Too Much torque, Fuel Problem

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Too Much torque, Fuel Problem

September 05, 2005, 06:43:02 PM

The Cad-T-Bird is running fairly good now but one problem leads to another.

Now when I take off from hard launch it goes to 4500RMP and cuts out for a second. Go back to the house and I have fuel pressure, gas and everything, adjust a few things, take it out and same problem.

I finally took out the gas tank and now I think I see the problem. The pick-up is in the bottom center of the tank. I replace the stock pick-up with a 3/8 inch line that goes to the bottom back of the baffled area. I think that when I launch all the gas goes to the back and the pick-up goes dry. Too much torque. Ford put a small baffle in this area that holds about a quart but I think 500 inches eats this up pretty fast.

I can't extend the line to the back because Ford decided to make the back of the tank higher. I don't like the idea of always running with a full tank, so is a fuel cell in my future?

Never done a fuel cell, do they have to go in the trunk or can they go under? Any advice you can give would be great.

Any low cost solutions to my problem? Have you guys ever modified the stock tank to solve this kind of problem?
Thanks

TED

Re: Too Much torque, Fuel Problem

Reply #1 – September 05, 2005, 08:18:06 PM

ok where do i start 500cid caddy motor in a TBird wow

anyway today is your your lucky i happen to know alot about caddys

back in the late 80's and early 90's i used to race a 73 caddy fleetwood

you name it yes i had it on the car. even the 26/10.50/15's sportsmen pros on the rear with the skerts on the car and a holley blue pump on the rear bumper

anyway we will go deeper into this but i'll start here..

1, i see the have a point distributor so it's pre 1974
2,what year is the motor
3 are you sure it is a 500cid and not a 472 so what kind of car did you get it out of.. ie eldo,deville,fleetwood..
4 if i remember corectly it's bin a while:rolleyes: pre 1972 was 10.0to1 comp..

now where i feel the problem lies is mostly in the carb.. not in the tank..

my old .030 over 472 ran fine with the stock fuel pump i just wanted to upgrade to be safe..and the motor made 450HP@4400rpm's&650FPT@3000rpm's and redlined at 6500rpm's very well balanced.. i should have kept that motor :disappoin

anyway as i type this post i'm looking threw your pictures so bare with me.. before i go ferther ditch the point distributor get your self a HEI one.. if the points are'nt ajusted right it will pop at high rpm's..

and the other thing is your bog is caused from the seconderys opening to early.. you need to ajust them.. but you have to be very carefull when you ajust and i will tell you how to do it in this post..

to ajust the seconderys on the passenger side of the carb on the back of it where the secondery choke pull off is.there is a small screw.but it is locked down by another screw on the under side of where the secondery rod is. if you press on the secondery flaps and is seens real loose it needs to be tighted.. but like i said very carefully if you turn the side screw to much it will jump te spring off the rod.. then you would have to take the carb off to reset the screw..

i hope this helps and i can help more just ask away as we go along ;)

anyway a few more questions

i see your useing 81cc heads what pistons are you useing if there flat tops then you have 10.5to1 if they have a slite dish to them you have 8.5to1

wow i saw the rocker setup :evilgrin:

i don't know where you got them but there used to be a company called cadillac motorsports and that rocker setup was like 450 bucks.. and what intake maniflod is that? is that the black widow?
well that was the name cadillac motorsports gave it it was a holley strip dominator

i allso see you don't have the transmission kickdown hooked up or did you even know?

on turbo400's it's electric..

and i have a real trick t ohook it up like i did in my caddy

i'll be waiting for your next post i'm sure theres more to talk about

Nick

Re: Too Much torque, Fuel Problem

Reply #2 – September 05, 2005, 08:57:34 PM

Actually, since it is a turbo coupe, theyre known to have the 1/4 tank buck and fuel starvation, which mine occasionally gets with just a 4 banger

i dont know how good your fabriaction skills are, aparantly they must be rather good to do a swap like that, but you could possibly sump the tank, would would be pretty sweet, but then youll need to run an external pump

Re: Too Much torque, Fuel Problem

Reply #3 – September 05, 2005, 11:38:34 PM

A lot of the pictures are pretty old and I have made changes since then. I have a Pertronix kit in the distributor so the points are gone. The HEI would not fit, it hit the hood because of the big cap.

