Hesitation only under hard boost

**RUTHLESS** · 08-12-2007, 01:40 PM

Hey guys! The car has been running great since I fixed the spark plug problem and found a few more HP. lol

Yesterday while running a street bike I went WOT and ran the old girl to her limits and found a problem. Beside the back end wanting to spin on small bumps!! lol I think the problem it has to do with the MAF being close to maxing out as we saw on the dyno. Here is the story.
I was just playing with the guy on the bike until he took off so I down shifter to third gear and went WOT. The car started to pull then just stopped! The boost was holding fine but the RPMs were not going up at all. It didn’t buck or make any odd noises so I backed off the throttle and pushed it down again and she started pulling hard. I thought it was an odd at first and didn’t think much of it. As the bike and I came to a bend we both slowed down. (Hey we were just playing and didn’t want to kill each other.) At the next straight away it was on again! I was in third gear this time and in my power range so I smashed the gas. The cobra was pulling hard until about 5k rpm then I hit that darn hesitation spot again and stopped pulling, the bike was pulling away, so I eased off the gas just a little and smashed it again and she came to life and put me in the trunk!
So what is going on here? From what I read it seems like fuel cut caused by the MAF maxing out. AM I on the right track? I don’t plan to run the car hard again until I get this fixed. For the people that don’t know...The fuel system is stock and so is the MAF. I am running a 2.93 upper on a ported blower with mid length headers.

**Viper_ed** · 08-12-2007, 01:47 PM

If you're at 472 rwhp with just the stock MAF and you don't have a MAFia, I would say that's your problem. From what I remember, the 460 rwhp mark is where 95% of the cars already have the MAF pegged at 5.0v.

**Blackcobraconv** · 08-12-2007, 01:53 PM

I know someone with a brand new Mafia for sale if you need one.

**RUTHLESS** · 08-12-2007, 02:28 PM

Viper_ed,
That was my thinking too. On question...If I get the MAFia would I need a retune? My guess is yes because my understanding is that the MAFia moves the MAF scaling down.

**u1arunit** · 08-12-2007, 04:06 PM

Originally Posted by RUTHLESS

Viper_ed,
That was my thinking too. On question...If I get the MAFia would I need a retune? My guess is yes because my understanding is that the MAFia moves the MAF scaling down.

Yep you would need a re-scaled MAF curve tune.