed adjustment and maybe idle mixture adjustment, than the other way but should work fine. Regardless, that's an easy theory to test. Disconnect and plug it. Does the problem go away, change, or stay the same?
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By Ryan New Mexico - 10 Years Ago
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Hey Dan,
Yes sir, the secondary carbs do not have mixture screws or power valves, they are set up strictly as secondary on a progressive link. All the stumbling takes place at the 10-20 mph range, secondary's do not even get open before I start cussing, haha.. I have placed my hands over the secondary carbs while idling and I notice a very slight vacuum, but it has very little effect to the motor, so I think they are sealed somewhat well.
I am going to go back tonight and check all of the plugs. Probably should have done that already, but we shall see.
What distributor are you running?
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By Riz - 10 Years Ago
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I have the 3x2 set up sounds similar to yours also a TH350 But running a Mallory dizzy with mech advance so no vacuum. Had some stumble off idle once and was PCV related. The 94s are notoriously twitchy and react poorly to fuel pressure (mine will flood at anything more than 2.5 psi. Might be fuel related or I once had a vac modulator on the trans go bad immediate out of the box failure--it was pulling ATF into the engine. And short shifting or missing 2nd and jumping to 3rd.I might try to isolate all the vacuum sources. I have a spare port on my manifold that I ran a vac gage through the firewall and watched it while driving. When the trans was at highest load (1-2 shift) the gauge freaked out.
Not sure if I'm explaining that this makes sense LMK if it doesn't
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By lowrider - 10 Years Ago
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Ryan, thanks for the info. The problem I had with my 3X2 was getting a low enough idle speed. It didn't want to idle below 800 rpm's, didn't accelerate right and would flood after shutdown when hot. I tried a half dozen carb bases & throttle plates (even the 7* plates). I finally picked up 2 new secondary carb bases from Vintage Speed. That cured the idle problem & acceleration concern. The flooding I installed 1/2in. spacers under the carbs & a fuel pressure regulator set to 2 1/2lbs. Runs like it should now.
Next question is what size power valve are you running. At 15in. vacuum you should run a number 7 1/2 ( half the manifold vacuum). Maybe the one your running is opening too fast or slow to run correctly. What model number 94 carbs are you running? Secondary's should at least be the same model number.
I converted my ignition system to a Ford Duraspark system and run it with mechanical advance only, timing set at 16* (running a good size cam) with total advance at 38* if I recall correctly. Before that I ran an aftermarket dual point with the vacuum advance hooked up to the center carb after I did Teds modification to do so. Ran good with both systems but I prefer the Duraspark system for its convenience.
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By Ryan New Mexico - 10 Years Ago
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Hey Dan,
Thanks for the info. I do run a Holley Fuel regulator and it is set right at 2 lbs, so I think I am good there. You bring up a great point with the power valve, it is a 4.5. I will call vintage speed and get a 7.5, to see if that helps. The duraspark distributor you are talking about is a mechanical advance much like the Mallory Unilite? I've been looking at those, but not really wanting to pay that much until I cover all of the basics first. I cannot wait to get this thing sorted out, I want to drive it!!
Thanks again guys!
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By lowrider - 10 Years Ago
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Ryan, one thing I did at first was to get the engine to run good with just the center carb on it and the secondary carbs blocked off with plates. Once you get it to run good on the one carb you don't have worry about that one other than maybe a slight mixture adjustment. If it runs good on the one carb but falls on its face when you add the others you know where to look.
The dist. is just the regular yblock dist. housing with late 70's Ford Duraspark guts, wired to a Ford Duraspark module.
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By Ryan New Mexico - 10 Years Ago
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Ok guys here is the run down.
I put tape over the top of the secondary carbs. The engine was an absolute chore to start. I needed to drastically increase the idle screw, and really fiddle with the two mixture screws. I had thick smoke rolling out of the Lake Headers and the vacuum was around 8 (max). I kept leaning out the idle screws and got it to run ok, but the exhaust was still dark. I took it around the block with no stumbling.
I pulled the tape off of the first (front) outer carb and it ran smoother, pulled tape off of the last (rear) secondary carb and it ran even better. Smoke went away and I fiddled with the idle mixture screws again, then turned the idle screw out a ways to slow it down and it ran smooth, with 18 lbs vacuum with the car in gear.
I run it down the road and it pops and backfires out of the carb, then I manage to throttle it up past the stalling stage of acceleration and it either takes off or shoots a 1' flame out of the carbs. I am ready to throw this POS in the trash and get a simple 4 barrel carb.
