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Aritcle - Top-End Torque

 
mc302stang
New User
Posts: 34
Joined: 06/08
Posted: 07/19/13 06:35 AM

What injectors did you go with, stock 19 lbs? I have TFS Twisted Wedge Street heads and an Edlebrock Performer II intake with 24 lb. injectors but once the car hit 100 mph the power just stopped. Showed good hp on the dyno but on the street it was lacking. I am using Ford's E-303 cam. Did you have the same problem, if not, why did I? I put on a Supercharger with about 5 lbs of boost and that solved my problem, but I would like to understand why?  

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waynep712222
User
Posts: 124
Joined: 03/13
Posted: 07/20/13 09:32 AM

hopefully somebody in the staff will see this..

what you might want to monitor is the injector pulse width..   you can do this with a digital volt meter that has a MS.. millisecond setting.. some meters have this..  you can visit the import section of the junk yard..  in saabs and volvos.. you can find the male and female connectors for the fuel injection on your mustang... either in the oxygen sensor wiring or antilock brake wheel speed sensor wiring..   connect the wires so you have a male and a female connector only a few inches apart. but put these into ONE end of a crimp terminal.. in the other end.. extend the wiring ..  now.. you can unplug one injector.. plug this break out harness in.. and monitor the injector pulse width easily..

you might also want to monitor the fuel pressure.. or electric fuel pump amp draw.. you might have reached the max volume the pump can put out and the fuel pressure might be dropping..

it does take a significant amount of fuel to support a lot of horsepower...

i am also taking that your fuel filter is clean.. been replaced recently.. this will cut of the power at high speeds..

one company sells a really neat EECIV device that allows you to monitor all the live data streams the computer is seeing..  this is done with a laptop...  

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waynep712222
User
Posts: 124
Joined: 03/13
Posted: 07/20/13 09:45 AM

you might also want to watch this video...

http://www.youtube.com/watch?v=Emnax2J4FX4

there is another one out there similar to this thats more to your area of need...but i cannot find it..  

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mc302stang
New User
Posts: 34
Joined: 06/08
Posted: 07/21/13 09:11 AM

Thanks, interesting to watch. That was my previous set up. Now I have a new Boss 302 with Ford 42lb injectors. Same amount of boost, and after cleaning, tightening, and replacing connections it runs a lot better. I still wonder since I have the TFS heads if I should use a different cam. It puts down about 400 rwhp (dyno'd on a day when the temp was 105, might be a tad more) which is plenty for the 245's I have on it.  

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mc302stang
New User
Posts: 34
Joined: 06/08
Posted: 07/21/13 09:15 AM

Almost forgot, lately when I take the fuel cap off there is this big 10 second long suction noise. Normally, it is just a quick pssshdt sound. Why would that last for a few seconds like that? I put on a new fuel cap, still does it. I know it has something to do with the vacuum, maybe because I have two fuel pumps pulling...? Frown  

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waynep712222
User
Posts: 124
Joined: 03/13
Posted: 07/21/13 11:59 AM

Almost forgot, lately when I take the fuel cap off there is this big 10 second long suction noise.


wow... thats an issue that could cause problems.

i have not looked at what year your car body is... and how you have hooked up the vapor emission system from the fuel tank..

ah... you have a 1989 mustang..

is there still an emissions label on the radiator core support. or under the hood.. got a picture of it..???

i really can decipher it..  

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waynep712222
User
Posts: 124
Joined: 03/13
Posted: 07/21/13 12:31 PM

in looking at some of the vacuum diagrams..


the fuel tank vapor system is hooked up the same way..

vent hose from the gas tank to the carbon canister..

hose from the carbon canister to a electric solenoid valve to prevent vapors from leaking when the ignition is off..   there is also a vacuum restrictor valve inline to limit the amount of flow..


0900C1528006935d

notice the notch in the vacuum hose from the carbon canister to the engine.. thats the vacuum restrictor..

you can also see the electric solenoid vacuum control..


0900C15280069374

0900C15280069375


0900C15280069367

Note which hose is connected to each side before removing the purge control valve

The purge control valve is in-line with the carbon canister and controls the flow of fuel vapors out of the canister.