My original engine had late head with early pistons, After some changes I still had 11.5 to one compression. It had tons of power when I could get it runing but it also give me a ton of problems. A couple months ago a piston broke and distroyed the block.

I now have 5 engines and they are all 500's, 4 of them were from Eldorados and one from a 75 Sedan.

The engine in there now is a 75 Eldorado motor with 8.5 to compression. The heads are 120cc with 2.19 and 1.88 valves. I was lucky to find an engine with a fresh rebuild that was bored .030 (507). I threw in the cam from the old engine, Comp extream energy 274 (230/236 duration and 562 lift).

I also upgraded the rocker to an adjustable roller set-up. I plan to go to a solid cam in the future.

The carb has been all upgraded and jetted and has no bog at all. From a start I get nothing but all out power till 4500RPM and then a one second buck and then it recovers again. Does not happen with a full tank but anything under 1/2 tank and it gets worse and worse.

You were lucky to spin one to 6,500 with stock rods, I put my redline at 5,500. I think you made a bit more HP and Torque than mine does but it in the some range.

The kickdown is a kit for hot-rods and the switch is on the transmission and ran by a cable up to the carb. Works very well. By the way the cruise control still works.

Thanks for you comments and interest. I drive most of the people on this board nuts with me Caddy in a Bird.

TED

Re: Too Much torque, Fuel Problem

Reply #4 – September 05, 2005, 11:49:02 PM

From Tbird232ci "Actually, since it is a turbo coupe, theyre known to have the 1/4 tank buck and fuel starvation, which mine occasionally gets with just a 4 banger"

This is very nice to know, I'm not alone.

I think you are right I may have to weld in a rear sump and pick-up. I also been kicking around the idea of a swinging pick-up. I have an external pump now with 3/8 inch line going all the way up.

Is the rear sump the main solution? Or maybe just a full tank. I plan to run nitrous in the future and I don't want a chance of lean conditions.

TED

Re: Too Much torque, Fuel Problem

Reply #5 – September 06, 2005, 12:00:15 AM

i think rear sump would work best personally, and you can run a more simple inline pump, and if you had the cash, run some nice AN line, and have a bullet proof fuel system

Re: Too Much torque, Fuel Problem

Reply #6 – September 06, 2005, 04:05:37 AM

yes Eldorados those years only came with 500's or 368's same block they where doing away with the 472 and in the late70's went to the 425cid which was the same block as the 472&500's..

the only question i did'nt ask was what fuel pump are you useing? the stock caddy pump or the stock turbo coupe pump or something else?

the reason why i ask is..

the turbo coupe fuel pump pumps about 90-110lph or = about 30-40gallons an hour at 40 PSI..

where the stock caddy fuel pump makes about 70-90gallons or = about 264lph-364lph an hour but at 5-7 PSI..

what i'm trying to say is that a carb setup need alot more flow then it needs pressure..

where with a fuel injection setup it the other way around..
ie pressure not so much flow

even most pro street motors with a carb setup never go over 14 PSI but flow over 110+gallons"364 liters" an hour at that pressure...

so if you bought a inline fuel pump for like a mustang and lets say like the 190 liter "intank" and the Trex 190liter@70PSI"inline" i'm useing with the blower is fantastic for my EFI blower setup. but even if you had the same fuel system as me it would still be worthless for you..

like i said tons of pressure but about half the flow as a carb fuel pump..

so let me know what you have

*EDIT* and i looked at the picture of the motor and it looks like your useing the stock pump.. so only thing i have to ask is did you put a inline pump in allso?

check this link out http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1497&prmenbr=361

Nick

Re: Too Much torque, Fuel Problem

Reply #7 – September 06, 2005, 09:00:06 AM

I replaced the line front to rear with 3/8 inch steel line. I took out the stock pump and made a custom pick-up that ends at the back of the baffled area.

Running a Holley red in the rear. At first I was running the stock fuel pump also but I by-passed it think it might be causing my problem.

What do you think about running both pumps at once?

