Timing hungry ca18det

[bentvalves]

Hi all,

Im having a serious issue where I cant seem to establish 15dbtdcwithout the CAS being fully advanced in its range of motion. Thiswould normally point toward mechanical timing being out, but thatlead has been exhausted 10 fold....no doubt in my mind.

The timing gun will tell me 15 btdc idling, but driving the cartells me otherwise. Power is flat, boost cannot be controlled,EGT's absolutely soar, manifold/turbo glow lava red after a throughgear jaunt. It is obvious to me that timing is so shallow, unburntfuel is getting into the exhaust.

With that being said, I began to advance timing globally in 2 degreeincrements with PFC. I was able to safely add 15 degrees, no knock, lowerEGT's, much much faster car.

Well now it wants more timing, after driving it for a day or two itbegan to feel flat again and peak water temps were up a bit after apull (EGT probe previously melted, waiting for other )So shallow ignition timing came to mind again, and slowlywalking it up in 2 degree incrememts like before, I netted goodresults again.

WTF this engine is really starting to get the best of me, my handsare battered, my body is tired, my mind is going in circles, and Ineed to get back into a healthy sleep pattern.

anyone?

GregNew Hampshire

Sounds like the timing is "walking" backwards, yea?
Modified by ks13 at 10:20 PM 10/22/2007

[Buddyworm]

Could be a long shot: The key in the cam where the CAS slots in may be broken? The sensor shaft slipping slightly every time you drive is the only thing that I can think of that would force you to continually advance the timing like that.

[kapower06]

I would check to make sure that the CAS is not broken, or the splines are worn like mentioned above. Also check to make sure that the memory is holding correctly in the PFC. Or ditch the PFC and factory harness+sensors for $1600 or so and buy a standalone....

[r34 gtr]

For like $350 you could megasquirt that bish and use a not-as-sketchy-as-yours ford ignition system. Nothing against the nissan system, just yours.

[float_6969]

As others have said, it's probably the spline in the exhaust cam spinning. You'll probably need a new CAS and a new exhaust cam.

[bentvalves]

tried 3 different CAS's

they are new tomei cams, keyway thourougly inspected and is fine.

Besides, if the keyway was busted the car wouldnt even be running. It starts and runs, and when I advance timing in the map it recognizes this and pulls like a train.

I think I may have a bad ECU perhaps.

[bentvalves]

Im going to try a different ignitor from a q45 and see if that works.

Its coming with pigtails, but I was wondering where I could get some information on wiring it into my jap spec s13?

[Buddyworm]

I can't see the ignitor being the problem. It only amplifies the signal sent by the ECU. My money is on the PFC or, seeing as they're aftermarket cams, the adjustable gears.

[bentvalves]

adjustable gears removed, problem still persists.

Ignitor was right next to 1300 plus celcius radiant temps.

My money is on that ***** being cooked.

Someone in the datalogit user group had an identical problem come down to a badly grounded ignitor.

[dash]

u sure your crank pulley keyway slot not worn/elongated and have the pulley slopping around - it will vary your timing mark/reading.I had a bad case on one motor. Someone most likely didn't torque the big pulley bolt properly.

[bentvalves]

yea everything mechanical is 100%

its got to be a faulty ECU, or something electrical somewhere.

uuuuuuuugggh wtf did I do!

[bentvalves]

bump for Dee

base timing NEVER stays constant.

what would cause this?

[float_6969]

How do you know the keyway in the cam hasn't turned? I know they're new, but that doesn't mean that they can't be screwed up.

[bentvalves]

because its been inspected thouroughly, and MBT (minimum best timing) Is different every day. BASE timing is absolutley positively not staying constant.

**as stated in the FC datalogti user group and the EFI tuning tips forum, I am offereing a reward via paypal to whomever helps me diagnose this problem**

[bentvalves]

ok folks seems that the problem this ENTIRE time has been the abscense of a ground strap from head to chassis.

we'll see what happens over the next week and I'll update.

[roplusbee]

Any update on the nature of the issue? I have been hanging on for a good minute wondering if it has been resolved.

[TD or Not TD]

i would too like to know if it has been resolved.

and i didnt know the ignitor had to be grounded??

adjustable gears removed, problem still persists. Ignitor was right next to 1300 plus celcius radiant temps.

My money is on that ***** being cooked.

Someone in the datalogit user group had an identical problem come down to a badly grounded ignitor.

[float_6969]

Guys, EVERYTHING needs grounded. If you think grounding isn't important, put a grounding kit on your car and you'll see how much smoother it runs. The ECU gets cleaner signals and can therefore operate the car more effectively.

I can tell you from experience that 70% of all of the electrical problems I've ever fixed have been grounding related.

[roplusbee]

You just motivated me to purchase the grounging kit that I was looking at for the last 6 months, thinking "do I really need this or just want it". Thanks

[TD or Not TD]

roplusbee, what kit exactly are you looking at?

[float_6969]

I know I kinda started it, but start a new thread please. I don't want to get this anymore off topic than it is.

Thanks guys.

[bentvalves]

sadly the problem still persists.

snow will be flying soon though and its time to pull the motor to finish this thing 100% this winter.

to bad I wasnt able to resolve this issue, I still did however get to sample 300 whp so in all im happy.

[float_6969]

Isn't it retarded how fast an S13 chassis w/that kind of power is?

It'll beat up on most of what you'd run into out there.

[bentvalves]

Yes its great, so much fun, so easy to be stupid, so easy to kill yourself, so easy to run from po's, so easy to outrun anything you come across, you really have many options when you set out for a cruise.

my car weighs 2500lbs with me in it