WHAT'S LIMITING MY POWER?!?!

I heard if you put a bulb between your teeth and tip of tongue on the end it will absorb the shock from the plug wire. Never tried this myself. Actually just made it up but it sounds cool.
Sorry

 

That's solid Darwin Award territory

 

I hope no one attempts this but that award goes out too often.....we will see.

 

@ Wildcat

THIS is your key diagnostic right here. In fact it is the ONLY piece of actual hard data you have so far --- everything else is hypothesis and subjective observation.

It is also very telling of what the basic problem is. The only way I can think of that the carbs are sucking more air than they are supposed to (on a stock engine) is if the valve timing is off. Perhaps someone else can suggest another possible cause ?

It is very easy to check that the cams are set, at least close to, where they should be by turning the crankshaft by hand to #1 TDC and checking whether the inspection/assembly marks on the cams & bearing caps are aligned --- I would suggest you do that before you chase anything else.

As I stated a few pages ago, something "basic" is off with your engine. And, by basic, I mean something fundamental to any engine setup --- valve timing fits that category

 

Justin, crazy stuff man

I know you have repeatedly confirmed that you had a world class chief installer installing your XDI-ignition
I don`t want to doubt that, but even super heroes fail from time to time

so since you seem to have too much time on your hand anyway,
here`s more food for thought :


1) verify crank sensor installation

correct alignment necessitates that the center of the sensor must be aligned with the trailing edge of the 11th tooth
after the two missing teeth when the engine is at TDC cyl. 1

the timing settings are solely dependent on the crank trigger installation angle -
if not installed correctly, values on the knobs will not represent correct ignition advance and timing will be far off ! (6 degrees per tooth)


2) verify correct order of ignition wires

a) firing orders

308 cylinder firing order: 1 5 3 7 4 8 2 6

XDI ignition coil firing order: A1-A2-B1-B2


to verify the correct order of your ignition wires, look at coil pack A1/B1 (rear bank)
and follow the wires clockwise starting with the wire directly next to the 4-pin xdi-connector
(for orientation: position the coil pack such that the 4-pin connector would plug in from "above" !)


b) coil pack A1/B1, rear bank, (4-pin connector from xdi pin 1,9,17,power)

coil A1

wire 1 - to cyl that fires 1st (this would be cyl 1)

wire 2 - to cyl that fires 5th (this would be cyl 4)


coil B1

wire 3 - to cyl that fires 3rd (this would be cyl 3)

wire 4 - to cyl that fires 7th (this would be cyl 2)



c) coil pack A2/B2, front bank, (4-pin connector from xdi pin 8,15,22,power)

coil A2

wire 1 - to cyl that fires 2nd (this would be cyl 5)

wire 2 - to cyl that fires 6th (this would be cyl 8)


coil B2

wire 3 - to cyl that fires 4th (this would be cyl 7)

wire 4 - to cyl that fires 8th (this would be cyl 6)



verifying in this case is best and easily done by YOURSELF instead of by the guys who did the installation in the first place
(maybe this helps, maybe the problem lies somewhere else ... at least time won`t be lost)

good hunting !

.

 

… after pulling the plug wires right? After.

 

WELL??? It's been over 24 hours. Do you have a life or something?

 

Sorry to hear it and even though I don't know you or her it's good that she's ok.

And ignore the insulated pliers, it will make a better story in 10 years.

 

So you performed half the test?

It's ALL of the plug wires and then I will be quiet and you will have eliminated several concerns.

How's your Mum?

 

the xdi has a rpm limit cutoff- potentiometer knob on far right of timing control face of the chassis(box). choices are 4k, 6k, and 15k and up. easy to change with screwdriver - check that setting if too low that's your problem. 308 installation (V8) for the direct fire units (coils to spark plug wires) needs 2amps for the xdi control unit and 10 amps for the dfu"s(you should have 2). good luck, jon s p.s. electromotive unit is not very sophisticated but fairly reliable. mag pickup is the usual source of failure but if engine runs not the problem.

 

Oh no, it's just the way it was written it looked like you only pulled the front bank plugs. If you did all 8 and no change then many things are good! Keep plugging away at it!

 

That doesn't sound right. So the car stumbled with each plug being pulled on the rear bank but nothing happened when you pulled each wire on the front bank? Almost sounds like the front bank is doing nothing.

 

one more thing that can be easily confirmed before you dig any deeper:

open the frontplate of your xdi-ecu and verify the position of the 8 jumper switches -

for an 8cyl/4tach application they should be set like this:

.
Image Unavailable, Please Login

 

A few pages ago I did suggest disconnecting the front and rear bank coil pack in turn to see if any difference between front and rear. That way you know whether one whole bank is dead and can base further diagnosis on that.

From the new evidence it suggests one bank is in fact dead.

 

THAT IS EXACTLY RIGHT! My mistake on not reading what you wrote.

NOW you know that the front bank has problems,

AND you know it's not a particular cylinder,

AND the one thing you changed (well not you actually) is the IGNITION

AND your ignition system uses a separate coil/computer for each bank (Right?)

.. ya see where this is going…

Get the original system hooked back up, zip tie it to the firewall as a temp measurement , and drive the car!

;-)