V8 Swap, No Start

[Craig0320]

It was a 5.0 Mustang cam, but yeah. Crazy stuff happens. Physically fit just fine, but way too much duration.

I was completely convinced it was for an ls. Don't know how that came about. Lol

 

[Broosedamoose]

I haven't checked them physically but that are supposed to be 15.95 ohms.. They are Ford Racing BB302 30lb Fuel Injectors Genuine Bosch 0280155759. I checked the specs on them before I bought them to be sure they would work. I loaded the tune from decipha today and it sputtered a few times then just cranked. I could smell fuel so at some point the injectors are working. Any chance this could be a timing issue? Like if he didn't put the cam synchronizer in with the engine set at the right place? I'm just getting really frustrated here and my mechanics about to give up! He's been over the wiring harness several times and there is nothing wrong with the wiring!

 

[RonD]

I would test an easy to get to injector, under 20ohms is fine

The CAM pulse out of time might cause rough running, well would cause, but it would run
No cam pulse could cause no injectors on some software

 

[Broosedamoose]

Tested two of the injectors and got 16 ohms on both. I've been checking out carburetor set up's and they are not too expensive. I hate to give up on this but what else can we do? We've been over the wiring several times, done everything everyone suggested and the damn thing still won't run! It's got to be some stupid little thing we are missing but what? Like you said, it's not a complicated system! Only thing left is to try stock injectors and buy a new cam sensor. I hate to just throw parts at it hoping it will work though! Damn this is so aggravating!

 

[Broosedamoose]

I just got back from the garage. I had my mechanic hold the throttle plate open (cable's not hooked up yet) and it tried to start several times! It like fires and stops, fires and stops. That’s more than it’s ever done! Almost like it's not getting enough fuel to keep it running! Gonna recheck the fuel rail pressure. It was at 64 psi last time we checked it and the fuel pump only runs for a couple seconds so it's got to be getting up to pressure! I'm also thinking maybe I do have a bad cam sensor. If the crank sensor runs the injectors up to 400 RPM's maybe it's dying out when it switches over to the cam sensor. I'm going to order a new one and try it.

 

[bobbywalter]

Don't stop now.

 

[bobbywalter]

Might be leak off that's getting enough to cough....from prime cycle...and it is not firing the injectors.

 

[RonD]

Make sure he doesn't hold the throttle open all the way, WOT turns OFF the injectors

If there fuel at the rail?
press the pin and see if its fuel or air pressure

 

[Broosedamoose]

Make sure he doesn't hold the throttle open all the way, WOT turns OFF the injectors

If there fuel at the rail?
press the pin and see if its fuel or air pressure

He was only holding it half way. We checked pressure and still got 64 psi. Fuel sprays out of the schrader valve when pressed. I'm really hoping I got a bad cam sensor. It's got to be! I know for sure it's not PATS! I know for sure the wiring is good and right. Injectors read 16 ohms. There is fuel pressure at the injectors. There's really nothing else!

 

[Broosedamoose]

So if I have this correct, the PCM looks to PATS for an "OK to start" signal, that allows the fuel pump to run. When you turn the key the crank sensor controls the injectors until the engine gets to 400 RPM's and then the Cam Sensor takes over. So the only things involved with the fuel injectors are, of course the wires, the PCM, the PATS, the fuel pump, the crank sensor and the cam sensor? Unless you hold the throttle wide open and the TPS shuts off the injectors. Am I correct? It could also be a bad crank sensor.

 

[RonD]

Crank sensor also times spark, so you would have no spark and no injectors
So if it starts/fires by adding fuel manually then crank sensor is OK

 

[alwaysFlOoReD]

I had a similar problem one time. Turns out the little rubber gasket in the wiring connector was dry and acting like a return spring. It kept the connector apart just enough that it didn't make connection. A little dielectric grease solved that problem.

 

[decipha]

try holding the pedal to the floor while cranking to shut off the injectors. If you smell fuel its probably getting too much fuel and causing you issues.

 

[Broosedamoose]

Finally got it figured out! Bad injector! We pulled off the plenum and went thru them one by one and found one reading 6 ohms. Disconnected it and she fired right up. Must have been throwing off the whole system! Oh what a sweet sound to finally hear it run. Sounds incredible with open headers! Been waiting a long time for this! Thanks for every ones help! This is a great community! I will keep posting once I get the new injector in and continue building.

 

[PetroleumJunkie412]

Finally got it figured out! Bad injector! We pulled off the plenum and went thru them one by one and found one reading 6 ohms. Disconnected it and she fired right up. Must have been throwing off the whole system! Oh what a sweet sound to finally hear it run. Sounds incredible with open headers! Been waiting a long time for this! Thanks for every ones help! This is a great community! I will keep posting once I get the new injector in and continue building.

ABOUT DAMN TIME!!

Congrats man!