Need Wiring Help

[Jeff Rand]

I am working on a stage 2 car that has an XFI. The number one injector is not being energized. I changed injectors and checked the new Casper's injector wiring harness as well as trace the #1 injector wire back from the female plug in the engine compartment back to the stock connector at the Casper's interface box. This all checked out (I had continuity). I was looking at the pin readouts on the XFI and was not sure which one corresponded to the #1 injector. Any help would be appreciated.
Thanks,
Jeff

 

[DR BOOST]

is there 12 volts at the #1 inj plug? the computer pulses the ground not the +

 

[HighPSI]

Pretty sure it's D9. Make sure the program has the correct number of cylinders and the cam sync is correct.

 

[Jeff Rand]

is there 12 volts at the #1 inj plug? the computer pulses the ground not the +

I will check it out tonight.
Thanks,
Jeff

 

[Jeff Rand]

I do have 16v ( it is a 16v system) to #1 injector. The XFI is configured for 6 cylinders. Firing order is 612345. The XFI has been on the car for about one year, so this a new problem. I just rebuilt the motor and after the first short test run (bringing up the boost to about 15#'s) the engine started to run like I had a spark plug wire crossed (not quite that bad). I decided to check compression and when I pulled the #1 spark plug it was as clean.
Jeff

 

[HighPSI]

Firing order is 165432. Verify the cam sync is correct in the Firing Order Sync screen. Do you have a noid light to verify injector pulsewidth?

 

[Jeff Rand]

Firing order is 165432. Verify the cam sync is correct in the Firing Order Sync screen. Do you have a noid light to verify injector pulsewidth?

Cal,
I was in a rush this morning and took down the wrong firing order. It is 165432 as you stated. I do not have a noid light.
Jeff

 

[HighPSI]

Cam sync precedes cylinder "6" ?

 

[Jeff Rand]

Cam sync precedes cylinder "6" ?

Cal, yes that is the way it is set up. This problem happened after the engine rebuild on my first test drive when I first got into boost (just enough to break the tires loose) then it started running bad. When I got it home all the spark plugs looked like they had been firing. I checked the compression and replaced the plugs with new NGK's. I did check #1 spark plug to see if it would fire and it does. I am thinking of pulling the XFI box out of my car and installing it in this one. It will be a PITA to do because of the locations of the boxes but it might tell me if I have a bad driver. I first want to get a noid light and check the signal.
Jeff

 

[HighPSI]

If you can't get a noid light, swap the injector plug with #3 (if it will reach) and see if the problem moves

 

[Jeff Rand]

If you can't get a noid light, swap the injector plug with #3 (if it will reach) and see if the problem moves

Switched the injector plug and the problem moved. I also noticed that the arrow on the fuel pressure gauge (on the fuel rail ) is not stable (noticed this a few days ago but forgot to mention it). Also pulled the passenger seat to inspect the XFI and the wiring. It all looked good. All the lights on the XRF box (showing the injectors) were also working.
Jeff

 

[HighPSI]

It's pointing to a bad injector driver, which is a pretty rare failure in these boxes. Do you need me to send you a loaner box to see if the problem is fixed or do you have another box you can swap in? If the XFI was purchased through me than I need to get you an RMA number. Was it?

 

[Jeff Rand]

Cal,
I am getting another loaner box today (from Ralph's brother) The XFI was purchased through you. Lets see what happens tonight.
If I had a bad driver wouldn't the lights on the box showing the injectors firing indicate a problem.
Jeff

 

[HighPSI]

If I had a bad driver wouldn't the lights on the box showing the injectors firing indicate a problem.
Jeff

Usually, that's why this is such an odd problem. Let me know if the new box fixes it.

 

[Otto J]

IF the driver is bad the injector LED wont light.
You said it has continuity from the xfi to the injector plug?
maybe tug on the wire at the XFI connector,ive seen on some where
the wire was crimped so hard it actually broke at the pin.

 

[Jeff Rand]

I decided to change the injector harness (I had a new Casper's harness on this new motor). So I put the original harness and XFI back on the car. I also picked up a noid light kit from Harbor Freight and tested number one injector wire. It tested good! I ran the engine tonight and all seems to be good. I did a bench ohm test on the Casper's injector harness and it tested OK even with a lot of tugging on the wires. So could it be a compatibility issue with the Casper's female connector and the male plug on the main harness. I am still nervous because something leaned out this engine and melted #5 and 6 pistons. Unfortunately the owner did not data log the run but I never found what I thought was the problem. I was wondering if under load the injector driver could go bad. I will take the car out on the street tomorrow and do some controlled blasts.
Jeff

 

[rafael vasquez]

control blasting????

i'm with you jeff i'd wish i knew what melted my pistons,
I do not wish for it to happen again!!!!

I hope you find the problem...

Jeff thanx again for all the work you have done to my limited, I know it's been a BIG PAIN IN THE A$$,

thanx for every ones input and help!!!
LOVE THE BUICK COMMUNITY!!!!!!!!!!

 

[Jeff Rand]

control blasting????

i'm with you jeff i'd wish i knew what melted my pistons,
I do not wish for it to happen again!!!!

I hope you find the problem...

Jeff thanx again for all the work you have done to my limited, I know it's been a BIG PAIN IN THE A$$,

thanx for every ones input and help!!!
LOVE THE BUICK COMMUNITY!!!!!!!!!!

It will all be forgotten once we get that nine second pass.
Jeff

 

[Jeff Rand]

Well after doing my best CSI impression I found the problem with the number one injector. See picture:

 

[Boost231]

wow, glad you found the problem. send it back to caspers and see what they say