I installed a Jacobs RV Ultrateam kit into my '91 Ford F-150 yesterday, and notice that the truck has less low-end than it did before the install.

Has anyone else noticed this with the Jacobs kits? Mid range SEEMS better, but I can no longer accelerate, for instance, from 45-50 without the truck downshifting. Truck also loses speed and downshifts on a hill that I can otherwise take (lose speed, no downshift) with the kit disconnected (pulled fuse and reconnect stock coil-distributor wire.)

What's going on?!?!? Or is some loss of low-end normal?

I regapped the plugs to 0.064" as recommended by Jacobs (standard gap is 0.044").

Thanks,
-Mike

 

http://www.se-r.net/engine/ignition.html

there are some criticisms on that page, plus I was searching for a report on a mustang (i think) project car that they found some losses of torque (i think that's what it was - at some RPM level) on. I couldn't find it (but I did view the page within the last two months, so I bet it's still out there). But I did find a number of criticisms over Jacobs ignition claims and performance. It seems to be an over-rated CDI box... equal to other mid-level CDI boxes, but lacking the extra kick out of MSD's patented multiple sparks. But then a lot of people seem satisfied with Jacobs, too.

(here's a less-than informitive criticism of the ignition:
http://www.goingfaster.com/spo/gallery.html )

After all that searching and reading I just did, I'm a little more relieved I bought the MSD a month ago. Sorry if that sounds biased, but this was my first CDI purchase, so I'm a bit glad I came out ahead on the deal. I wanted the multiple sparks under 3500 RPM anyway because the I-6 isn't a high revving engine like the V-8's.

One post indicated a guy did bitch at Jacobs, with dyno sheets to prove that there was no improvement, but to no avail.

Have you checked your timing before and after installation?

 

Just a quick note. I put a Jacobs system in my '94 F-350 crew/dually (460/auto)and really didn't notice much difference. However, at about 1500 miles out of warranty, the Jacobs coil unit went bad. I replaced the spent unit with my stock unit (which I held on to) and disconnected the Jacobs computer and the truck ran fine till I sold the truck. Jacobs was no help, indicating that since the coil was out of warranty, there was nothing they could do... except sell me another one.

 

I tried Jacobs a few years ago. It was their top of the line "Ultra Team" and the system would not work as designed with the 302 V8 in my 89 F150. It caused a low to mid rpm misfire under load. Jacobs was no help in that all they could do was take the system back for a 10% restocking fee. What a RIPOFF! Buy an MSD system.
Mark