EFI Cutting out at 3500rpms

[blazinchuck]

one other note..as i was testing to see what was getting constant 12v or not, i noticed none of the wires i was looking at had any voltage until i began starting. im wondering if this might be a reason for my long start ups? my buddys 5.0 starts right up! mine takes as long a carb needing the choke.


also, why is everyone having to cut that wire? why wouldnt that wire be getting the start 12v that it should? is this something the harness guys are doing or is this being caused by dropping certain things for these stand alone systems?

i love the motor now that it comes alive, just wish I could get it to start faster...thanks,Chuck

 

[IFLYHOOKS]

I think it is an issue with the harness guys, but I also need to trace that start wire from the TFI and find out where it is connected before I throw a stone. The diagram shows both wires going to the ignition switch, the 4th one down should be constant 12v as soon as I turn the key on, the third down (which we cut) should only have power when I turn the key to start. Is it possible your 4th wire is connected to the wrong post? I can't say for sure that is what causes your long start issue, but my engine fires right up and I have constant 12v on the 4th wire as soon as I turn the key on.

Whose harness are you running? Scott

 

[blazinchuck]

hhmmm...ok. when i get off work, ill check it out when i get home. im pretty sure i checked the 2nd,3rd,and 4th wire from the top and none had power until i began starting..then they all had constant 12v. im really glad i saw your post...i was gonna start throwing money at it for parts and electronics...glad i didnt waste that time or money. i was really think the HP pump was dropping pressure which was causing the 3200 thing.

 

[IFLYHOOKS]

hhmmm...ok. when i get off work, ill check it out when i get home. im pretty sure i checked the 2nd,3rd,and 4th wire from the top and none had power until i began starting..then they all had constant 12v. im really glad i saw your post...i was gonna start throwing money at it for parts and electronics...glad i didnt waste that time or money. i was really think the HP pump was dropping pressure which was causing the 3200 thing.

I was about to do the same thing, in fact, I did get another Dizzy from the Pull-a-part, but it obviously had no effect. I did about every Google search you can think of before I finally found the post on Pirates. Every Mustang forum and ours, everyone had the same thought process, must be the Dizzy, the fuel pump psi, etc. Who'd a thunk one wire that should only be start 12v could cause so much trouble? Scott

 

[ejdearma]

I bought a harness from this guy also and it was defective, out $335.00. I had to order a Ron Francis harness.

 

[KyleQ]

I know its an old post but my Bronco is doing the same thing - I've replaced some items as a maintenance requirement, but I don't want to throw money at this until it works. I've thought I ran into this issue before and fixed it, but it was late and night and I'm not sure.

I'm going to go out and turn the ignition on, probe the 3rd wire down and see what I've got.

No dice - no voltage when ignition on and 12v when cranking. Either my timing moved (as I couldn't even get the plug off due to it hitting the poster steering pump connector) or I'm back to my pip failure or a pin 30/46 issue.