It's not that. You have more than enough fueling at 11-psi of boost pressure, what's happening is the O2 sensor is not registering the raw fuel that is shooting out of the exhaust due to the excessive overlap, which is why your air/fuel ratio is good, but Duty Cycle is high. You are only using 50% of that Duty Cycle despite the datalog showing 102% Duty Cycle. It's your camshaft, your injectors and pump are fine...

 

Log your fuel pressure so you know what it really is wide open. When I finally did it was an eye opener. Had a bad out of the box aeromotive afpr on my miniram. I couldn't figure it out until I saw it wasn't rising 1:1 with boost. I'm thinking if you're at that injector duty cycle but only using half, you'd be smoking like a diesel in your rear view.

 

Just got the filter sock in the mail yesterday for the walbro 340 pump and will put it on tonight to see if this pump and the stock wiring fixes my issue.

The duty cycle at WOT should be fixed with the cam swap, but the car cutting off after 15 minutes of driving is still a fuel pump issue. This did not happen until I changed to the racetronix wiring and added the 2nd pump. Since the 2nd pump is on it's own wiring and hobbs switch, I don't think it has anything to do with the stalling issue.

 

I had similar issue few years ago.Car runs fine ~1/2 hour, and then stalled.I put fuel pressure gauge to fuel rail and run it till stalled. Fuel pressure starts to drop and when it was low enough engine stops.Pump was bad(walbro F20000169) ,and it has very low mileage(~2000km/1 year)

 

A friends car did it... I drove it down the street and it spit and sputtered on the way back. When I pulled into my driveway it choked down slowly to a halt. When I got out of the car, I heard bubbling in the tank. I cracked the cap a bit, and that thing whistled like a tea kettle. Was a bad pump.

 

Chased my tail for months thinking it was a fuel issue and it seems to be the crank sensor. put a new one in and drove the car on the same loop that i drove when getting the bucking and sputtering and no issues. Seems i can only get 1 year of use out of crank sensors. I will buy a spare and keep it in the car with a jack stand and my mini track jack and be ready for the next time it happens.

Added another dynomax ultra flow muffler hoping to quiet the car down some more, but I am not sure if it helped any.

Gonna fix a header leak and then swap cams.

 

Back from the dead.

Sold the t-trim to anethes and picked up a used ysi-trim.
Changed cams from the 230-230 .600-.600 107lsa to 230-244 .580-.580 114lsa.
Car is running hot now that it is 90+ degrees out and i ordered the summit radiator to bring the temps down. I hate to see the coolant temp go above 200 on this car.

Trying to get a dyno appt to tune the car and see what it puts down.

 

Jesus, back from the dead again. This car is a curse and a money pit. After going through trans after trans I am running a 4L80E trans and it is still giving me fits.

Rebuilt the motor, put in the 4L80E which i have pulled 3 times already for a temp issue, changed cam from the 230 .600 107lsa cam to a 230-244 .585 .585 114lsa cam, dropped compression from 10.5:1 to 9:1 with JE pistons.

Just went to the dyno and put down 660 rwhp at 15 lbs at 6400 with 26 degrees on C16. Problem is, I am still not happy with that number.

Was bitching at the dyno place about how this high dollar blower isn't making the power every body else is making with it and the dyno guys suggest to put a boost sensor in the outlet of the blower to see how much boost it is making at the blower. They said they have a customer who is running high 7's with this same blower and it should be making more power. Made another pull and it is making 23lbs at the outlet of the blower vs 15 lbs at the motor. This junk ebay intercooler is eating up 8 lbs of boost. No i know where my boost is going. I have wasted money on different pullies, belts, serpentine tensioners trying to get boost up and it was the intercooler the whole time. They are going to give me a quote on a garrett core air to air, as they build their own intercoolers at the shop. Maybe i will make some decent power at sometime in my lifetime but not right now.

All i am trying to do is hit mid 9's in the quarter with this pile.

 

Looking at the data logs, i am hitting 85% injector duty cycle at 6450 with the 80lb injectors, so i might need to step up injector to some 95's. Running 45 psi at the regulator.

 

what bracket/belt/pulley setup are you running on the ysi?

 

SBC carbed bracket with my own joe dirt style bracket with a serpentine tensioner on it like the procharger tensioner. 10 rib 7.8 crank with 2.75 blower pulley that has been sandblasted for more traction.

 

If you have the fuel pump for it, go to 58 psi base but i wouldnt be scared to go over 95% dc lol

 

Holy christ.. I wonder if that's why I'm not seeing a lot of boost with the T-trim, and why it was popping open the greddy BOV.

What was the temperature difference though before and after the IC? My ebay chinese IC is taking a 200 degree charge and cooling it to like 70-80 degrees. I'd have to do a density calculator, but surely that results in some pressure drop.

I had some epic fueling issues too. Was getting pressure drop with the 400lph walbro, probably due to wiring. Re-wired with 10awg and installed a 525lph walbro, then I found the miniram/lt1 regulator couldn't flow enough back to the tank.

So I came up with this:






-- Joe

 

I didn't measure temp before and after the intercooler, only pressure. On that last dyno run, the temp at the start of the run was 86 degrees and went up to 100 degrees at the end of the run. Even the shop looked at the IAT numbers and said the intercooler is cooling well, but not flowing well. Apparently , there are different ebay intercoolers they all don't flow the same. You find some people saying they only got a 2 psi drop and are running in the 8's with an ebay intercooler, while some like me have an 8 psi drop.

When i made my miniram fuel rails dual feed, i went to an aeromotive external fpr which rises with boost at a 1:1 ratio.That is how mine is routed and what TPIS suggested: feed both rails from the back of the motor with a -8 or -6 line and have both -6 lines come out the front of the rails and go into the fpr.