Well, after about a month of messing with my Howell TBI on my '89 and trying to find out why it just would not perform as I had expected, I discovered today while doing some other work that the whole problem was with a vacuum leak between the intake manifold and the adapter base plate. Since I followed the directions very carefully during the install I thought there must be something wrong with the "tuning" of the entire system. Howell has been helpful with on the phone troubleshooting and sent me a new ECM when I described what problems I was having. After finding what the problem was, I cannot believe anyone else who installed this system did not have the same problems I did. What I found was, on both sides of the adapter plate (outer radius), when installed with the provided gaskets to the stock 2 bbl intake manifold, there was a gap between the manifold and base plate. This gap was partially covered with the Howell provided gasket but not completely. I have to think that maybe the adapter plate was not machined properly (not likey) or it was the wrong plate for a Jeep, or I did install something improperly (possible.) I removed the TBI, removed the adapter plate, and made a new gasket to go between the adapter plate and the manifold. In addition I used a bit of silicone to stick the gasket to the adapter plate and a bit on the intake manifold to basically "glue" things in place. I think I'm going to call Howell again and ask them about this "gap" and see if I did something wrong on the install or if perhaps they sent the wrong 2 bbl adapter. Once I reworked everything all my troubles went away. The trouble I was having was serious sluggishness when accelerating, idle speed was too high 1000 rpm, and just generally crappyness (technical term.) Now, it hauls azz, starts easier, idles about 600 RPM. I'm happy!!! I found this fit problem when installing my new HEI and noticing white smoke coming from between the intake manifold and TBI adapter plate when I shut the Jeep off. Used a bit of carb cleaner to verify leak while running and went from there to repair this. Now all I have to do is put on a new muffler as the TBI did some serious loading up and when I started it on Friday, it backfired to the point that it literally blew my muffler seam apart and now sounds like a tank. Maybe it'll improve my MPG with less back pressure
. Anyway, I'm happy and ready to go do some Jeepin'
. Now all I have to do is speak with Howell and get some answers. And how was your day?