i think i put my cam sensor in wrong

[Lbraucht]

my old one was making noise so put a new one in and i think it was in wrong i put it in just like the old one but i'm pretty sure the enigne was at TDC i was looking around and somebody posted saying it needs to 25# ATDC so i guess mine is wrong if he was right becasue i don't know i just put it in not to long ago and the car felt the same as it did before SLOW if i have it in wrong and the car does not have the right timeing i guess that would really slow the card down wouldn't it.
-Tim

 

[Black Car]

Here is the procedure from the gn/t-type site.

Cam Sensor Adjustment Procedure
1.
Measure on a piece of masking tape and mark it at 1.45" and tape it to the Balancer at 0 degrees.
2.
Bring #1 to TDC and then grab the intercooler fan and rotate the motor to your mark (25 degrees ATDC). This takes a
little patience and muscle. You can try bumping it with the starter, but I'm never very successful at that.
3.
Back probe the middle wire of the cam sensor (marked B and normally blue) with a voltmeter. Turn the key ON, but
leave the engine OFF.
4.
Loosen the sensor with a distributor wrench or a wobble socket and extension.
5.
Rotate the sensor full CLOCKWISE. The voltmeter should read 7.5+ volts.
6.
Slowly rotate the sensor COUNTER clockwise until the voltage drops.
7.
Secure the sensor at the instant the voltage drops.


The sensor is a hall effect device with a rotating metal ring that is driven from the front of the cam gear via a shaft (like a
distributor). This ring passes thru a grooved sensor molded into the sensor cap. The metal ring has a notch or window cut out
of it. When the window goes by the sensor, the voltage drops, which tells the ECM where #1 TDC is.

Jim Frankovich has done some measuring and calculating and has the following input:

20º = 1.160"
21º = 1.218"
22º = 1.276"
23º = 1.334"
24º = 1.392"
25º = 1.450"
30º = 1.740"
Every degree figures out to be about 0.058"

Several people have found that when running a bigger cam with advanced valve timing, it sometimes will help cure a popping or
sputtering symptom by advancing the cam sensor a few degrees. The above values give you an idea of what to shoot for.

 

[OneLethal87GN]

Some sort of gadget that shows when it's set correctly helps alot in this situation. I have the "cam tool" that alot of the vendors sell and it works pretty good. Do a search on www.gnttype.org and you'll find a few things about setting it correctly.

 

[WH1Driver]

I'm surprised it would even start if you didn't set it 25 degrees ahead. Especially if you set it at 0 degrees. I had a hell of a time with mine even following the above procedure. Mine was a fresh build though maybe thats a reason

 

[Lbraucht]

my engine was supposed to be rebuilt about 2000 miles ago when i bought the car than i noticed that it has all the orginal senors and everything else i guess the guy just did the eternals thanks guys that really helps out alot
-Tim

 

[tta1401]

Black Car:

Several people have found that when running a bigger cam with advanced valve timing, it sometimes will help cure a popping or
sputtering symptom by advancing the cam sensor a few degrees. The above values give you an idea of what to shoot for.

How big of a cam does it have to be? I am running a CC 212/212. I only advanced it a tad (1.47"). Would that be enough or do I have to do some expermenting? Just wondering.

TIA,

 

[Black Car]

Hi TTA1401,
The procedure that I posted cam from the gn/t-type site and not mine. My guess would be anything 220 or bigger.
You could always just try a few more degrees. The chart even gives the measurement you need to increase or decrease your timing on the cam sensor.

Gary

 

[rb68rr]

This may be a stupid question but I'm going to ask it anyway. If you set it 2 degrees off from the 25 degrees atdc will it make an 18 degree chip 20 degrees????? Or does that not have anything to do with your chip. Thanks, R.B.

 

[UNGN]

Originally posted by rb68rr
This may be a stupid question but I'm going to ask it anyway. If you set it 2 degrees off from the 25 degrees atdc will it make an 18 degree chip 20 degrees????? Or does that not have anything to do with your chip. Thanks, R.B.

