Josh B

I went out to the dyno last November and got these dismal results with my car - mods at that time were Vitesse MAF and chip boards, 65lb injectors, 3 bar FPR, 3" SFR exhaust, tial 38mm wastegate and lindsey intake. Boost was set to 15lbs. A/F ratio was off the chart.



I put 55lb injectors on the car after the dyno and my A/F ratio improved. I was getting low 11s under boost and WOT and normal partial throttle no boost around 14.7 - maybe a tic higher at idle.

That was with a hand held Innovate unit. I ended up selling that and picked up an Innovate LC-1. Got it installed this weekend. Now I have a 60-1 turbokinetics turbo on the car and a widefire headgasket and a worked head. My A/F ratio is still low 11s under boost and 14s under normal driving no boost.



I've since sold the 65lb injectors because I picked up a set of 72lbs. Vitesse had offered to re-flash my chips for the 65lb setting to ensure that wasn't the issue with the car running rich. Now that I am moving to the 72lb setup though he quoted me $400 to re-flash the chips for that. I have a SMT-6 that I can hook up and I am wondering if I would just hook that up - put the car on a dyno with the 72lb injectors and tune the car out for them using the piggeyback?

On Satuday when I was putting the car through emissions I was watching the fuel pressure guage when the car was on the machine. At 25 miles an hour it was showing a fuel pressure of 35lbs - I did not pull off the vaccum line on the FPR. At idle if I pull the vaccum line it shows 45lbs of fuel pressure.

cruise98

Josh:

The fuel pressure should be 3.0 bar at idle with the vacuum line disconnected and plugged. The fuel pressure will increase with boost, and decrease with vacuum. When you reconnect the vacuum line, the pressure will drop slightly.

What are the compression and leak down numbers on your engine? Are you getting full boost and at what rpm?

95ONE

your observed fuel pressures are what they should be for those conditions.

Josh B

Compression numbers are 130 to 135 across all four. Haven't done a leak-down test. With the stock turbo (k26/6) I was getting 15lbs of boost at around 3500 RPMs (that is what was on the car at the dyno) but with both of the aftermarket turbos I am not seeing a bar of boost until after 4000. I am hoping that is a tuning issue and not a turbo issue. I have a #8 hotside on the current turbo. I think I have some crossover leaks - I am trying to get the car on a smoke machine to track those down...

fast951

Josh, there is something causing the car to run overly rich. Tuning with the PiggyBack just covers the real issue. You are supplying your own injectors, I stand behind my products, this is why I offered to reflash the original setup "for free" to see if it made a difference. I also offered to run the Motronic Monitor on your car for "free". Upgrading the injectors to a different brand & flow requires a software upgrade, we do charge for "upgrades".
Many things can cause a rich AFR, it's best to find the real cause.

Josh B

Hey John - Thanks so much for your generous offers of help. I guess I should have taken you up on the re-flashing offer before I sold the 65lb injectors.

The problem is that I use this car as a daily driver and have to be at work from 8 to 5 every day of the week. I wouldn't want to assume on your evenings or weekends and I can't take a day off work right now to meet you during the day.

Were the observations on the dyno enough to rule out a pinched fuel line at least?

My intake pressure is showing at about 12 -14 on start up and 16 when the car is warmed up.

fast951

Josh, high fuel pressure caused by a pinched line will cause the AFR to go up. However, this may or may not be the cause. Having said that, other variables could cause the rich condition. The Motronic Monitor would have given us a real live picture of all of the variables (sensors etc..). However if physical conditions (pinched line) is the cause, it cannot be detected by reading the data from the DME.

Antonio951

Im in a similar boat as you Josh....very VERY frustrating!
I have the vitesse setup as well, spoke to John and he told me to do a pressure test. I had a leak around the throttle body and its getting fixed this week.
That was nice of John to offer you a FREE reflash.....

Keithr726

I'm having the same problem but luckily my AFRs do not go below 10 but still thats too much.

Also, thats kinda late for a 26/6 to reach 15psi. I get 15 just before 3,000rpm.

fast951

What are your mods? Are you using the same Vitesse setup as Josh?

Josh B

Can't I eliminate the pinched fuel line based on my fuel pressure observations when the car was on the emissions dyno?

fast951

Vacuum leaks will cause the car to run lean at idle & PT and rich under boost.
Every now and then, when the cause of a issue is not obvious, a reflash is verified to be certain. At times, we spend countless hours supporting a customer, to find out that the real cause of the problem has nothing to do with our products, so we eat the loss in time. A flash verification is the easiest part.

Support policy is about to change, as it has been abused by some (none here!).

fast951

I would not. I would verify fuel pressure under boost/load! Meanwhile, make a list of items to go through and double check. Installing the PiggyBack helps as you can log many variables and replay later.

Antonio951

I hope i havent abused the support.
I have a few more tests to do before i make a final conclusion.