Thanks for reading my post.

I have a 2.3 stroker on E85 and I am trying to get it tuned with TScomptuned but it seems to be leaning out on the upper rpms. TSComp told me that it can not be tuned with this issue. We have addressed and changed almost every component in the fuel system and he is claiming the fuel pressure is too high; and says that it cannot be fixed via tune. I am not 100% sure if this is accurate or not; I would like to add more fuel if possible on the basemap.

Another Tuner (who I don't want to name) says the issue is related to the use of Speed density with the stock ECU and the fuel pressure is most likely fine with the car.

I wanted to see if someone can help me figure out if the fuel pressure needs to be fixed, or if the car can be tuned as it is. I am getting about 11s and then a high 12 around 6k rpms for the AFR reading. The knock count is at 2.

Here are the mods:
-FP black journal bearing turbo
-stainless steel turbo housing with 38 mm tial wastegate
-3" STM downpipe
-ams intercooler
-piping is mixed up a bit with hks blow off valve

Motor:
-gsc r2 cams 5041 valvespring / retainer kit for the r2 cam
-adjustable cam gears
-Manley 100mm crank
-I beam rods (forgot the brand)
-weisco hd 0.020 overbore pistons
- ported stock intake and exhaust manifold
-ARP head studs

Fuel system:
-stock oem fuel pressure regulator
-aem fuel rail
-Buschur double pumper
-Fuel pressure gauge on the rail
-FIC 1650 injectors
-I have the aeromotive fpr but tscomptuned advised to use stock oem to lower fuel pressure.

I can submit a data log and evo scan rom on the next post. Possibly someone can help me to put a bit more fuel at wot 5500+ rpms? Am I looking to run the afr to about 11.8, if I am not mistaken?

 

Too high of fuel pressure would cause a lean condition, not a rich condition. So what exactly is going on?

Running a dual 255 pump on the stock fpr isn't really ideal. Especially if you're also running the stock feed and return lines. 11.5-11.8 on E85 is safe. 12.0 is fine as well. 12.5 is about the limit, and not considered safe by many.

I wouldn't post Tom's ROM without getting an okay to do so first. But yes, post a log...

 

Thanks for the reply. The AFR is hitting a max of 12.9-13.1 at the higher rpms (6000+ RPMS)

 

Here is the data log file

 

You can add fuel, but that would be a band-aid fix if there is in fact a mechanical issue. If your fpr is getting overrun as the second pump kicks on then the increase in pressure may be limiting the injectors ability to open as effectively. I've seen this happen with precision 1200's before. If your your 1650's are the lowZ variety it could be the case for your situation. Another possibility is that your fuel pressure is dropping off.

Before you take any action, however, I'd encourage you to have an accurate understanding of the problem. I'd suggest monitoring your fuel pressure during a pull to see whether you are getting too much or too little pressure at the rail.

If the mechanical solution is to ensure that your fuel pressure is properly regulated by a fpr that isn't being overrun, then you should consider using the Aeromotive fpr. Another step to take is to drill out your siphon return tube. Ted B has a thread on why that is necessary and how to do it, however his symptoms were the opposite of yours IIRC.

Lastly, I'm not sure why your AFR's are in the 11's at all. Your target AFR should be between 12.0 - 12.2.

I'm curious to see the outcome of this. Good luck!

 

I am not sure if this variant of the 1650 is the "low Z." I chose this injector because it was advertised to work with E85 and C16 as well; the 2150cc FIC injectors were not compatible with C16 fuel. I didn't intend on running c16 but I figured just incase..... The injectors were recommended by multiple tuners.

Since my Fuel pressure gauge is on the fuel rail, its difficult to see what the pressure is throughout the rpm range.

However; we are getting about 50psi of fuel pressure at Idle. Do you think it would be helpful to rev the motor up a bit and monitor the gauge at the fuel rail while the car isn't moving?

 

It leans out from the get go. As soon as it starts coming into boost, you're at 10 flat, and it just progressively leans out from there. Something definitely isn't right in the fuel system, the requested injector pulse width doesn't even line up with your AFR's. Are you sure the second pump is coming on?

 

I was wondering the same thing actually. We just installed the double pumper over the weekend. Before that we were running the warlboro 450 and it did pretty much the same thing.

 

The second fuel pump is kicking in. I just recorded a video of the fuel pressure jumping up to 75 psi when the second pump kicks in; under boost. We taped the phone to the valve cover to watch the gauge on the fuel rail itself.


So the second pump is definitely kicking in. The fuel pressure with only one pump is around 50.

 

That should be fine then.

 

Would you try to add fuel to the tune at this point? Or try something else?

 

With a double pumper w 2x255's and stock regulator, my fuel pressure is at 38-40ish while idle. Are you on stock regulator or adjustable? You mentioned you have both..

 

I haven't seen the ROM, but something tells me Tom thinks something is wrong because he has to keep adding fuel and he's not seeing changes. How much boost are you making?

 

Right now we have the stock FPR on the car. It boosts up to 26 psi. The fuel pressure is in the high 30s almost to 40 at idle.

 

That sounds normal for fuel pressure then..