Who out there has the Howell throttle body setup on their 4.2 and what are your opinions of it? Just curious what other think of it and the pluses and minuses you've seen with it.
Checking fuel pressure is not a bad idea, but I'd be more inclined to think it has a bad vacuum leak from your description. Lean exhaust is a condition where there is more air than fuel in the mixture. Check for a clogged fuel filter as well.I’ve been having a bit of a problem with mine. The PO installed it and it seems that he did a solid job. Also, luckily the service manual from Howell is really thorough and the flow charts are good.
It fires right up and runs for 2-3 seconds before dying. When it got up to normal operating temp by holding at about 1500 RMP it would stay running, but pretty rough.
It wasn’t storing any codes so today I did the tests in Field Service Mode and got it narrowed down to a lean exhaust and to use the code 44 chart. Code 44 is Oxygen Sensor Circuit (Lean Exhaust Indicated). So it was either bad fuel pressure or a bad O2 sensor. I threw a new O2 sensor today because it was only $15 and easy to do. It definitely helped some, but still idles a bit rough.
So, tomorrow I’m going to check the fuel pressure to see how that looks. Am I right in my thinking that a lean exhaust would point to low fuel pressure? I’ve never checked fuel pressure on any engine before so I’ll have to figure that out. If you’ve been down a similar road with yours or have advice on checking the fuel pressure I’d sure appreciate any help.