[cspina]

Hey guys, I am running into a problem, I will get top end detonation no matter what I do to adjust my setting through my btc, base timing, and jr fmu. The car has been run from anywhere of 40 to 65 psi of static fuel pressure, and the timing has been adjusted from 10 degs to 16degs btdc, while using the knob at all different locations. I have a jr upgraded fuel pump, jr map controller, cam is advanced 10 degrees,one heat range colder plugs (gapped at .33), msd ignition and coil. I am wondering if I need to upgrade my injectors? Or the blower needs to be water injected, it will detonate at 6500 up to redline where the boost will creep up from 6psi to 8psi. Any suppgestings will be help full...I have played with my setting as mush as possible and just can't seem to get rid of this detonation.

 

[crx-sc]

ABSOLUTELY! you need to get some bigger injectors. I would recommend RC 310cc for you, unless you plan on going with Hondata or something like that later on. I had problems with my stock injectors at 6psi, they were maxed out big time. Yeah I am running high compression but still, if you are running 8psi I'd upgrade the injectors for sure.

 

[nov0798]

yea your injectors are failing.www.rceng.com

 

[GreekSpeed]

8psi is a lot to be running on stock pussy injectors...because they can only flow so much.....

 

[zcivic91]

are u sure ur runnig 10 degrees of advance on ur intake cam?? cuz thats also ten degrees of timing advance also..

why is the cam advanced that far...its easier to bend a valve that way... i say back it down to 3 or 4 degrees and then retard the dizzy so its at zero advance then use ur btm to adjust for the boost...

 

[cspina]

So we all think it is the injectors, would a safc be able to tune out the extra fuel during boost and idle if I stick with the jr fmu? Or do I have to pick up a car tech unit and adjustable fpr?

 

[crx-sc]

You should just be able to use the safc to lean out the idle mixture slightly. What fuel pressure are you running at idle? I have an adjustable regulator to set the idle fuel pressure (mine is about 36 psi), and I just use the jackson regulator set the way it came. My safc is set to -5 at idle. I'd try the injectors with just the safc and if it runs too rich then you'll have to get an adjustable fpr to drop the pressure at idle slightly.

 

[cspina]

I am running just the jr fpr, no stock fpr, and it idles at 22 psi, so although I am getting lean idle cels now, it may be great with 310 injectors just enough...what do you think...

 

[crx-sc]

no stock fpr? why aren't you using it (out of curiosity)? 22 psi is way too lean, you should be in the 30's at least. What does your fuel pressure read under full boost? I think even with the 310's it will still run lean at idle.

 

[AcidLotus]

There is NO way you should have your intake cam advanced 10 degrees. You need to double check that, as that is probably your #1 problem right now.

 

[zcivic91]

the wat this guy has been running his motor...im surprised its not messed up yet...i mean dam a n/a motor would run like shit if it was like that let alone s/c

 

[cspina]

I think my cam timing gear has been installed wrong, it is probably off thats why my cam timing is able to be so far advanced?\

 

[zcivic91]

if its off by a tooth it will have a 10 degree difference..

 

[cspina]

That got to be it, bec as soon as I got it back like that I was questioning it, how much of a job is it to time a cam gear, or I guess just do a timing belt job?

 

[cspina]

UPDATE: Problems solved, topend detonation::::cause connection where vacc line meets BTC hard pipe was leaking!!!! Cam timing, it has to be off by one tooth, if I set it at zero on the cam timing marks, I can not even get 3 degrees of timing out of the car, even by advancing the distirbutor to max.

 

[AcidLotus]

UPDATE: Problems solved, topend detonation::::cause connection where vacc line meets BTC hard pipe was leaking!!!! Cam timing, it has to be off by one tooth, if I set it at zero on the cam timing marks, I can not even get 3 degrees of timing out of the car, even by advancing the distirbutor to max.

Good! I never would have guessed a vacuum/boost leak could cause top-end detonation, but *shrug*. It definetely sounds like your cam belt is off one tooth.