Raised compression, now motor wants 20 deg spark advance to idle, whats with that?

Ray III · Sep 6, 2004

FINALLY got my car back together. While I was rebuilding the 2.3 I had .060" taken off the head which I figure raised my compression ratio from 9:1 to 9.7:1.

I got it started once yesterday then the starter took a dump so I didn't get around to tuning it till tonight

anyways I put the timing light on it and fired it up, it didn't want to run without you giving it gas, at factory spark advance of 10BTC it idled but it was really crappy and surging, I had to advance base timing all the way to 20 and it idles great...

something aint right here... You can't get 20BTC on a stock motor without pinging, yet you need it on a higher compression engine? WTF is going on here.

I can find no other marks on the balancer and besides I triple checked the alignment of all timing marks during assembly, so when the mark on the balancer points at TDC I am positive that #1 is at TDC. Spout connector was out. Wasn't getting confused with the timing light advance.

It revs up fast enough no load but when I took it for a test drive it kind of ran like dog****, maybe the knock sensor is making the computer retard timing? Then again it's a new motor and 4 month old gasoline. What do you guys think, am I nuts to think it's supposed to run with 20 degrees base?

bhuff30 · Sep 6, 2004

you pulled the spout connectors when you set the timing, right? Does it advance when you plug it back in?
It takes a little while for a fresh engine to break in. I never got my low end power back until I had 500 miles on my new engines.
If your problem isn't ignition timing, then it is cam timing. You need to double check all that.

bhuff30 · Sep 6, 2004

BTW, you are probably closer to 10:1. You may end up running 7-10* of timing once you get your mess sorted out.

Ray III · Sep 6, 2004

Yeah but I don't have a mess is the thing. Certainly not the first motor I rebuilt. The last motor I did that had timing belts, I didn't pay attention to timing marks and got the cams 180 off which was discovered AFTER it had been shoehorned into a FWD pos dodge... So you can be sure that I made absolutely certain timing belt is perfect, this time around.

Yes the spout was out...

Maybe later it will idle at a lower advance but I don't get how it even runs at that extreme.

If the car had a vaccuum leak would it want the timing advanced? Cuz like I said at around 10 deg it was surging at one point...

WELL at this point the computer hasn't even adjusted to the motor yet, so I'm just gonna drive it for a week, and figure out how to hook up the knock sensor to an LED so I can monitor that.

Bearded Forever · Sep 6, 2004

Wouldn't shortening the head with milling throw the timing marks off?

bhuff30 · Sep 6, 2004

Crovax said:
Wouldn't shortening the head with milling throw the timing marks off?

yeah, but not in a bad way. I calculated that milling it .100 retards the cam by 2*. That isn't much change, and considering that almost everyone here is running a stock cam, it will help them some.

TurboFlush · Sep 6, 2004

no it should not mess up the timing as, that sprocket would be the same regardless of shaving the head or not.

When you shave a head it will need a slightly diff timing adjustment. I cant remember which way though.
Dont feel bad, I shaved the head on my 2.0 and it also runs and idles goofy. then again I am using a EFI cam with a carb setup atached to the head. I got an adj. cam gear that I want to install and see what I can get it to do.

I think I need a better carb also, this POS I got now is a pain to tune. (vacume secondary).

one thing I do know is that it will be wanting more fuel and more air. so if any of those are restricted then you got problems.

I am going to bore a jet out and stick that in the secondary again, and rig the secondary so it will open when I step on the gas regardless of vacume. before it was pinging, so I think it wasnt getting enough fuel. now to find time to play with this.

****ty gas will fudge it to! it took me a tank or two to get the car to run better.

bhuff30 · Sep 6, 2004

I am seeing a theme here. Why is it that everyone that has milled their 2.3/2.0 has a ****ty idle?
I have 9.8:1 compression, and for the life of me, I can't get it to idle with more than 10 inhg. I can't find or hear any vacume leaks, and the ignition components have been replaced several times over. Ohh well... at least it doesn't shake like it used to.

Ray III · Sep 6, 2004

I was told that the amount of advance I had dialed in was gonna melt a hole through a piston whether it idled good or no. So I turned it back to 12. It surged like nuts for a bit and then smoothed out, it doesn't idle perfectly smooth but it is ok.

Figure the computer will get a bit more used to the motor anyways. Plus some fresh gas couldn't hurt. (Which is why I continued to drive the thing around for another 100 miles with a broken piston until I was almost empty, lol.)

Ray III · Sep 6, 2004

TurboFlush said:
no it should not mess up the timing as, that sprocket would be the same regardless of shaving the head or not.

I think the idea is that the distance between the sprockets is shortened and the timing belt is pretty accurately made to fit the stock distance so you would be a couple degrees off. But as was said it's hardly enough to affect how the motor runs.

When I put the belt on though the alignment of the marks looked just about perfect.