TED

Re: Too Much torque, Fuel Problem

Reply #8 – September 06, 2005, 10:23:09 AM

To answer your question about the fuelcell, they are generally mounted in the trunk. Also filled by opening the trunk, not something I'd want in a street car. (I'm sure there are probably filler necks available).

As far as the bog problem, I have the same thing if I try to launch it hard with less than half tank. I just consider the 1/2 mark as "E", and refill it. Since I probably only paid 1.25 for that first half tank, look at what its worth now. :hick: Plus it puts weight at the rear of the car where its really needed for traction.

Re: Too Much torque, Fuel Problem

Reply #9 – September 06, 2005, 03:58:10 PM

Just might be the solution.
TED

Too Much torque, Fuel Problem

Reply #10 – October 16, 2005, 02:39:29 PM

Quote from: Cad-T-Bird 500

The Cad-T-Bird is running fairly good now but one problem leads to another.

Now when I take off from hard launch it goes to 4500RMP and cuts out for a second. Go back to the house and I have fuel pressure, gas and everything, adjust a few things, take it out and same problem.

I finally took out the gas tank and now I think I see the problem. The pick-up is in the bottom center of the tank. I replace the stock pick-up with a 3/8 inch line that goes to the bottom back of the baffled area. I think that when I launch all the gas goes to the back and the pick-up goes dry. Too much torque. Ford put a small baffle in this area that holds about a quart but I think 500 inches eats this up pretty fast.

I can't extend the line to the back because Ford decided to make the back of the tank higher. I don't like the idea of always running with a full tank, so is a fuel cell in my future?

Never done a fuel cell, do they have to go in the trunk or can they go under? Any advice you can give would be great.

Any low cost solutions to my problem? Have you guys ever modified the stock tank to solve this kind of problem?
Thanks

TED

wow, keep in mind this is with my 429/c-6 car also

I dont know were to start except that i finnally got my car running as it should. We got her out last night to roll over to a cruise in about 30 mins away trip there we drove easy with no problems no sputtering,popping,overheating etc.

Well the problems began when i heard the words "get on it" well of course lets see 1/4 mile long straightaway + no one in the way so i layed into it got sideways for about 40-45 ft and then got real soft feeling like it had had the timing retarded well i stop at the end of the road to pull out still running . turn onto the main rd and bluuuuuhh it dies . NO FUEL PRESSURE. ok get it back started go to the gas station up the rd put 10 gal in it everything is ok tilll.......
i get on it again then about 20 sec later it dies so im like hmmmmm
NO FUEL PRESSURE.let it sit for a min then it builds its normal 7 psi back on the way home no other problems till i turn on our rd we live on like an 1/4 mile away from the end .stop stage it up let her go 1st,into second looses power make it to the driveway and blahhhh it dies again same thing .

keep in mind i run 1/2 fuel lines and a holley blue pump with regulator and the pickup is also 1/2 in the stock location about 1/8 off the bottom of the tank...

i see a fuel cell in my future .... cant have these problems when i start to spray it with the big shot kit.

did you ever get yours fixed?

Too Much torque, Fuel Problem

Reply #11 – October 18, 2005, 09:26:17 PM

??:)

Tank

Reply #12 – October 21, 2005, 12:46:04 AM

The only fix I had was to make sure it was completly full of gas at the track. As long as I have over 1/2 I have no problems. I wish that I had your improvements, I'm running a 3/8" line and I think I may have to up-grade in the long run.

You did make it down the track OK so you must have figured it out somewhat?

TED

Too Much torque, Fuel Problem

Reply #13 – October 21, 2005, 12:58:18 AM

Quote from: Cad-T-Bird 500

The only fix I had was to make sure it was completly full of gas at the track. As long as I have over 1/2 I have no problems. I wish that I had your improvements, I'm running a 3/8" line and I think I may have to up-grade in the long run.

You did make it down the track OK so you must have figured it out somewhat?

TED

it had about a half tank at the track really didnt start to see it till i got it running at close to 100%

hope to have some mid 7 motor passes tommorow night if the rain hold off!

Good luck!

Reply #14 – October 21, 2005, 01:08:39 AM

Hope you do great, let us know.

The track is closed here for the year, only made it one time, have to wait till next year :( I'm going to move down your way.

TED