another injector post

[minytrker]

Im having problem with 42s at idle. This is on a 98 transam with a 408, heads, cam, and direct port. I cant get it to quit fouling out plugs to even get it out the shop to tune it. Its running pig rich at idle even though the a/f is reading 14.7. Its dumping so much fuel, it blows black smoke and fouls the plugs after a few mins. I have rescaled the injector table (B4001) in efi. Im guessing I need to mess with the injector pulse width to get these to idle right (B3701). How much should you change this table by? Also what other tables should I mess with?

Thanks

[Biggsy]

A/F reading 14.7? Is that the WB02 reading or what the PCM is trying to call for?

If the WB02 is reading 14.7 then I would say you have a problem with the WB02.

[minytrker]

Its not the wb. I think its getting a false reading from the cam size. I ran into this with my vette and 50lb injectors, I could get the a/f to 14.7 and it would still blow black smoke at idle and foul out plugs. I finally just went back to 36lbs and it ran fine.

[Redline Motorsports]

42's huh.......wait till Andrew chimes in! LOL! These are his favorite injectors.

I still don't know why some have no problems with them and others fight with them. Sometimes I wonder if there are just bad sets out there. They are a cheap injector.....

Personally if the fueling demands are close enough, the 60 lb MOTRONS are great. Even idle quality is good.

When you said you scaled the injectors, did you change it from the "correct" values to see if it makes a globally large change?

[Doc]

Ok forgive me for asking but what kind of fuel pressure are you seeing at idle?

[minytrker]

42's huh.......wait till Andrew chimes in! LOL! These are his favorite injectors.

I still don't know why some have no problems with them and others fight with them. Sometimes I wonder if there are just bad sets out there. They are a cheap injector.....

Personally if the fueling demands are close enough, the 60 lb MOTRONS are great. Even idle quality is good.

When you said you scaled the injectors, did you change it from the "correct" values to see if it makes a globally large change?

I changed it from the correct values and tried some from a spredsheet, with the same results from both.

[minytrker]

Ok forgive me for asking but what kind of fuel pressure are you seeing at idle?

Thats the next thing Im checking when I mess with the car next. We pulled off the direct port and put on a known good stock fuel rail and stock injectors in just to see if we can get this thing to run longer than 5 mins without going through a set of plugs.