advanced cams for retards

[Spliffotticle]

I'm not reading through a hundred topics to see if this has been covered... (Alex Trebek voice) A CPS must be oriented in THIS fashion when your camshaft advancement is 4*. Good luck (doo doo doo doo doo doo doo.....doo doo doo doo..DOO.DU Du du du


I am thinking about setting the CPS with the cam NOT advanced; and after securing it..... THEN advancing my cam. Is this retarded? Your friend, OBDII

P.S.
If you do not have OBDII, NO DISTRIBUTOR, and an
advanced cam then your input is likely irrelevant

[IH 392]

The CPS doesn't have squat to do with the cam, it NEEDS to be timed to the crank, find TDC#1 set the distributor and lock it down, AFTER your done messing with the cam.

[Spliffotticle]

Now see, that's what I thought before I could not hold down a measly 9.4 DCR. I know it seems a bit high, and maybe it is. But am I to believe that it will fall on it's face taking off, have a window of power, then cut in & out like fuel starvation ( 24#/hr on stock regulator = rich, not lean {http://www.gtsparkplugs.com/InjectorSizeCalc.html} )or poor timing all because of 9.4? According to my understanding I should be able to just blow the engine if I have too much DCR & boost. I'm running o2 up & down with no related faults. TPS fault but that's not in control of enough to cause the symptoms I have, especially after varying it's position to check different perspectives. That will likely always fault because of my 4" throttle bore and the new ratio of air entering. I am almost certain that any jeep will run a default integer with the TPS disconnected and the driver would likely notice nothing but poor milage. There is something here that only someone with an advanced cam, no distributor, and a CMP can reveal to me. Before anyone says it... THE CMP DOES AFFECT SPARK TIMING. I HAVE VERIFIED THIS WITH A TIMING LIGHT RIGGED TO MY COIL RAIL. VIEW HERE: http://www.jeepstrokers.com/forum/viewt ... =26&t=2475 FOR FURTHER DETAILS. Sorry I kept calling it a CPS or CKP

[SilverXJ]

x2. CPS = crank position sensor.

If you are talking of the cam sensor CMP in the distributor then it only controls the indexing of the fuel injectors. Install it as stock. As has been covered on many Jeep forums and this one (if you searched) the distributor does not control the timing. Install it as you would on a stock engine.

[SilverXJ]

TPS fault but that's not in control of enough to cause the symptoms I have, especially after varying it's position to check different perspectives.

Try fixing that as the TPS contributes a lot to the EFI system.

[SilverXJ]

Also, when adjusting timing on a car with an adjustable distributor you watch the crank for the degrees, not the cam. The timing is adjusted around TDC on the crank, not on the anything on the cam.

[Spliffotticle]

CMP (for all you in the know) sorry for the confusion. However I hate to be the piss in your cheerios but as I stated I have already VERIFIED that the CMP CLEARLY affects spark timing and you can verify this too by taking a wire from your #1 plug top to another spark plug grounded, attatch a timing light, and adjust the CMP and the SPARK timing will change irradically. For further details see my last post. Also, are either of you running an advanced cam with a CMP instead of a dizzy? Because that would be killer and I would have some hard evidence.

[4.whoa]

X2 on the TPS. That's probably why you have a "window of power"

Also the sensor in the dizzy does the same as it does in yours. It just doesn't ALSO deliver / disperse spark.

[Spliffotticle]

Also, when adjusting timing on a car with an adjustable distributor you watch the crank for the degrees, not the cam. The timing is adjusted around TDC on the crank, not on the anything on the cam.

I knew that. Sorry if I was implying other things with my poor terminology.

[Spliffotticle]

TPS fault but that's not in control of enough to cause the symptoms I have, especially after varying it's position to check different perspectives.

Try fixing that as the TPS contributes a lot to the EFI system.

Ideally I would prefer to fix this. However, I welded a larger flange to my intake & integrated my IAC into the throttle. My throttle is so big that the air flow it allows to pass in the gaps made it idle 2500rpm. I had to paint the inside of the throttle to get an adequate seal & the IAC hole is quite a bit smaller than before (due to exessive idle). In retrospect.... I probably would have been just as well with the 3" since my intercooler & piping is 3"... . . ... . but I have excessive propulsion disorder.

[SilverXJ]

However I hate to be the piss in your cheerios but as I stated I have already VERIFIED that the CMP CLEARLY affects spark timing and you can verify this too by taking a wire from your #1 plug top to another spark plug grounded, attatch a timing light, and adjust the CMP and the SPARK timing will change irradically.

While it may effect spark as well as the injectors It only has one correct installation/indexing position.

Also, are either of you running an advanced cam with a CMP instead of a dizzy? Because that would be killer and I would have some hard evidence.

My cam is advanced 4* and no issue with injectors or timing. As I said before spark advance and retard is based on the crank/piston position, not on the cam position. For example "14* before Top Dead Center". That is on the piston position relative to the top of the cylinder, not to a cam lobe positions. That 14* is also crank degrees.

Ideally I would prefer to fix this.

As 4.whoa said, that is where your problem most likely is. The PCM uses the TPS information a lot. A faulty TPS will give the exact symptoms you describe. Sounds like you have a real mess there.

[Spliffotticle]

Your news....is bad. I have a mess indeed. I suppose I can mount up a regular intake to see if it runs fine but that is so MUCH WORK!!! : ( My header 180s right under the intake. makes the bolts difficult. I will be very happy if someone has an easy button I can use. I will go to some lengths to mess with the tps I see what develops. I imagine that it will have to read wot as soon as the throttle peeps open. Anyone know the rules on custom intakes???

[Jeep's Jake]

Lol Easy button... Take it for what it's worth... Square piece of steel, 60ish mm hole, and stock TB. Do your best and RTV the rest. It's not a proper solution, and you will probably have to disconnect your turbo plumbing, but at least you could get your engine running right and determine any build/timing/sensor problems before you take on the boost. Without removing your manifold. If everything checks out, I'd work on the TB from there. It's just a thought....

[SilverXJ]

I imagine that it will have to read wot as soon as the throttle peeps open.

Why?

[4.whoa]

Why are you using such a HUGE tb on such a small engine? 100mm is big even on most (street anyways) v8's. With F.I. a small tb matters even less.