PDM Cams Lumpy Idle?

[amoney]

I had the PDM Stage II (Intake 268 degrees duration, .441 valve list, Exhaust 272 degrees duration, .447 valve lift) SOHC cams installed and now my idle is lumpy. I experience frequent backfiring, and the engine cuts out when i brake hard. I have tried adjusting the idle higher with no luck. Gas mileage is awful now. I suppose I am running too rich. Perhaps the cam timing is off? Oh yea, I also have intake and flywheel installed. Thx in advance.

~Allen

[Aries]

Cam timing would be #1 on the list.Then tuning. You can't go and install cams like that without tuning the computer for it. The ECU will simply freak out and run the injectors at 100% all of the itme (which would be why the car cuts out/off when breaking hard as the RPM's drop.

[Silent Drifter]

I was thinking about gettin the same cams but for the DOHC so would you recommend sendin the ecu off to jet set an have them tune the ecu, or would you suggest something else?

[ADAMHU]

i had the stage 3 sohc cam...503 lift and 300 duration...

1= raise the idle up...just use the screw on the throttle body..

2= big cams have bad idles..mine 8 rolled at idle

3= my sohc computer did not do anything weird with the cam...it ran great top end...

[amoney]

Well, if my cam timing is off by a sprocket (i think that's +/- 10deg), would my car be running? I guess otherwise my topend is pretty good. I also hear and feel a lot more exhaust backpressure.

[Aries]

yes, the car would run, but run like crap.

[Yoden]

I was thinking about getting the PDM cam, did you have to get the cam towers milled? What was involed in that?

[amoney]

Basically, the cam towers have to be brought to a machine shop. They will know what to do with them. They just shave the spec'd amount off the top. I had them machine it when they did my valve job, so I'm not sure how much it cost.

[SSS]

yes, the car would run, but run like crap.

Define crap. I think mine's off a tooth, haven't had time to degree it yet, but still pulls hard to redline. Also, at a recent dyno day, i did 90.2kw at the wheels (120hp) with headwork and my 262/264deg cam, whilst a mate of mine with the same car but only a CAI, reprogrammed ecu and 2.5" catback with gutted cat convertor did 88.8kw at the wheels (119hp). His car had standard heads and standard cam.

[Aries]

ok, running like crap defined. LOL.Here we go.

A car runs like crap when you step on the brakes and the engine tries to die, when the motor refuses to hold a steady RPM at idle, when the car simply cannot idle without dying, when there is zero low end torque/pull due to the cam's overlap being set wrong (usually due to the cam gear being off 1 tooth), when the motor cannot be driven without backfiring (intake or exhaust).

That help?

[amoney]

Hmm... so you're saying my cam timing could be off a tooth and still pull hard to redline. Well then, might have to check that out. Anyone know the proper procedure for cam gear adjustments?

[sohc240]

Why have the towers milled? then your stuck with the cam. I'm saving up to get the real nissan adjustable rockers (ie racehead package) so you can change back to normal if you want. But then again if your going to spend that much $$ why go back!

[Yoden]

This is kind of a dumb question, but Im a former honda guy, is there any sort of adjustable cam gear for the KA24E? Would this help at all in tuning a reground cam?

[RedShred]

C404.H - Strong performer, with good midrange pull to redline. O.K. with automatics. Our strongest seller with the most smiles! {Intake 268 degrees duration, .441 valve list, Exhaust 272 degrees duration, .447 valve lift.} (note requires cam towers to be milled .030")

I'm using one that is very similiar to this with only the lift being like 450 or alittle more, I cannot remember...

I have a horrible idle as it is rather lumpy, but I have nearly 10:1 compression and port/polishing to go with it. My Ports were opened alittle more so it is breathing more. Other than that I dont have any stalling issues. My Car comes alive after 4000 rpm though... not real good for the street but fun anyway.

As for the Cam Index gear... Nismoparts.com has one. I have one but havent installed it yet. I figure I'm 2-3 degrees out and timed slightly retarded and it runs well there. *shrug* I'll eventually install the degree'ing gear but am not in a hurry.