Cam Sensor controls the fuel injector timing so, no it wouldn't effect the timing.

The crank sensor is where that comes from.

 

[DR. EVIL]

so that would prolly be why my car has horrible gas mileage right now with my bad cam sensor not correctly controlling the injector timing.... its running pig rich when I let off the pedal. you can hear it kind of lightly popping and "bubbling" when you let off.
Of course theres the bucking, "misfiring" and backfiring while you're driving after its hot, and when you unplug the cam sensor it stops....

 

[UNGN]

Originally posted by DR. EVIL
so that would prolly be why my car has horrible gas mileage right now with my bad cam sensor not correctly controlling the injector timing.... its running pig rich when I let off the pedal. you can hear it kind of lightly popping and "bubbling" when you let off.
Of course theres the bucking, "misfiring" and backfiring while you're driving after its hot, and when you unplug the cam sensor it stops....

That sounds like a 180 degree out cam sensor.

 

[striker_29]

The "cam sensor tool" comes from Caspers, best 25 bucks I have spent on my car I believe.

 

[redhotrod]

How big of a cam does it have to be? I am running a CC 212/212. I only advanced it a tad (1.47"). Would that be enough or do I have to do some expermenting? Just wondering.

Not completely positive, but doesn't Comp cams grind their camshafts 4* advanced? If so, I would think advancing the cam sensor .232" (.058"x4) more than stock.(24*+4*=28*)(1.392"+.232"=1.624") Be sure to make your mark on the passenger side of the timing mark!

Or does the stock camshaft have some advancement in it too?

 

[redhotrod]

This may be a stupid question but I'm going to ask it anyway. If you set it 2 degrees off from the 25 degrees atdc will it make an 18 degree chip 20 degrees????? Or does that not have anything to do with your chip. Thanks, R.B.

Another thing, would you want your fuel timing = to your ignition timing, or actually maybe a tad before to get the fuel in and ignite on time?

 

[boostcreep]

Yikes! Maybe you people should check out the 'other' board and do a search for ' Cam sensor and timing Q '. A little knowledge goes a long way.......

Nick

 

[scottyb]

Originally posted by boostcreep
Yikes! Maybe you people should check out the 'other' board and do a search for ' Cam sensor and timing Q '. A little knowledge goes a long way.......

Nick

I agree!

FWIW, I lost my timing gear last week. When I put it all back together, I ballparked the balancer mark while setting the sensor, and used a voltmeter. Ran like a champ on the first turn.

Long story short, the crank sensor determines both ignition and injector timing. The cam sensor only tells the ECM which rev is #1. All you need is for the cam sensor to be inside the #1 "window" of 6.

 

[Nick Micale]

Originally posted by Black Car
Here is the procedure from the gn/t-type site.

Cam Sensor Adjustment Procedure...........................
2. Bring #1 to TDC and then grab the intercooler fan and rotate the motor to your mark (25 degrees ATDC). This takes a
little patience and muscle. You can try bumping it with the starter, but I'm never very successful at that.
..........................................

Great info posted by Black Car, BUT, the engine MUST be on TDC [plus 25 deg.] on the compression stroke. If not, the cam sensor could be 180 degrees out.

To verify this, no. 1 spark plug must be removed, and the engine bumped over at the same time a finger is over the plug hole. [Need 2 people unless arms are VERY long!]

When compression is evident blowing through the hole, then set the balancer 25 deg. mark at 0 on the tab.

 

[tta1401]

Wow! This is an old thread. Well just to let y'all know, I stepped up from 42.5# inj to 50# inj and the so called "fishbite" went away and it went way away becasue it was pretty bad. Ran awesome!! I also put an extender chip in as well. Cam sensor position came out fine using the method from gnttype.org. Don't know if inj's/chip was the cure or I just rubbed a little magic when I changed those pieces out.