When the engine is stopped, vapors from the fuel tank flow into the canister. On controlled systems, the vacuum signal is strong enough during normal cruise to actuate the purge control valve and vapors are drawn from the canister to the engine vacuum connection. At the same time, vapors from the fuel tank are routed directly into the engine. On some systems where purging does not affect idle quality, the purge control valve is connected to engine manifold vacuum and opens any time there is enough manifold vacuum.

another section
The purge solenoid valve is in-line with the carbon canister and controls the flow of fuel vapors out of the canister. It is normally closed. When the engine is shut off, the vapors from the fuel tank flow into the canister. After the engine is started, the solenoid is engaged and opens, purging the vapors into the engine. With the valve open, vapors from the fuel tank are routed directly into the engine.

does any of this help...

also.. dig thru your receipts... or trashcan.. can you supply the part number of the fuel cap you purchased that did not cure this issue..

there are several versions that might fit and have flow in both directions.. warning..

if you allow vapors out of the fuel tank.. you will probably have a smelly garage..

a lot of people with attached garages have started installing and hooking up carbon canisters to trap the gasoline vapors to reduce the smells in the garage..  

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mc302stang
New User
Posts: 34
Joined: 06/08
Posted: 07/21/13 05:12 PM

Oh man!!! Thanks for showing this to me. I know exactly what the problem is. I thought there was something missing down there when I was messing with the air filter. The Canister is gone. I guess I will have to give them a call and tell them that was not supposed to come off - you think they would have known that. Ugh!  

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waynep712222
User
Posts: 124
Joined: 03/13
Posted: 07/21/13 06:37 PM

hmmm.. brings back memories..  and not really great ones..

on a friends slightly over 100 foot wooden power boat.. he had been transferring fuel from the left tank to the right tank to try to rid the boat of the massive list it had because of the massive stack of 20, 22, 24' 2x12 planks on the left front deck..  as the captain/owner started the engines.. i noticed he had not opened the vent on the Day tank..  and that was FULL to the top.. he did not want to listen to me about that vent being closed.. along with all the other valves except to the 2 main 6-71 detroits and the 25KW with a ford layman diesel 4..  half way down the rock lined harbor channel. the left main engine died.. then the right.. then the generator set..  let me set the image.. 180 foot wide rock lined channel..  100 foot wooden hulled boat going 5 knots without power..  had to drop anchor in the middle of the channel to avoid going aground and sinking it.
when we got into the engine room to restart the engines.. i reached up and opened the vent valve.. it must have had a sucking sound for 15 seconds..  took 2 hours to change the filters and get the 3 engines restarted..  and that was the beginning of that voyage..   you can actually see where the boat currently is.. if you have google maps..  find the santa barbara city cemetery.. look offshore about a quarter mile. you will see a rectangular barge there.. just south of the barge if you zoom in.. you will see an boat outline.. if you look close.. its sitting on the bottom.  its only in about 35 feet of water and should be a great dive spot.. but i have not heard if anybody is diving on it..

as the engines used the fuel .. the level dropped creating vacuum.. when the vacuum was high enough to prevent the diesel injection pumps from pulling any more fuel out of the tank.. the engines died..

i would think that on your coyote motor.. that you are going to need to find a vacuum port that is NOT MANIFOLD VACUUM.. but only has vacuum OFF IDLE.. or ported vacuum..

you don't want manifold vacuum in the fuel tank..  it will CRUSH IT..  OBD2 systems have a pressure sensor on the top of the fuel tank.. or in the vent hose assembly.  and the OBD2 system can control the vapor pressure inside the fuel tank to keep vapors from escaping.. and to prevent the fuel tank from expanding from pressure or contracting from vacuum...

if your car has been put together for a while.. you might want to check the tank for signs of cracks from expansion and contraction..

what year did the coyote motors come in so i can examine the vacuum diagrams.. see if i can pot the proper purge port..  

you might want to look at the coyote PCM and see if you need to wire in  a fuel tank pressure sensor and the OBD2 style vapor emission devices ..  which kinda would be overkill..

there are mechanical vacuum valves on most GM cars from the mid 70s thru the early 90s that could be used to control the vacuum pressure in the tank..  that is if you have a ported vacuum source on the throttle body ..  

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waynep712222
User
Posts: 124
Joined: 03/13
Posted: 07/21/13 07:07 PM

there is one last option.. the gas cap..

the standard locking gas cap is a

CST 5501 with a key and a shutter door over the key.. locking type vented.
a
CST 6817 as a standard cap   vented

a

CST 6819 with a push button vent..  vented  

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mc302stang
New User
Posts: 34
Joined: 06/08
Posted: 07/24/13 02:06 PM

Oh, sorry for the confusion. When I said Boss 302 I did not mean the 'new' coyote engine. This is one of Ford's redesigned blocks using the single cam. Improved cooling and 4 bolt main vice the two. I added all forged internals and had it internally balanced. I wish I had a coyote motor, that would be something. I think I will just replace the charcoal canister(or make one) and run a line from it to the back of the car somewhere. Or, feed it back to the engine like it was...  

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