Re: Suspecting problems with Crane 700

["Dean W. Cains" <dwc@domain.elided>]

Hi Stefano:

First, the ATS wheels look great, and so does the rest of the car.

Second, I've had a Crane XR-3000 and LX-91 coil (very similar to your 
setup) on my '74 Spider for a bit more than a year of driving, maybe 5K 
miles.  I've never seen problems like you describe, and I couldn't be 
happier with the improvements over the stock system.  I did however install 
the optical trigger in a Bosch 041 disty, and that was one major pain in 
the ass, due to the tight quarters inside the Bosch.  Before the Bosch, I 
had the system in a Marelli S103BA, again with no trouble, and the install 
was much easier.

Checking the spark in the system is quite easy.  Position the crank on the 
engine so it's just before where the timing is set (i.e. 10 degrees BTDC, 
if your timing is set to 5 degrees BTDC).  Pull the coil wire out of the 
distributor and place the end near (1/4 inch) a good ground, like the cam 
cover.  With the ignition on, grab the rotor and turn it clockwise and 
watch for the spark.  The distributor shaft isn't really turning, just the 
top part with the advance mechanism.  With that coil, the spark should be 
pretty strong.

Your problem may be with what Crane calls "phasing" of the trigger 
assembly.  The trigger must be mounted very precisely, so that it fires 
when the rotor is pointing exactly at one of the plug wire contacts inside 
the cap.  If it's wrong, the spark will have to jump too great a distance 
inside the cap to the appropriate plug wire contact (which will be ahead 
of, or behind, the rotor as it passes by), and the spark at the plugs will 
be degraded.  Same symptoms occur if the shutter wheel is positioned 
wrong.  The blackening you described inside the cap may be an important 
clue.  Is it possible that you have a mismatched cap and rotor?

I can't explain the problem that initially occurred after your long drive, 
but at this point your plugs may be fouled and might require cleaning or 
replacement.  Perhaps something moved out of alignment, or consider that 
the problem is not ignition related.  Crane has a hotline to call for tech 
support, and after you check the stuff I mentioned, perhaps a call would do 
some good.    I'm very familiar with the Crane stuff, so let me know if 
there's anything else I might do to help.

Regards,

Dean

At 08:52 PM 8/12/2002, you wrote:

> Date: Mon, 12 Aug 2002 15:30:38 -0700
> From: "Stefano Iachella"<iachella@domain.elided>
> Subject: Suspecting problems with Crane 700
>
> Hey cats,
>
> Can anyone with experience with the Crane XR700
> system read this and comment please?
>
> I have a recent rebuild (under 350 miles so far)
> on my 74 GTV, and had my builder put the XR700
> kit on my Bosch distributor and a PS91 coil. I'm
> breaking it in, and it pulls great. I go on a
> 100 mile trip this weekend, and on the way back
> I get some hesistating. This is about 300 miles
> into the rebuild. It feels a bit like the old
> low fuel pressure sputter. Just a slight
> hesistation, but I made it back home.
>
> I had seen this with low tank and bad filters, so
> I go to top off the tank, and it is sputtering
> bad at this point. No change. I am thinking maybe
> the little wheel or the optical mechanism is
> loose or dirty, so I pull the distributor cap off.
> First off, the 4 contacts inside are black - this
> is a new cap and rotor. I scrape the contacts and
> rotor tip off. The optical mechanism seems tight.
> The wheel seems to rotate a mm or two each way,
> but otherwise it seems secure.
>
> I start up, and drive around. Still sputtering,
> like running on 2 or 3 cylinders now. I shut down
> and let sit for an hour. I start up and it runs
> great. I drive around for 1/2 hour with no ill
> effects; it pulls like crazy again.
>
> This morning it was a very hard start and when it
> finally turned over, it felt like only 1 cylinder.
> I couldn't drive it. I shut it off and tried a
> few more times and couldn't get it to catch.
>
> Any ideas? Does it sound like something with the
> XR700 setup?
>
> Thanks,
> Stefano
> Oakland, CA
>
> ------------------------------
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