HyYoSilver · Sep 7, 2004

Ray, I'd get an adjustable cam sprocket and change the cam timing. Even if the cam is off only 2*, that translates into 4* of crank rotation. My guess is it's off even more than that. I'd try advancing the cam timing about 6* to start. It should then be so fast as to make ricers run home crying to their mamas....

351wcoupe · Sep 8, 2004

I was told that for every tooth your timing belt is off its 18* Maybe your belt is off a tooth and the 20* is compensating for that.

I don't care how many I've done its still a pain, at times, to get the marks lined up.

Ray III · Sep 8, 2004

The cam timing is correct. Period. Even if the cam was 2 degrees off and causing the motor to lose either high or low end power, it would show up as increased power at the other end. This thing has NO power.

100 miles on the motor, some increase in torque so far... it probably has about 90-100hp. I was looking for more like 120. Coolant temp is way too low -- 160 with a 195 t-stat. So I am thinking it has poor combustion for some reason. Not running rich though, according to plugs and I only burned less than 1/4 tank in 100 miles. Also the exhaust has a pretty mean growl where before it was just a tinny whine so cylinder pressure seems to be pretty high. Things I'm looking at are

- Computer may be pulling lots of timing cause of pinging picked up by knock sensor, try 89 octane or turn down timing more

- Dirty injectors, try some high detergent fuel

-EGR removed, but valve position sensor is still plugged in like it was before, I heard having the position sensor 1/2 in would make the engine run better

Touring23 · Sep 10, 2004

Ray, just curious which cam are you using?

I am seeing a theme here. Why is it that everyone that has milled their 2.3/2.0 has a ****ty idle?

MAP system? My MAF'd rig has no such issues. Let's see...lower vacuum at idle = higher load in table = extra fuel. If that is correct, 20* might be necessary to get the soggy mix to light off.

(edit: that would explain the low coolant temps, too).

Ray III · Sep 10, 2004

it's just the roller cam from the Ranger/91+ Mustang. Doesn't seem to have made two ****s of difference. Then again the motor keeps breaking the clutch loose on a fast shift (clutch was fine before) so maybe it was a LOT slower than I remember.

I put 89 octane in today and ran the piss out of it. Almost seemed to idle a bit better sometimes but really not much of any improvement. Disconnected knock sensor, drove around, no difference. So I don't think it was pinging at all. I'm going to advance timing again and see what it does.

I guess I'm gonna have to ask... what should I be setting the spark timing at? Clean new motor with I figure 9.7:1 compression and the roller cam. Right now it's at 12 BTC, factory spec is 10 but some people get it as high as 18 with stock compression?

TurboFlush · Sep 11, 2004

I think my mission if I have time tonight will be to put my cam gear on my car and see what that does. but what Ray III said is almost exactly the same as what mine is behaving like. I need to dig out my timing light also and see where it is. although I have better results road tunning the timing.
One of these days I will get around to it. I'll let yall know when I do.

Ray III · Sep 11, 2004

Put the timing light on it, well the computer was giving it 20 degrees advance anyways so I cranked it up to 20 base (spout out) then went for a drive, with knock sensor disconnected. No improvement. I even tried taping the EGR valve position sensor halfway in and all that did was lean it out. Set the timing at 16 and left it there, I'm lost.

I pried out the butt-plug in the timing cover to check the cam marks just to be certain that the belt didn't jump a tooth however unlikely. Marks line up perfect.

This is everything I've done to the car, and it has a choppy idle and maybe 100 hp, 110 at the VERY most:

-Ranger header and full 2-1/4" exhaust with Flowmaster muffler.
-5.0L air filter box and jimmy-rigged intake tube.
-0.060" off cylinder head.
-Ranger roller cam.
-Engine rebuild including 3 angle valve job.
-Cut back spark plug ground straps to unshroud spark (same gap).

What the hell is wrong????????????

Are there any sensors that would go bad and cut down output while the engine still runs good? New oxygen sensor and MAP sensor.

I noticed the Ranger cam has fatter lobes, would I need to advance cam timing for better results? I notice it STARTS to make power around 4500 RPM, hope I didn't make a Honda out of this thing

Is the stock intake posing enough restriction even to kill low end torque?

Touring23 · Sep 12, 2004

Three things come to mind:
*Check the IAT and ECT sensors, maybe one was missed or damaged during the install. Won't set a CEL, but will make the car run like poopy.
*Check for codes.
*Find a wideband O2 +/- dyno.
IMHO. Good luck.

Ray III · Sep 12, 2004

Good call on the air charge temp sensor. I did try to clean that thing in the parts washer when I had it apart and I have come to notice that when I start it in the morning the idle is smooth as silk but when the engine heats up the lumpy idle is there. I will replace that when I got some cash for it.

Codes are for EGR and the missing cooling fan that are in a landfill somewhere.

Plugs appear normal, COULD be very slightly rich but the way it runs doesn't make it likely.

Raised compression, now motor wants 20 deg spark advance to idle, whats with that?

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