Got a 93 Fd that has knock sensor problems at full boost 15psi.

Must get this fixed...Getting dogged by Mustangs https://www.nopistons.com/forums/pub..._DIR#>/sad.png





Have the following relivant mods.Rx6 Turbo. 750/1300 injectors,apex turbo and engine management, apex oversized intercooler, PFS engine



What in Hades is wrong with this thing...use to run fine.



My Mechanic believes its a boost issue. However it USE to run fine at 15 psi now under hard throttle at full boost in pukes.



All help greatly appreciated especially since nearest specialists are 500+ miles away. I live in W.V.



Thanks...

When was the last time you changed the plugs?



You are going to have to give more info into what it is doing.

If you have a power FC, it isn't your knock sensor that's causing you problems.

Man you need an ignition AMP BAD!

That's what it sounds like to me. You may have a weak leading coil.

ok more info...

yes I have a power FC and AVCR.



In second gear at between 4.5 and 5rpms (when I am starting to make the big numbers) https://www.nopistons.com/forums/pub..._DIR#>/sad.png under full boost fuel is cut OFF.





otherwise drives normally.

also I have two optima gell cells in the back

hope this helps explain better...

don't wanna just start swapping out parts https://www.nopistons.com/forums/pub...IR#>/angry.png

already got over 30k in my baby https://www.nopistons.com/forums/pub...1047683664.gif



thanks...

Erik Carr

XXXRacer

alright. What do you boost and what is your boost limiter set at? Also, what's your rev limiter set at?

Ok chuck the AVC-R hehe



No hummmm Jspec has a good idea. Did this just start happening or has it always been like this?



You have enough fuel there, I dont think its that. How does it run if you just run it up to 7000rpms or so, no boost?



I still think it might be a good Idea to check into the coils, ignitor (big bucks) or just an ingnition AMP, I cant believe you got away with those mods on a stock ingnition system, I mean I know its good, but in my small experience I have seen a lot of high RPM break-up on high boost loads on ported engines, or just anything besides twins, but HELL even with the twins hehe



OK or I could be dumb on american parts, whats and optima gell cell?



I have heard of Optima batterys...

yup thats right optima battery

use to have a monster sterio... https://www.nopistons.com/forums/pub...IR#>/happy.png

15pounds or 1 bar of boost max and to the best of my knowledge no boost creep.

I also have a little giggle gas in the back too, but I haven't used it since the big turbo and the power FC

rex limiter set as stock 7500rpm...

I cannot get any where near that before I get hit under full boost.

Long story short yes it just started happening out of the blue...

right after I blew my intake gaskets (I guess thats what they are called) where replaced my FD stopped doing full throttle pulls



as an aside what boost controller do use guys use since my arc-r is said to be not mighty https://www.nopistons.com/forums/pub...O_DIR#>/11.gif



thanks XXXRacer

what boost do you get to before it cuts out?