I have a new crate 350 truck motor. Low compression 190 hp (est) in my 36 Ford roadster. On it is a tri power set up as follows: Early Offy intake with 3 2GC's. Proper secondaries,(they shut tight), mild primary set up for a mild motor. The problem is that it takes forever to start. Once started, it'll run fine all day long and start up every time. Leave it for a week and bingo, real hard start. Put in a small electric pump to pump up to the carbs and no luck with that. I have a sneaky feeling that the runners may not match up that well and the intake is "flat" meaning that the fuel may be sitting in the main plenum and not running down the runners right away and perhaps the compression isn't enough to **** the fuel down the runner until, well, you pour enough gas into it. I have a 4 bbl manifold and edelbrock carb read to go, but I love the set up as it's all polished and stuff. If it's something that can be worked out, that would be my first choice. Any and all helpful hints will be very much appreciated. Happy new year to all you hot rodders out there..we are a dying breed!
what's your starting procedure? Does it include any throttle pumping after the electric pump has run a bit? got a choke? Does it close all the way?
Hi Dan: I turn on the pump a let it pump for a half minute or so, then I pump the pedal "alot!" , let it sit for a few minutes then start to turn it over. Has to turn over alot before I get a "spark", i.e, it pops a little thru the carb. Now I know I have fuel. Then I tuen it over a couple more times and it starts like there was never a problem. Wierd. I installed a choke after a year or so. And yes, when I checked it last week it was not a closed fit. I readjusted it last week and it did improve but by then I had already got it started so I don't know if that was the problem. It may help but I don't think that was the extent of the problem.
Is it a manual or automatic choke? If automatic, is it an integral or divorced choke? Is the choke heated electrically, by an external hot air tube from the exhaust manifold, or from the heat crossover in the intake manifold? Is there a working vacuum choke pull-off on the primary carb? Maybe a couple good pictures of the top of your engine from a few different angles would help to sort out exactly what you're working with.
I wonder if this is the more than common problem withrochester tri power carbs. The fuel bowls go dry after sitting and the whole system needs refilled. How's it start if you start it every day ? There are a dozen or so opinions on fixing this and most of them involve an elaborate fix for a minor problem. The car sits and doesn't start. It sits in your garage and this is where it doesn't start. Just keep a primer bottle of fuel on the shelf- giver her a squirt and off you go.
My tri-power set up is hard to get started if it sits for a month or so, I didn't hook up the choke on the center carb to keep things cleaner so I just deal with it. I'm using 94's on a crate 290hp 350.
Hi ClayMart: It's a typical electric choke set up, operated electrically. It works properly i.e., closes properly and once started it will react as a choke would. Pull off works. I got a bit better improvement when I closed it a bit more on the choke close spring but it's still a bear. I also may have spotted a possible culprit. I have a Cagel regulator which operates on va***. That is, it regulates the fuel pressure based on a va*** from the carb. Nice idea but it that is not working perhaps it's not letting fuel up in the bowl , at least not enough to get her started. I think I will by p*** this and see if that may be a cause. Who knows....but it's worth a try....
I think that is the problem but something is getting in the way of filling the damn carbs up with fuel or I'm not performing a proper start sequence. I read somewhere that fuel bowls need to be full to get a car started properly. I have a Cagel fuel regulator that operates on va***. Thye don't make these anymore. I this is restricting the fuel upon starting, it'll take forever. I'm going to by p*** and see what happens. Once started, it'll start all day and I do remember that once started and driven, it'll start the next day no problem....need to look at this some more. Your jarring my thought process I think in the right direction. Thanks..let ya know the results.
My brother had a hard start with his 94's on a 331 Caddy which operated on a straight linkage. he solved the problem with progressive linkage and getting secondary bases that closed shut. That solved it but in the end he switched to a 4 bbl as he had old 94's that looked more like a fire hazard than a carb!! Thanks for your help!!
That's a common problem. The correct no touch fix is start it every day. I've never had any trouble with priming the carb throats and lighting it off. Of course this required r&r of the air filter.
Just messed with a J2 olds setup that was pretty similar. All 3 carbs were basket cases with mismatched parts. Put them all together and it was hard to start and would even stall occasionally. The stalling seemed to be the primary float just hanging up on the pump well and keeping the needle from reopening after filling, a small dent fixed that. The hard starting was due to an incorrect and too weak accelerator pump diaphragm spring that would only squirt if you completely floored it. Also make sure the pump circuits are clear and check balls are in and free, some have 2 and the aluminum one under the pump can corrode and get fused in place.
I have the same set-up on my 350, and the same problem, or I should say non-problem. It's like 31 Vicky said if the fuel bowls empty out they're a little hard to start, an electric pump helps but it takes a little cranking to get them to fire. In the spring after it's been sitting all winter I turn the ignition on and let the electric pump run for 30 or so seconds, push the pedal about half way down, pull the choke and crank it. It will start after about 6 or 8 revoloutions. I've had these Rochester 2GC tri-power set-ups on all but one of my hot rods since the 60s, it's just how they are. Small price to pay for that look.
Take the air filter off your center carb, before you do any priming with the pump and cycle the accelerator pump and watch for a squirt. That will tell if you have gas in the carb.Then prime it with the electric pump and try the test again. That should tell you about your fuel delivery.If the carbs full and your choke is closed it should fire pretty quick or you have another problem. Gary
My truck starts hard after setting a few weeks(I like to start it once a month during the winter) but i look at this way i'm bulding up oil pressure before it starts
Are you getting a good accelerator pump shot? If its not working very good then the symptoms you mention will happen. Never had problems with my Trips and I have been running them for 20 plus years.
Good question, havent had a light on it for awhile. But I usually run it a bit advanced for better off the line performance an keeps the heat down. thanks.
I have a tri power set up on my 50 Olds convert w/ J2 built by Ross in Ohio. Starts at the push of the ****on everytime. But he set it on the dyno which is the best way to do it. If I can get my 36 to start like that I'll be happy. I'll figure it out with all the ideas the guy's offered in this trail. If not, well, I'll set it up with a 4 bbl that looks old timey. Thanks for your input.
Funny you mention the one way valve. I was looking at my parts bin yesterday and there was one I used on an older project. Aircraft type. Worked well. I was thinking like you. Prevent the gas from falling back to the tank. Thanks!
You should get plenty of gas when you pump the throttle before starting as the front and rear carbs still have accelerator pumps just like the center. So you actually get 2 times more than just a 2 bbl.
Until you have time to check to see how much gas gets squirted when starting it cold, it's hard to advise the next step. I agree with Roadster1927 in post #14. Once you've done what he recommended, then you'll know what direction to take.
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