Ben951S

*edit* Revamped original post

I believed my cold to warm idle was 14-16inhg.

Brought my car in for service to a recommended place, had a bunch of stuff done (alternator, J-boot replaced [said it was cracked], etc).

Now, cold start, I idle at 9-10inHG. I was starting to experience cold start problems (crank, but no start. Tach bounce every time). <1yr on Crank and Reference sensors, and I installed a new wiring harness for them. Always get tach bounce (crazy high tach bounce! Into 2k sometimes!). I replaced the DME Temp Sensor II. I thought this had fixed it, but this morning indicated otherwise (~45 degree morning).

Also getting bad mpg... was running rich (had chips, back at stock now though), but it still looks like bag mpg (will know next fill up).

I can still get up to 21inhg in gear coasting, but even warm idle now maxes out at 12inhg.

Running stock chips, 3bar fpr (new), most vacuum lines replaced, fabspeed 3'' exhaust and mild cam.

What should I be looking for? I inspected my work on the aftermarket gauge, do not see or feel any leaks from there.

Input welcome.

Since I cannot 100% confirm my previous #s (just being a big sissy), I am going to ask the shop to look for vacuum leaks (pressurize intake, whatever they want to do).

Darwantae951

Yes, your cam is probably why you are seeing lower vacuum numbers. It will also depend on the cam profile.

Ben951S

So if I can sustain ~21inhg under load (in gear coasting at 50mph in 4th or 5th), then I don't have a leak?

The only thing throwing me is 'I swear' I had ~14-16 when I first installed the gauge. But maybe I am not remembering correctly...

I was wondering if there was any way to tell... pressurize the intake and listen I suppose, but that is difficult for me to do.

Darwantae951

Call the cam manufacturer and see what they say. I have no experience with your car or set-up so I can't say if you have a leak or not.

How aggressive is the cam?

Ben951S

Ha,

Thanks Modded. You forced me to do something I've been wanting to do for a while. The cam is a

'951S PMR Spec Race Cam'

I called PMR (shop in NJ which made the invoice for the previous owner). They said they got it from EBS [Engine Builder Supply] and did not have any more information on it. So I called EBS. They were more helpful. Don is getting me the information and will get back to me.

So I will be getting a call back soon I hope (also provided email).

schip43

Is the low vacume casuing a problem? Power brakes come to mind, you could add a vacume canistor if that's the issue.

Ben951S

I have the factory vacuum reservoir, and brakes never hinted at not being boosted... Not feeling a problem. Idle is a little low but close to where it should be (at 925... should be 950-1000 I thought), doesn't hunt or stumble. Power feels very weak before boost comes on (3k+), which is what I would have thought the cam would help address, but I have no other 951 to compare it to.

minho78

You are in northern NJ. Mine just developed a cam tower leak. Once I get it fixed you can drive it and see the difference.

Ben951S

Thank you for the offer Min. I am up that way every couple of weeks (will be up Saturday, for example, ~07960).

I really should get more active in the PCA (I am in West Chester, PA, 19380), and make a few friends.

Ben951S

The specs should be as follows:

Duration: 256 degrees
Lift: .470"
Lobe center: Stock


So what does this do? Ha. I should post in my old thread...

schip43

It sounds normal to me! Off boost snap throttle response my little Toyota beats the crap out of my 951!

Now when full boost hits, it's game over! But it's not a very civilized ride! Max chipped...my understanding is the Rouge's AFM kit addresses some of these issues.

Crackership

I can say, without question, that the M-Tune pretty much fixes the issue completely. Off-boost performance is fantastic, and the transition is very smooth and early (with a k26/6)

Ben951S

I am strongly considering Rogue Tuning (AFM/A-Tune) once I install my Wideband...

kinglenario

as far as i know, the idle is supposed to be 840 +/- 40 with the ISV jumped when the engine is fully warm, then set to idle and get really hot for about 10 minutes or so.

schip43

Yep, my understanding exactly! He does a pretty job of explaining how the DME pulls the crap out of the timing and then ramps it back up!
Max chipped it's great for hauling *** but not to interested in doing the legal limit (60 out here) in 4th and don't even think about 5th!