What now??

[mamato2]

I had custom gauges put in my 83 chevy c10 over the winter. My fuel gauge has never worked right, so i had a new sending unit put in it (still doesn't work, but that's another, non-urgent problem). After the replacement of the sending unit, my truck kept bogging down and dying. Turned out there was excess fuel line, which instead of being in the gas tank had gotten crimped in a "V" shape between the tank and the truck when the tank was replaced. We cut the excess fuel line off and put the tank back up. In the meantime, I also replaced the ignition module. Those are really the only two repairs she has needed this summer til now (wanted to let you know what had been done, in case i screwed something up, causing this new problem). The truck had started to run rough, in idle or during driving - kind of hesitating, lacking some power and backfiring. But only sporadically - sometimes it would do it and other times it was fine. I bought fuel system cleaner and dry gas in case anything had gotten into the tank when it was dropped. After i put that in it, it ran fine for 3 days, but has since started again and the truck is really sluggish now. I checked the fuel and air filters, which are fine, the fuel pump is new and i had a brand new edelbrock put in it over the winter. I checked for a vacuum leak, but that seems fine too. I don't know where to look next. It reeks of gas, but always has and my mileage sucks (averaging 6 or 7 miles a gallon). Also, as i was driving it to work last night, 3 times i heard a loud knock under the truck - i know it wasn't a backfire - it was extremely loud, seemed like it came from the drivers side. Almost sounds like a hammer strike against something solid - like the wood in the bed or a solid steel component. Scared the crap outta me. When i turned into the parking lot at work (there is a big speedbump there), the truck sounded like it made a cracking/grinding noise as she went over the bump. I am not sure what could be causing this either. Ughh.... Well, this is a long post - thank you for taking the time to read it. Any advice or thoughts on what to do next would be greatly appreciated!! Thank you.

[nbpro]

maybe a bad ignition module ? I have heard of these being bad when bought new. Years ago when I worked at a ford dealership, i saw it more than once. and a couple of times at the chevrolet dealership that i worked at.also this may cause it to bog and backfire. new edelbrock is this on a stock engine? what size engine and eddy ? sometimes they need a kit bought to be properly tuned. as far as the noise, its hard to say.

[mamato2]

Is there a way to tell if it is the ignition module that is bad before pulling it off and putting on a new one? I hate to waste money on another one, if it is not that. The engine that's in it is a rebuilt 350. Around 45,000 miles on the rebuild. Not sure what size the edelbrock is. It's a four-barrell. My mechanic gave me the part number to order it with at the parts store. One of the guys i work with said the banging could indicate water in the fuel, that has gotten into the cylinders. He said it makes a wicked loud noise when it's hit by the piston. I spent a good half hour underneath her today and didn't see anything loose that could be causing the noise. However, i did already use dry gas, which cleared it up for a few days, so if it is water in the fuel, wouldn't that problem be solved?

[nbpro]

look at Spark Control Causes

http://www.chevytalk.org/fusionbb/sh...hp?tid/176666/

ignition module

YouTube- GM Type I Ignition System...

as for water in the fuel i would pull da tank and clean it. still may be sediments in the bottom of the tank. hope this helps. good luck