Fuel Consump. Problem

[donburns at macconnect.com]

Wow! Lots of feedback! I'm sure I'll learn something from you guys. I'll try
to answer the questions and points raised.

Shannen, yes, I think its a F car engine, no aluminum, all cast iron. The guy
who did the swap calls it a LM1. I have never seen this term on a GM website
(have searched for it) but as I understand its the "smallest" of the 350s with
peak bhp somewhere around 275 or 285. Whatever it is, it moves this 2700 lb
car very well.

I have used two chips in the car, both marked mild, and the numbers and performance
seem to be about the same with either. ECM is the standard for this engine/year,
can't recall the number but it is referrenced on the diy-gm website. Part number
has two or three 7s in it.

Injectors are black, except for one which seems to have lost its color over
the past year and is kind of silver-gray now. I don't recall seeing numbers
on them but will take a look tonight. Knowing my luck the number is on the back
side so I'll use a mirror.

I have given the exhaust leak some thought. A few months back the pipe with
the O2 sensor came loose at the output of the ram's horn. Don't know why. I
put a new Chevy donut in and tightened it up, and its been OK since. I don't
hear any spitting there so my assumption is there is no leak. How much of a
leak will it take to upset the O2 sensor??

No headers on the engine, just RAM's horns. Exhausts are totally separate with
a CAT in each. No mufflers, just resonator tips. Sounds nice. I do have a leak
at the weld joint of the pipe and CAT on the side with the O2 sensor. But this
leak is 2 feet down stream from the O2 sensor. Can O2 be coming in here and
making it all the way back up to the sensor?? Am I staring at my problem and
not seeing it??? Welding this hole closed has been on my to-do list but have
not got around to it.

Bruce, you asked about a K/Pa reading. Are you talking about vacume? As mentioned
above this is the small 350. Does LM1 mean anything to you? Nope, I have no
equipment to read or burn eproms.

Bob, you cast another vote on the exhaust leak. Maybe I better climb underneath
and retighten those bolts at the RAM's head, and get the hole at the CAT welded.
The plugs are your basic rich running black. There's no question that the engine
is getting to much fuel. I don't see/hear/feel any evidence of misfiring.

I'm flying to Minneapolis tomorrow morning on business and back on Friday. I'll
try to read and post injector numbers tonight but will not have time to do more.
Thanks a bunch for all the ideas/suggestions everyone. 

Don
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