Trying to get my 347 to fire, Help please!

problemCOBRA94 · January 6th, 2008, 04:04 PM

ok. It is not the coil. I got a new one. I also tried a new fuel pressure regulator. At the coil the voltage reading is about 9volts and it should read the same as the battery. Chilton's says to replace the ignition switch... Mine is fine, it cranks. I check the wire harnesses and they are fine. I am pretty sure that there is no spark because there is not enough power to the coil because the fuel pump is running and developing a voltage drop...

I am sure that If I can get the fuel pump to function properly, I will get a spark because I will get full power to the coil.

So, How do I get the fuel pump to shut off? As soon as I connect the battery it turns on to pressurize the fuel rails and after that it should shut off. I know the injectors are not spaying either. The sound I mentioned before was just fuel flowing through rails and back through the return. So, what tells the fuel pump that the rails are up to pressure? Or what tells the fuel pump to shut off?
I already ruled out all of the following...
injectors
fuel filterfuel
pressure regulator
fuel lines flow freely
coil
ICM (for the old guys TFI)
I cant find any bad wires, bent pins, etc.

Stangzilla · January 6th, 2008, 04:28 PM

Originally Posted by problemCOBRA94

ok. It is not the coil. I got a new one. I also tried a new fuel pressure regulator. At the coil the voltage reading is about 9volts and it should read the same as the battery. Chilton's says to replace the ignition switch... Mine is fine, it cranks. I check the wire harnesses and they are fine. I am pretty sure that there is no spark because there is not enough power to the coil because the fuel pump is running and developing a voltage drop...

I am sure that If I can get the fuel pump to function properly, I will get a spark because I will get full power to the coil.

So, How do I get the fuel pump to shut off? As soon as I connect the battery it turns on to pressurize the fuel rails and after that it should shut off. I know the injectors are not spaying either. The sound I mentioned before was just fuel flowing through rails and back through the return. So, what tells the fuel pump that the rails are up to pressure? Or what tells the fuel pump to shut off?
I already ruled out all of the following...
injectors
fuel filterfuel
pressure regulator
fuel lines flow freely
coil
ICM (for the old guys TFI)
I cant find any bad wires, bent pins, etc.

Like I told you b4 there is a relay that triggers the pump..

problemCOBRA94 · January 6th, 2008, 05:29 PM

I don't want you to hold my hand or anything but where is the relay? in the engine compartment fuse box?

Stangzilla · January 6th, 2008, 06:22 PM

Originally Posted by problemCOBRA94

I don't want you to hold my hand or anything but where is the relay? in the engine compartment fuse box?

So what do you call what we have been doing so far?

problemCOBRA94 · January 6th, 2008, 07:22 PM

ok, I set you up for a cheap shot. Your welcome.

If you are done beating me up do you have any other ideas.

what tells the fuel pump that the rails are full, and what stops the fuel from free flowing through the return?

I can't believe I haven't figured this out yet. I had a ford mechanic look at it and he said, "good luck." then walked away.

Stangzilla · January 6th, 2008, 08:08 PM

Originally Posted by problemCOBRA94

ok, I set you up for a cheap shot. Your welcome. If you are done beating me up do you have any other ideas.

what tells the fuel pump that the rails are full, and what stops the fuel from free flowing through the return?

I can't believe I haven't figured this out yet. I had a ford mechanic look at it and he said, "good luck." then walked away.

The rails dont get "full" in the sense you think they do. They are "full" with flowing fuel. The fuel in the system is always flowing through the return. Its the fuel pressure regulator that keeps the set pressure when the pump is on and a check valve that maintains pressure when the pump is off weather it be the stock style that is not adjustable or an after market adjustable that mounts on the fuel rail. Or if you have high flow billet rails like I do my adj. reg is mounted on the strut tower. Or you can get the block off plate for the stock rails and run the style like I have. Anyway...

1/4-horse · January 6th, 2008, 08:35 PM

I would think that the pump shouldn't run unless the key was on. Before I converted my car to carb'd that's how mine was. There was (is) a switch under my drivers seat that powers the relay for the electric pump, I shut that off and added a carbed pickup. The pump shouldn't run when the battery is hooked up w/o the key on, otherwise it'd kill the battery sitting overnight! I think you've either misplaced wires, or you've got something backwards. Get out the Chiltons, or better yet find a FSM, and trace the fuel pump circuit. It's gotta be something you did when you did the swap. Sorry, but thats how it is.

Good luck, bro.

Jay

ryans88gt · January 6th, 2008, 09:09 PM

Probably a bad relay located under the drivers seat.

problemCOBRA94 · January 6th, 2008, 10:30 PM

Whooo hooooo!!!!!! I got it.... human error! Fuck me. At least I didn't actually fuck up something big. It was a swapped wire harness. Let it be know that on a 94 cobra, the abs harness and where the fuel pump harness makes a continuation by the abs distributor, the harnesses are the FUCKING SAME! I thought nothing of it when I was originally doing all the wiring because I didn't thing ford would put two harnesses (four connectors) that all match within about 3 inches of each other!!!

