jscherb
CJ-8 Member
- City
- Elmira
- State
- NY
What a difference! Smooth idling, easy cold starts, good cold running. And a box of about a million pieces of old vacuum hose, Carter carb, and other 80's emissions crap to take to the landfill.
Install took about 9 hours over 3 days, no real complications, although there are a couple of places where the Howell manual could be more clear.
I did a couple of things to make the job easier.
1. Did the "Nutter bypass" on the ignition and stock ECM a few weeks ago. The Howell conversion requires the same wiring change as the "Nutter", so doing this ahead of time removed one variable from the EFI install. Definitely worth doing in this sequence, because removing the stock wiring harness is a lot easier to do once you've done this change and know for sure what stays and what doesn't.
2. When I put in my new dash a few months ago, I ran 12v directly from the battery side of the solenoid to a relay under the dash. This relay is switched on by the "IGN/LPS" circuit, so it is powered during cranking and running. According to Howell, the most common problem they see is low voltage from somewhere in the stock harness, so this ensured I wouldn't have that problem.
3. Also when I did the dash, I modified a stock dash light with a "Check Engine" transparency I made along with a red light. Looks very cool to have a "stock" check engine light. See attached photo, sorry for the quality of the photo.
4. I downloaded Howell's install doc, and edited it together with info and photos from the SierraJeep.com Howell writeup (http://www.sierrajeep.com/howell.htm) and info from Dale Beckett's great "Adventures Under the Hood" writeup on stock emissions equipment (http://home.sprynet.com/~dale02/home.htm). This gave me a step-by-step instruction manual with exact photos for every step. Very helpful.
That's about it, everything else went pretty much by the book. Oh, one more thing, go to AutoZone and buy assortments of vacuum tees, reducers and caps. Each assortment cost me less than 3 bucks and I needed a few parts from each as I was plumbing the new vacuum lines.
If anyone is contemplating a Howell conversion and wants more info, just email me.
jeff
Install took about 9 hours over 3 days, no real complications, although there are a couple of places where the Howell manual could be more clear.
I did a couple of things to make the job easier.
1. Did the "Nutter bypass" on the ignition and stock ECM a few weeks ago. The Howell conversion requires the same wiring change as the "Nutter", so doing this ahead of time removed one variable from the EFI install. Definitely worth doing in this sequence, because removing the stock wiring harness is a lot easier to do once you've done this change and know for sure what stays and what doesn't.
2. When I put in my new dash a few months ago, I ran 12v directly from the battery side of the solenoid to a relay under the dash. This relay is switched on by the "IGN/LPS" circuit, so it is powered during cranking and running. According to Howell, the most common problem they see is low voltage from somewhere in the stock harness, so this ensured I wouldn't have that problem.
3. Also when I did the dash, I modified a stock dash light with a "Check Engine" transparency I made along with a red light. Looks very cool to have a "stock" check engine light. See attached photo, sorry for the quality of the photo.
4. I downloaded Howell's install doc, and edited it together with info and photos from the SierraJeep.com Howell writeup (http://www.sierrajeep.com/howell.htm) and info from Dale Beckett's great "Adventures Under the Hood" writeup on stock emissions equipment (http://home.sprynet.com/~dale02/home.htm). This gave me a step-by-step instruction manual with exact photos for every step. Very helpful.
That's about it, everything else went pretty much by the book. Oh, one more thing, go to AutoZone and buy assortments of vacuum tees, reducers and caps. Each assortment cost me less than 3 bucks and I needed a few parts from each as I was plumbing the new vacuum lines.
If anyone is contemplating a Howell conversion and wants more info, just email me.
jeff
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