No fuel at boost

[CleanPalms]

I recently purchased my first DSM with the issue thats present in the subject line. All my mods as accurate as I can name them are in my profile. Using an AFC NEO to tune fuel/air I have an issue building boost. Any boost. I have several questions regarding the subject. I most definitely have spent 3 days searching this issue out and if there is already a post on this, I apologize I missed it. Let me begin by stating that I thank and appreciate every and all bits of information given to me by the members of this site. Onto the issue:

1. Using NEO to tune, is seems + numbers need to be in large amounts in order to even begin richening out the fuel:air. The wideband I'm using takes 2-3 seconds at a constant throttle position/speed in order to accurately display the AFRs. And it ALWAYS shows super lean (---) or (17.0-18.0) initially, regardless of NEO setting, is this normal?
   
2. Idling with no neo correction makes the car stall out so I know the neo is working somewhat, but the numbers required to idle or operate the car correctly are outrageous in my opinion. Ex. +30 at Ne1 (1000rpm) and more at each Ne point, is this normal?
   
3. The car runs normally at low throttle and while slowly increasing RPM, WOT makes the car spit and sputter, like it can't adjust fast enough. And even low throttle but attempting to build boost (any at all) makes the car spit and sputter like crazy! In it's simplest form, it is impossible for my car to build boost.

Some other things that are possibly worth mentioning:

• 1. Car was originally an automatic, and I've been told the ECU is still the automatic one.
• 2. MBC has been set both ways (all the way open, all the way closed) no change.
• 3. I've read many neo usage posts and articles so I'm pretty sure I'm utilizing it correctly. + Numbers = more fuel = richening out. - Numbers = less fuel = leaning out. Unless I'm confusing the two. But I've tried it both ways and have gotten no change anyway so that doesnt matter.

I just purchased EvoScan so I can now start logging, but don't know what it is that I should be looking for. So if someone wants me to provide a log or something, I could probably do that if you tell me which options to select. Thanks again!

 

[H4G64T]

Then the NEO would be capable of adjusting for those. The way I understand it, from what the APEX'i guy told me, is that the NEO is unable to properly read the information from the MAF because it lacks KARMAN support and as such it is not able to relay it to the computer properly, which is causing the problem.

 

[CleanPalms]

Then the NEO would be capable of adjusting for those. The way I understand it, from what the APEX'i guy told me, is that the NEO is unable to properly read the information from the MAF because it lacks KARMAN support and as such it is not able to relay it to the computer properly, which is causing the problem.

That makes sense, but I've set the neo for "No Correct" which in a sense should be transparent on the MAF circuitry and allow the ECU to correct for itself. Even shorted the wires without the NEO plugged in and it caused the same issue. The ECU is unable to keep the car alive with the NEO. haha. Is this cause by the upgraded fuel system?

 

[H4G64T]

Yes, the larger injectors are going to cause the problem in that instance because the ECU has no way of knowing that they aren't 450CC injectors. That sounds about right, we put 550s in my buddies stock GST and the car idled real rough and wanted to die and it backfired a lot on WOT and struggled under boost.

 

[CleanPalms]

Yes, the larger injectors are going to cause the problem in that instance because the ECU has no way of knowing that they aren't 450CC injectors. That sounds about right, we put 550s in my buddies stock GST and the car idled real rough and wanted to die and it backfired a lot on WOT and struggled under boost.

Okay well I'll definitely give a call today and try to get my stuff sent out. In the mean time I'll test the fuel pump idea too. My friend has a stock evo9 pump that was used to run the stock 550cc injectors so i don't see a reason why it couldnt support the 560s. Am I completely wrong on this or should I continue with the test?

 

[H4G64T]

The Evo fuel pump will be more than enough for the 560s.

 

[CleanPalms]

The Evo fuel pump will be more than enough for the 560s.

Took a look at the firmware version and it's actually 1.104. 1 build version newer then the 1.103 with the karman sensor issues. Mine still doesn't have a karman sticker on the back so when they open in 2 hours I will be giving them a call to see if my version is still a little too old.

 

[Hugolm10]

You're right it sounds like we are having a similar, if not the exact same problem. Except I can't even creep into boost without it backfiring like crazy. I was told by the previous owner that the Walboro 255 was a brand new pump and just makes me feel terrible that I would even have to replace it haha. But if thats it, then that's it. I just dislike spending money on things I can't really PROVE is causing the issue.

Another thing worth noting that my friend mentioned is that the stock boost gauge on the cluster is reading 100% boost before I reach fuel cut. Which just so happens to be the reading as just entering boost on my aftermarket boost gauge. Possibly related?

You mentioned that if I perform the pressure test at idle and what not it would give accurate readings but during WOT the pump just cant handle adjusting the fuel pressure? Am I right? How could I test for this besides keeping my car in the state of "hitting the wall" (WOT) so I can read the pressure? What should my pressure be under WOT?

Also, it seems like this matters according to some posters. If I have stock injectors (which i dont), I am running the stock FPR. Per the manual, without removing the vacuum line and plugging it with my finger, I should be reading 33psi and when removing the vacuum and plugging it, between 42 and 45psi. Is this also correct?

Yea I know that's the only bad side to it... I mean I tested the fuel pressure n I got perfect numbers like if nothing was bad so I ruled out fuel pump injectors fuel filter or even a crimped fuel hose or line. However the fuel pressure under WOT should be bigger and I guess my fuel pump wasn't releasing the pressure it was supposed to under WOT and idk how to check under WOT pressure. The fuel pump I had was a "255 walbro same one u had some what new what made it go bad I'm thinking was that the car wasn't moved for a while. I later researched and saw that 255 walbros fail a lot thats why this time I went with a forced performance 255 and Evo fuel pumps are bolt on fuel pumps 2 I believe the part number is gss342...

 

[Hugolm10]

Oh and I forgot to mention I would also get some backfire when the fuel would cut off like you said you were having. At first I thought fuel cut but then when I got the keydiver chip it comes with fuel cut delete and it still did the same so backfire is a symptom of it

 

[CleanPalms]

The Evo fuel pump will be more than enough for the 560s.

Just to let you and everyone else know my progress on the issue. I contacted APEXi technical support and was told that my serial number was included in the batch of those without karman support. However, becaused my firmware version is 1.104 this means the previous owner of the NEO had already had the firmware flashed. 1.104 and newer supports the karman sensor.

Waiting for my buddy to get home so we can swap out my wally255 with his evo9 stock fuel pump.

Alright, so I think this is a pretty major update but those seasoned veterans will have to let me know for sure.

I Pulled the pump today and took a look at the o-ring and the spacer below the o-ring. Pictures are posted below. Let me know if this could be the culprit! The space for the o-ring looks like a blue rubber piece and half of it was completely torn to shreds. On the torn out half, the o-ring was blown completely out of the housing leaving only half the o-ring inside.

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EDIT: Where could I pick up another spacer? O-Ring is still in good shape.

 

[CleanPalms]

Okay so today in the midst of all the moving I was doing I took some time out to play with the fuel pump. I used a small vacuum hose as the spacer, lubed it up, slipped the o-ring over it and the cap on top and then into the housing it went.

Ta Da! Problem resolved.

Problem: Fuel pump with blown o-ring and missing spacer cause pump to be unable to supply proper fuel pressure.

Resolution: Replaced spacer with vacuum tube about the same diameter as the o-ring and restored the pump.

Thanks again to everyone who helped me out on this issue! I greatly appreciated it! A boosting we will go!