Max boost i run is ~8psi, but it will detonate intermitantly... meaning sometimes it will detonate in second gear at only 6 psi not even WOT, and other times i can blow through 3rd at 8psi and WOT.

My mods are a greddy intake, 2.5" dp, 3" main cat replacement pipe, stock y-pipe and mufflers. Smog pump removed, no ac or ps, and a stock TID.

How can i check for codes on an 88? (without buying the 1500 dollar mazda code checker of course...)

 

http://www.teamfc3s.org/info/article...odes/main.html

Right now, I suspect your pressure sensor. But I could be wrong.

 

Looks like im making me one of those as soon as i get the time. I dislike the fact that the ecu wont tell me when i have an error, i have to hook this funky gizmo to a check connector and hope something comes up... oh well

Why do you think its the pressure sensor? I was starting to think its the leading coil...

 

Well, the sensor will feed in more retard, as well as more fuel, during boost situations. A complete lack of spark wont necessarily cause detonation. Even a weak spark shouldnt necessarily cause it. I would *think* that it might cause a temporary rich condition. Course it is 130 in the morning, so I might just be talking nonsense...

 

By a lack of spark, do you mean when my leading coil is mis-firing?

This is my 1:30 in the morning theory, my leading coil is firing irradically (due to grounding problem, bad coil, or whatnot) and firing when its not supposed to, causing the detonation. Pressure sensor could be a possibility as well, i went to do the pressure sensor grounding a while back and i grounded the wrong stupid wire... is there a way to check the pressure sensor besides the way in the FSM? maybe its fried along with my leading coil

 

I find it odd that sometimes i will detonate under a lighter load at a lower psi, and sometimes not at all under WOT @ full *****....

 

I am finding this theory a bit hard to understand. The coil fires when its told to, and no other time (theoretically).

If the pressure sensor is bad, lets hope the ECU can pick it up...

 

Yes the coil is only fired when its told, but that would mean its getting an improper signal from somewhere because its mis-firing almost regularly.

How can i check the signals going to and from the ecu? If those signals check out (from the press. sensor, CAS, and the signals to my leading coil is ok) that would definately help me out as far as diagnosis

 

^ bump