My car just started backfiring after I get on it, and it definatly has a loss of power. The motor has about 20k miles on it. it definatly runs rich and normally pops when you let off the gas at hi rpm in like 2nd, but now it will backfire like a 12 gauge coasting in fourth and it will let out a big puff of smoke.

changes out the plugs and O2 sensor didn't help

only change on the car since I put the motor in was about 1500 miles ago I put in a crane fireball HI 6 ignition and LX92 coil.

Any ideas?


Any help would be much appreciated.

Thanks,
Ryan

 

You need a custom prom extremely badly. Your tune has got to be WAY off with a 350 with vortec heads and a cam running on the stock 305 TBI tune. Read the "new to TBI" thread at the top of this forum and read about Chip tuning.

 

very true I know my car has a lot more potential if i would do some prom tuneing but it ran like a bat out of hell for 20k miles(just rich) and now it has some problems

any ideas

thanks again
ryan

 

If it ran somewhat normal before I would check your base timing. I would bump the timing to at least 8* and crank the fuel pressure. That will be a nice band aid until your chip burning stuff arrives. hint hint

 

Yeah, I'd also say that since it happens when you get on the throttle that you might want to install a fuel pressure gauge and try to monitor the fuel pressure under load. Your fuel pump may be going.

P.S. How do you like that Gforce T5 rebuild?

 

Something else I am wondering is if I fouled out my cat, it does run a little better when it warms up, but not like it used to.

isn't backfiring caused by it running rich? so would a bad fuel pump cause that?

the G-force rebuild was fairly easy just lots of small parts (but then again I fix nuclear reactors for a living). Just get the video from hanlon motor sports, it is awsome, and the people there are awsome. They awnsered all my questions were familiar with the G-Force kit. When I had questions and the techs were busy, they called me back 10 min later. There service sells.

Thanks for the input guys

ryan

(ps anyone in upstate NY that would help me when I start burning chips for beer?)

 

chip burning,.,.,.,., Probably something you DONT want to do when drunk... Just hink of the possibilities..

 

well I finally broke down and ordered chip burning stuff. anyone know what I need to order to replace my fuel lines from the hard lines on the frame rail up to the TB and install a press gauge. I have seen a list before but I couldn't find it.

thanks again

Ryan

 

check out aeroquip push on fittings and elastomer(?) hose. cuts with a utilty knife and push on fit to adapter after heating in water. i used it on my set up and will use again for my 7.4L TB install.. they offer an adapter to splice onto your hard lines back to gas tank. now earls came out with something simlilar(braded nylon) but suspect the fittings are compression style. aeroq are probably patented.

 

Here's a list of parts for a braided fuel line setup. HERE

 

thanks just ordered that stuff and a fuel press gauge

where does everyone recomend getting a walbro 255 fuel pump?

Thanks again
ryan

 

I like this place. Cheap pumps, quick delivery. http://www.autoperformanceengineering.com/

 

ordered the fuel pump HP 255 lph one thanks

ryan

 

ok I installed a fuel press gauge and 65# injectors today.
and noticed a possible exhaust header leak. could the leak sound like knock and cause a rich condition causing my problem?

thanks

 

oh and what should my fuel press be? I can't get mine over like 8 psig,
and the bigger line is the supply line right?

thanks again