Looks like someone has done their homework in the catalog, parts bin
or wrecking yard and has found an OEM serpentine pulley that extends
less than the C4 OEM unit.

.

 

Doesn't the Buick V6 use a cam sensor?

I wonder if parts and ideas could be adapted from it to reduce the
amount of development.

Buick V6 cam trigger magnet
Buick timing cover & block

Some discussion about dialing in a Buick-based FAST system driven by
crank and cam sensors here on TurboBuick.com

.

 

Slalom,
Thanks for digging up the detail from EM on the integrated crank trigger. I will contact them on Monday to see if they will sell "parts" of the kit (i.e. just the pulley, or possibly the pulley and the crank trigger). I do not want the distributor or the coil, as I am definitely trying to dump the MSD IP distributor that I am running now.

Thanks again for locating this and providing intellectual details to keep this post going until a solution is found.

Aaron

 

SloRvette is the signal, I'm just the noise in the S/N equation here.
Thanks for putting up with the comments from the peanut gallery.

My lazy alter-ego wonders about using the distributer adapter for the
cam signal. While a front-mounted cam sensor eliminates/reduces cam
& oil pump induced scatter, it requires development. Taking a signal
at the rear from a dist seems like an easier path - but does this
just throw away the benefit of building the crank trigger since then
the ECM is taking its cue from a sensor subject to camshaft scatter.

.

 

Aaron, let us know what you find out..

I really want to switch to the Crank trigger in my 89, but will use the OEM ECM ( which I know can be done) then I will move to the Cam Sensor and LSx Coils with my eDIST

 

There's pretty much no benefit from running the cam sensor off the front of the cam. It starts the injector firing if you're in a sequential mode but even that is fairly trivial in regards to accuracy.

The needed accuracy is in the crank signal.

 

Any news back from EM?

.

 

Unfortunately, I have been really busy on other projects that have pulled me away from this one. Hopefully back on it on Friday.

But, while I have a bit of time, let me give my impressions of what happens when you start closing the spark plug gap. The latest set of plugs are set at 0.029". The car starts and immediately wants to die. It was doing this at 0.032" gap as well, but it is getting worse at 0.029". You have to keep "popping" the accellerator to keep it running (kind of like the throttle / accelerator pump on an old Holley carb) until the car is up to ~160°F. Initially, I thought something had changed in the tune, so I worked for quite some time, and even cracked the throttle blades quite a bit to keep it running (set at ~1100 RPM vs the normal 870 RPM idle). But after it was warmed up, it would idle fine, but now at ~1500 RPM, so turn the throttle blades back closed (1 3/4 turns). Then it idles fine at 870 RPM.

It also has a stumble if you give it just a bit more throttle over cruise speed, until you get over about 2200 RPM. This also was not the case until the spark plug gaps got closed. It does pull to 6K, but I have not tried to go to 6400 RPM.

This has got me thinking... do coils go bad after some time? I have been running the same MSD Blaster II coil since about '93. Could that coil be dieing? Is there a way to check the coil operation?

If the consensus is that the coil may be dieing, what would be your choice as a replacement? I currently run an MSD6AL, MSD Inductive Pick-up distributor, MSD Blaster II coil, Jacobs 9mm ceramic boot plug wires with Accel sleeves, Autolite plugs, and timing advance controlled by FAST engine management.

Any / all thoughts are appreciated.
Aaron

p.s. Yes, I do still want to pursue the crank trigger and COP arrangement, but maybe a new coil would at least allow me to open the spark gap back a bit and return some of the driveability for the interim.

 

In the original post, the problem seemed to be lack of spark at 6K.
Problems at idle and low RPM where the SC is not raising cylinder
pressures suggests basic trouble-shooting of the ignition system
is in order. First principals.

Here is a silly pair of questions. What condition is the battery in
and what voltage do you see while at idle?

Oscilloscope traces would be interesting to watch.

IIRC, there used to be a procedure for checking the ohm reading
of the low tension/high tension circuits of an automotive coil. The
following may be relevent to the Blaster II
This next link has several suggestions - check the tips in paragraphs 5 & 6

- Ignition System Trouble Shooting - Les Bengtson

Have you observed the engine running in darkness for signs of leakage?