Anyways, The motor runs smooth as a kitten and off of old 87oct. gas. I thought I wouldn't run so good on pump gas because it is a 347 with a compression ratio at the deck of 10.5:1 and I put on 58cc combustion chamber heads. Oh well. I is pretty sweet. I built this motor in every way except for the short block, I had assembled.

All I have left to say is... THIS IS FUCKING AWESOME!!!

Thank you to everyone that helped me along the way. These forums actually work. lol

I will post some pics ASAP.

Stangzilla · January 6th, 2008, 10:32 PM

Originally Posted by problemCOBRA94

Whooo hooooo!!!!!! I got it.... human error! Fuck me. At least I didn't actually fuck up something big. It was a swapped wire harness. Let it be know that on a 94 cobra, the abs harness and where the fuel pump harness makes a continuation by the abs distributor, the harnesses are the FUCKING SAME! I thought nothing of it when I was originally doing all the wiring because I didn't thing ford would put two harnesses (four connectors) that all match within about 3 inches of each other!!!

Anyways, The motor runs smooth as a kitten and off of old 87oct. gas. I thought I wouldn't run so good on pump gas because it is a 347 with a compression ratio at the deck of 10.5:1 and I put on 58cc combustion chamber heads. Oh well. I is pretty sweet. I built this motor in every way except for the short block, I had assembled.

All I have left to say is... THIS IS FUCKING AWESOME!!!

Thank you to everyone that helped me along the way. These forums actually work. lol

I will post some pics ASAP.

just so you know you should have no problem running premium unleaded with that compression. I run 11.1 on pump gas with no problem at all

e3sean · January 7th, 2008, 01:25 AM

Originally Posted by problemCOBRA94

Whooo hooooo!!!!!! I got it.... human error! Fuck me. At least I didn't actually fuck up something big. It was a swapped wire harness. Let it be know that on a 94 cobra, the abs harness and where the fuel pump harness makes a continuation by the abs distributor, the harnesses are the FUCKING SAME! I thought nothing of it when I was originally doing all the wiring because I didn't thing ford would put two harnesses (four connectors) that all match within about 3 inches of each other!!!

Anyways, The motor runs smooth as a kitten and off of old 87oct. gas. I thought I wouldn't run so good on pump gas because it is a 347 with a compression ratio at the deck of 10.5:1 and I put on 58cc combustion chamber heads. Oh well. I is pretty sweet. I built this motor in every way except for the short block, I had assembled.

All I have left to say is... THIS IS FUCKING AWESOME!!!

Thank you to everyone that helped me along the way. These forums actually work. lol

I will post some pics ASAP.

glad we could help

Iwannagofast · January 7th, 2008, 03:07 AM

now go haul ass

ryans88gt · January 7th, 2008, 12:10 PM

Lets see some pics or video

NOSLO5.0 · January 13th, 2008, 11:11 AM

Mount Kisco

Speedstang302 · January 13th, 2008, 12:09 PM

pics or video or die!!!! or ban for you anti-violence queer-bags!!!!

Stangzilla · January 13th, 2008, 01:55 PM

Originally Posted by NOSLO5.0

Mount Kisco

Ok kool I live by Poughkeepsie, not to far away.. Keep me posted on gatherings cruises ect...

NOSLO5.0 · January 26th, 2008, 08:31 AM

ditto!

January 6th, 2008, 04:04 PM	#41
problemCOBRA94 Regular 1994 Mustang Cobra it runs now. Kinda... Join Date: Mar 2007 Location: Rocklin, ca Posts: 72 iTrader: 0 reviews	still no solution. ok. It is not the coil. I got a new one. I also tried a new fuel pressure regulator. At the coil the voltage reading is about 9volts and it should read the same as the battery. Chilton's says to replace the ignition switch... Mine is fine, it cranks. I check the wire harnesses and they are fine. I am pretty sure that there is no spark because there is not enough power to the coil because the fuel pump is running and developing a voltage drop... I am sure that If I can get the fuel pump to function properly, I will get a spark because I will get full power to the coil. So, How do I get the fuel pump to shut off? As soon as I connect the battery it turns on to pressurize the fuel rails and after that it should shut off. I know the injectors are not spaying either. The sound I mentioned before was just fuel flowing through rails and back through the return. So, what tells the fuel pump that the rails are up to pressure? Or what tells the fuel pump to shut off? I already ruled out all of the following... injectors fuel filterfuel pressure regulator fuel lines flow freely coil ICM (for the old guys TFI) I cant find any bad wires, bent pins, etc.

January 6th, 2008, 08:35 PM	#47
1/4-horse Regular 1987 LX vert/ 1984 LX 460 slow/stopped Join Date: Jan 2007 Location: 48188 Posts: 72 iTrader: 0 reviews	I would think that the pump shouldn't run unless the key was on. Before I converted my car to carb'd that's how mine was. There was (is) a switch under my drivers seat that powers the relay for the electric pump, I shut that off and added a carbed pickup. The pump shouldn't run when the battery is hooked up w/o the key on, otherwise it'd kill the battery sitting overnight! I think you've either misplaced wires, or you've got something backwards. Get out the Chiltons, or better yet find a FSM, and trace the fuel pump circuit. It's gotta be something you did when you did the swap. Sorry, but thats how it is. Good luck, bro. Jay __________________ I'm rapidly getting addicted to this Fox body Mustang thing.