Do any of you guys have any ideas that could help me salvage this money pit intake and carbs,or do you have a good intake and carb setup to sale me, haha.
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By miker - 10 Years Ago
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Well, I remember that level of frustration. But several guys here seem to be able to make the tri power setups run right.
First thought is that when you taped off the end carbs, you put manifold vacumn all the way up both carbs. So you were sucking fuel out of the end carbs, but adding no air. I guess in theory the butterflies might make a perfect seal, but I doubt it. It explains why all the black smoke, since you're really rich. Cutting down the idle mixture on the center carb idle screws helped, but didn't solve the rich condition. But, you say it drove ok, and didn't stumble.
When you pulled the tape, you basically went back to where you were if I understand right. Since the engine ran when it was rich, I'd rule the ignition out. I think you really need to take a look at the butterflies on the end carbs for fully closed. Or do the block off like was suggested above till it runs good on the center carb.
A big stumble on acceleration, followed by a backfire thru the carb, is often a lean condition. If the end butterflies aren't closed you probalby can't get enough fuel thru the center carb idle/transition/accel pump to cover that lean a condition. Once the rpm is up, and the main jets/Venturi is providing mixture you can probably get away with it. I guess I'm trying to say leaking a little air from the end carbs is a big problem at idle and off idle transition, but not so much by half throttle, if you can get it there.
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By Ryan New Mexico - 10 Years Ago
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Well, I machined up two plates and blocked them (Front & rear secondary's) off at the intake. The motor starts an idles ok. I turned each mixture screw in until it started to stumble then backed them off. When I rev the motor it still stutters and pops, then I get back fire in the carb. Once I get past this dead zone by manipulating the throttle it runs perfect, I am somewhat confident my timing is correct. When I back the mixture screws all the way it still sputters and backfires in the carb.
When I was tinkering with all three carbs prior to blocking them off, with the car in gear, I was getting 18 lbs of vacuum, my power valve is a 4.5. Is this power valve adequate or is this something that would have little effect with this?
Thanks a lot guys for any help you can lend.
Here is a quick video (sorry not the best), but you can see the backfire and hesitation I am talking about. I am running lake headers with baffles so if you hear anything funny it is the sound bouncing around in my garage.
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By lowrider - 10 Years Ago
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Mikers description of your problem is dead on. Stay focused on getting it to run on the center carb then go from there. Make sure you have a good squirt from the accelerator pump and the venturi nozzles are clean. Match the power valve to engine vacuum. It needs to be half of whatever manifold vacuum is. Once I put the new secondary throttle bases on mine it run fine for a bit then started idling too fast again. I sprayed carb cleaner around the carbs looking for a vacuum leak and found the throttle shaft was loose in the primary carb. Installed another base on it and it has been running great ever since. I was a bit surprised how much of a difference it made. If you don't have another base you can get oversized ones from Vintage Speed along with the power valve. Hang in there.
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By Ryan New Mexico - 10 Years Ago
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Thanks Dan,
I will check out those bases and power valves. I did order a new pump actuator and pump link from there as well. I do think the acc pump is a little weak on the primary. I've seen that there are acc pumps with a .750 slot (the one I have) and one with a .625 slot that is supposed to give you a little better squirt. I will try to hunt that down as well.
Thanks, Ryan
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By Ryan New Mexico - 10 Years Ago
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Ok guys, I figured I would update everyone, so maybe anyone in a like boat, may have it a little easier than I did.
Originally I ordered a Ignitor 3 and a Flamethrower 3 from Pertronix as well as a reman Cardone Dist. Well, because the distributor was on a bearing race, the ignitor 3 will not work with that distributor. I called Pertonix they confirmed so I sent the ignitor 3 back for a 2, but kept the flamethrower 3. Here is the first mistake I made. The Flamethrower 3 can only be used with the ignitor 3, "it ill not work right with the ignitor 2" was the exact quote from Pertronix tech line. I threw in a MSD Blaster 2, and it helped a ton. I was still getting some popping in the intake and the exhaust. While I was jacking with the distributor I had my hand resting in the coil wires and when I rev'd the motor I got bit. So then I knew I am also getting crossfire, from my Ebay coil wires. I swapped out the wires with the MSD wires and also installed a MSD distributor (I ordered prior to finding out about the coil), and this thing runs worlds better. I still have a little air sucking in from the secondary carbs, but I have 4 new butterflies coming in tomorrow to swap out this weekend to get a better seal, then I think this thing will become my friend again. hahaha...
I can't say enough about this board and all you fellas that are on here day in and day out, I for one have learned a lot and would like to say thanks again for all the suggestions and support I was given.
Later fellas!
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