What condition are the wires & cap in? How is the compression.

 

We went on about this for a while back on TGO. I considered a CNP setup o n a boosted singleplane fbody, but then I scrapped the car for the vette.

I have a bunch of ford coil packs in my shop I was going to use. I think a northstar caddy dizzy was what we were going to use for a trigger because you could drive it with a '730 ECM.

Here is a posts to help:

http://www.thirdgen.org/techboard/di...?highlight=cnp

Try to stay away from a waste spark setup if possible. You don't wanna light the wrong cyl on a batch fire car.

-- Joe

 

Wow, that is an OLD post of mine. atleast I have been thinking about the switch for a few years.. LOL

 

Heh, you think thats old, I still have some old chase racing posts I can dig up from the late '90s.


-- Joe

 

LMAO, Chase Racing, man those ARE OLD!!

 

Let me start with what I can answer.

The idle and low RPM issue seems to be getting worse as I tighten up the plug gap. It almost seems like it takes a bit of heat in the engine to where the car will stay running. Could it be that the gap in the plugs has to get to a certain temp level, before it will perform properly? I have put the 0.036" plugs back in, and it idles fine with none of the low RPM sillyness. But it also looses spark at ~4600 RPM. That is the reason I have slowly been tightening the gap.

The battery was reading 12.6V when I started the car, and would idle at 13.9-14.2V. All seems to be in order. I don't have access to the equipment to do the trace, and I'm not sure I could get it to loaded RPM to duplicate the issue.

The above tests seem simple enough. I will check and return with comments. I have checked for leakage when dark, and at the present, I could not detect any spark jump. It is very obvious (on my car) when the spark plug wires are grounded, as the car will not run with hardly any load. The cap and rotor have less than 2K miles.

Thanks again for all of the feedback, it is most appreciated.

Aaron

 

The crank rotates twice for every cam/distributor revolution. A crank signal is only useful on a waste spark setup, otherwise the electronics won't know if your 180 out or not.

-- Joe

 

Post #19 - SloRvette discusses the interaction of a crank trigger
and a cam sync.

.

 

Roger that, my point is you can use just a cam sync, but you can't use just a crank sensor.

-- Joe

 

So you're trying to say that a COP ignition system will operate with only a cam sync ? You haven't made yourself very clear in what you're trying to say here.

 

Correct. All you really need is cam signal. A crank signal will only tell you it's on TDC of #1, but not of which stroke. Remember #1 goes to TDC twice on a 4 stroke engine.

We covered this a LOT over at TGO over the last few years. Bruce Plecan, along with a few others has run these setups using some borrowed northstar electronics from a caddy. Taking a small cap fbody dizzy and installing northstar electronics gets you both the cam + crank signal too, if you want to use an edist, or you can just use the cam signal and use fbody/lt1 electronics.

There is another kid on TGO that got this working using junkyard electronics and the $8F mask if I recall. (I think it was $8F, search TGO for distributorless, cnp, cop, and so on).

I had most of the parts collected to do it because I was having problems with the spark gap + the 15psi boost I was running on the 355. Didn't matter how much voltage I had, sometimes the spark just wouldn't jump the gap. But when the 355 blew up in '2004, I decided to build a big cam N/A motor so I haven't revisited the CNP stuff.


To summarize: CNP is good for three reasons:

1) No longer have quench time (recharge time) issues with a single coil, so you get a good hot spark every time.
2) No fluctuation in advance due to mechanical issues with the dizzy and tolerences
3) TRUE ABILITY TO ADVANCE BEYOND 38*


If you use a dizzy for your CAM + crank sync you might not benefit from
#2 as much as the tolerances in the dizzy might make it wobble.

And #3 means simply this. If the rotor is in the dead center of two ignition terminals, are you 45 degrees advanced, or 45 degrees retarded? Who knows which one is gonna light. Usually, about 38* is max you can advance even with a decent dizzy that has no "wobble".


-- Joe