January 6th, 2008, 09:09 PM	#48
ryans88gt MM Fanatic Join Date: May 2007 Location: Bloomington, IL Posts: 4,737 iTrader: 0 reviews	Probably a bad relay located under the drivers seat. __________________ 88 GT CHI headed 351w 10.8 @ 125 - still figuring it out. 03 Cobra 2.3 whipple 10.7 @ 129 - sold it 04 Mach 1 12.7 @ 109 mostly stock - sold it 89 LX procharged 302 515 hp 497 ftlbs 10.7 @130 mph - sold it

January 6th, 2008, 10:30 PM	#49
problemCOBRA94 Regular 1994 Mustang Cobra it runs now. Kinda... Join Date: Mar 2007 Location: Rocklin, ca Posts: 72 iTrader: 0 reviews	Whooo hooooo!!!!!! I got it.... human error! Fuck me. At least I didn't actually fuck up something big. It was a swapped wire harness. Let it be know that on a 94 cobra, the abs harness and where the fuel pump harness makes a continuation by the abs distributor, the harnesses are the FUCKING SAME! I thought nothing of it when I was originally doing all the wiring because I didn't thing ford would put two harnesses (four connectors) that all match within about 3 inches of each other!!! Anyways, The motor runs smooth as a kitten and off of old 87oct. gas. I thought I wouldn't run so good on pump gas because it is a 347 with a compression ratio at the deck of 10.5:1 and I put on 58cc combustion chamber heads. Oh well. I is pretty sweet. I built this motor in every way except for the short block, I had assembled. All I have left to say is... THIS IS FUCKING AWESOME!!! Thank you to everyone that helped me along the way. These forums actually work. lol I will post some pics ASAP. Last edited by problemCOBRA94; January 6th, 2008 at 10:31 PM. Reason: After thought

January 7th, 2008, 12:10 PM	#53
ryans88gt MM Fanatic Join Date: May 2007 Location: Bloomington, IL Posts: 4,737 iTrader: 0 reviews	Lets see some pics or video __________________ 88 GT CHI headed 351w 10.8 @ 125 - still figuring it out. 03 Cobra 2.3 whipple 10.7 @ 129 - sold it 04 Mach 1 12.7 @ 109 mostly stock - sold it 89 LX procharged 302 515 hp 497 ftlbs 10.7 @130 mph - sold it

January 6th, 2008, 05:29 PM	#43
problemCOBRA94 Regular 1994 Mustang Cobra it runs now. Kinda... Join Date: Mar 2007 Location: Rocklin, ca Posts: 72 iTrader: 0 reviews	I don't want you to hold my hand or anything but where is the relay? in the engine compartment fuse box?

January 6th, 2008, 07:22 PM	#45
problemCOBRA94 Regular 1994 Mustang Cobra it runs now. Kinda... Join Date: Mar 2007 Location: Rocklin, ca Posts: 72 iTrader: 0 reviews	ok, I set you up for a cheap shot. Your welcome. If you are done beating me up do you have any other ideas. what tells the fuel pump that the rails are full, and what stops the fuel from free flowing through the return? I can't believe I haven't figured this out yet. I had a ford mechanic look at it and he said, "good luck." then walked away.

January 7th, 2008, 03:07 AM	#52
Iwannagofast Hardcore Enthusiast 1990 Mustang GT havent gone since gears Join Date: Feb 2007 Location: Arkansas Posts: 2,940 iTrader: 0 reviews	now go haul ass

January 13th, 2008, 11:11 AM	#54
NOSLO5.0 Newbie 1995 vert. x-mod na Join Date: Dec 2007 Location: New york-out there Posts: 15 iTrader: 0 reviews	Mount Kisco __________________ JASON ERIC BRESMON 1979-2004 TILL WE RIDE AGAIN A candle that burns twice as bright - lasts half as long

January 13th, 2008, 12:09 PM	#55
Speedstang302 I Post Entirely Way Too Much 1996 Mustang GT 13.64@101mph Join Date: Apr 2007 Location: Massachusetss Posts: 5,828 iTrader: 1 reviews	pics or video or die!!!! or ban for you anti-violence queer-bags!!!! __________________ 1990 GT- GT40p Heads\| Anderson N41 cam\| Crane 1.6 RR's\| Trickflow Intake\|MGW Short Throw\| Aluminum d/s\| 3.73's.....still slow....

January 26th, 2008, 08:31 AM	#57
NOSLO5.0 Newbie 1995 vert. x-mod na Join Date: Dec 2007 Location: New york-out there Posts: 15 iTrader: 0 reviews	ditto! __________________ JASON ERIC BRESMON 1979-2004 TILL WE RIDE AGAIN A candle that burns twice as bright - lasts half as long

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Trying to get my 347 to fire, Help please!

still no solution.