as many of you know the 2.4 TC engine has a cam sensor on the end of it. now for 99% of people they could care less, but for some this is rather annoying. lets say you want to.. um run HO cams on your ported head. well too bad without some amount of fabbing. anyway i am wondering if there are ways to get rid of said sensor but not remove the system in place (if you unplug the sensor it goes to batch fire i think with cel). im wondering if the msd setup for the saturns would be adaptable to the 2.4 TC. if we can use the same ignition setup on the 2.4 that would be great! any thoughts.. please dont just say no your dumb, please provide a reason for your thoughts.
Sven you totally quarterloafed your computer..
my thinking is this
- 2.4 uses a sensor on the cam itself to trigger cam sync signal
- older saturns use the nifty compression on chamber 4 jobby to grab sync signal
- if the interface to the pcm is the same (i.e. voltages and such) then why cant the saturn system be adapted to the 2.4TC. this would allow the cam sensor to be disconnected and still run the stock pcm. as well as open up a bunch of toys!
i am not saying in any way that i am correct and that this will work. this is the logic i am trying to portray. if there are errors in my logic can you please point them out in a civil manner.
just thought id clarify since my 1st post made no sense when i re-read it. lol
Sven you totally quarterloafed your computer..
yeah, i would also like to know...
Bueller.. Bueller.. Bueller..
</Ferris Bueller's Day Off (1986) refference>
Sven you totally quarterloafed your computer..
Actually I do not see why not. I mean as long as the voltages and resistance is the same and the way the computer reads is the same then it should work. Of course I amy be wrong also, and that would make two of us. Just for clarification the 2.4 IS a wasted spark ingition isn't it?
msd can be wired into the 2.4 without any additional parts no need for cam sensor mods the sci ignition is also not for GM DIS engines, it wont work
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
what im trying to do is use the msd cam sync jobby to mimic the saturn cam sync setup and run it on a stock 2.4 pcm. that way you wont need a sensor on the cam itself. this is rather useful for several different reasons.
the major question is whether the signal for saturns cam sync and the signal for the 2.4's cam sync are similar to the pcm. this i dont know, hense the post..
i know the dis-2 works fine on the 2.4, thats not really the topic at hand here..
i bet some peope would like HO cams and adj cam gears on their 2.4, wouldnt they? also there are other things this will help.
Sven you totally quarterloafed your computer..
Try e-mailing Todd Miller (protomec) if anyone will have a clue I'd say it would be him... BTW let me know what you find out
...
"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
The 2.4 Cam signal is a 12v. square wave form that is high (12v) for 360 degrees of crank rotation (firing #1) and low (0v) for the next 360 (firing #4).
I am not an expert on the MSD unit, so I called them. According to them, it generates a 5v square wave form that according to the phone tech, is 50% on and 50% off.
The 2.4 PCM may be perfectly happy with 5v. It is only looking for a large than a specific programmed change in voltage, and the value is usually 2.5 volts. So its likely it would work. If not, a really simple $0.10 transistor circuit could be built to translate it to 12v.
The only other info I can get is the "50" number. Originally the tech said 50 degrees (actually he 1st said 20 degrees), but later changed it to 50%. 50% would mean 360 degrees of rotation which would be exactly perfect.
50 degrees on the other hand is way to short, BUT that doesn't mean the PCM wouldn't be able to use it either, that part is only going to have to be trial and error. It is equally as likely that the PCM would accept the shorter signal as it is that it wouldn't.
But for only $50, it seems to be well worth trying.
sig not found
protomec wrote:The 2.4 Cam signal is a 12v. square wave form that is high (12v) for 360 degrees of crank rotation (firing #1) and low (0v) for the next 360 (firing #4).
I am not an expert on the MSD unit, so I called them. According to them, it generates a 5v square wave form that according to the phone tech, is 50% on and 50% off.
The 2.4 PCM may be perfectly happy with 5v. It is only looking for a large than a specific programmed change in voltage, and the value is usually 2.5 volts. So its likely it would work. If not, a really simple $0.10 transistor circuit could be built to translate it to 12v.
The only other info I can get is the "50" number. Originally the tech said 50 degrees (actually he 1st said 20 degrees), but later changed it to 50%. 50% would mean 360 degrees of rotation which would be exactly perfect.
50 degrees on the other hand is way to short, BUT that doesn't mean the PCM wouldn't be able to use it either, that part is only going to have to be trial and error. It is equally as likely that the PCM would accept the shorter signal as it is that it wouldn't.
But for only $50, it seems to be well worth trying.
this is where i say you are the man! great info!
very cool.. i can be an ohm's law wielding, radio shack charge carding, burning my finger soldering, nerd! i like the sound of this..
Sven you totally quarterloafed your computer..
oh ok i see what you mean so your wanting to keep the pcm happy since you wouldnt be using the stock cam sensor, well I can see how this could work, the msd 8914 part hooks with 5 wires and it determines when the 4th plug wire is under load this tells the pcm whats going on
5 wires on the MSD 8914 Camsync part
Black - ground it
Red - MSD 12V power
White - splice into solid white wire on msd harness
Brown - you need to wrap this around the 4th plug wire, not this will work with stock spark plug boots its important to shave off about 3 inches of the insoluation on the wire and then wrap it with heat shrink or tape so the bare metal dont touch anything, otherwise just wrap around the 4th plug wire and do the same if using plug wires
Brown with white -, there should be a brown with white stripe wire coming into the ICM from the PCM you will need to cut this, ICM side isnt hooked to anything now and the brown and white wire from the msd part is hooked in instead, or because the 2.4 uses the sensor the wire on the sensor that goes into the pcm would be cut and the msd connected in its place as the new signal to the PCM
This works on an ecotec but I'm not sure how similar the camsync or igntion system is on the 2.4, I have limited knowledge of that motor but this might work, worst thing that will happen is the motor wont start or you will get the P0340 code
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
[quote=97cavie24ls(JDM&00s/c sedans™)]try it and let us know
yes now i just need a cavalier again.. a tree squished mine..
Sven you totally quarterloafed your computer..
ouch !!!!!!!!!!!!!!!!!!!!!!!!!!!!
not good
yeah it sucks. the culprit is in my reg.. a rotten tree.. bad wind.. and my luck. also the owner of the tree had billy bob's insurance so.. yeah i got screwed.
anyway now im looking into performance options and planning a best performance/$ j-body build.. a bunch still hangs on HPTuners though. i would be more than happy to help someone in the sw chi-town burbs if they wanna try this.
Sven you totally quarterloafed your computer..
Great idea, and awsome footwork on Todd's part, for making the phone call. I might be willing to give this a try, once my engine is back togather. My cam already has the sensor pad on it (thanks Todd and Brandon) but if this works, I might use it if I step up to the HO intake cam.
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
did anyone get this to work ? ? ? ? ?
Generally it's the change in signal state which triggers an event within the pcm, not the duration of the high/low signal.
FYI the Ecotec engine uses an OEM ignition module which generates a cam sensor signal. It's pretty cool, they actually determine which cylinder is on the compression stroke by monitoring current through the ignition secondaries. I found an article several months ago which described it (is that the link above??).
I'd expect anything which generated a cam pulse could be used, provided the timing of the pulse is close to what the pcm expects.
-->Slow
im still looking for a cav.. so no i have not tried it yet. if my cav is a 2.4 (prolly not going to be) i will def do this. i think at worst, you will need to solder up a black box if its picky about voltages, but like slows said it prolly wont be. cam swap away
Sven you totally quarterloafed your computer..
