WOT sounds like machine gun, no power.

[williillii]

Having this problem with my 2g lately...started last week as a slight "breaking up" feeling in the upper rpms. Its progressed to the point where if I even go over 3-4psi it just falls on its face and goes BRAPBRAPBRAP really fast.

I notice if I just roll on the throttle real slow, sometimes it will make it up to 5-6k...afraid to take it any higher right now. Part throttle driving feels just like it always did..

Also this may be unrelated (as its done this for the past 6 months) but the car runs lean as well. ~12:1. My plugs are coming out white.

What I've done so far:

turned boost to stock
swapped plugs (bpr7es to bpr6es)
swapped wires
swapped coil pack
swapped power transistor
new FPR (I dunno, figured since it was lean maybe but no difference)

Any idea what this could be? It feels almost like I blew an IC pipe when i get over 4psi...but then I let off and go part throttle and it feels fine. I dont have access to an air compressor for a BLT at this time, but I have had many a boost leak and never felt anything like this. Will BLT as soon as I can borrow a compressor...but like I said it would have to be a whole pipe that blew off to feel like it does....

Any insight is appreciated.

Relevant mods:

14b
Front mount
evo ix fuel pump w/rewire @ 13.5v
550cc
intake/exhaust
wastegate dump

 

[And_44]

Fuel Filter?

 

[90moneypit]

Exhaust manifold leak?

 

[TurboATM]

A buddy of mine had a simular issue on his Exige S, and it ended up being one of the injectors... 2 of them were a little messed up, and not feeding enough gas when needed.

On my DSM i had an issue the same, and it was a boost leak. All of my boost leaks have anded up being somewhere that felt/looked 100% sealed on pipe connections when i checked them, yet open when under boost. (if that makes any sense...)

 

[williillii]

Hm...well Ill try a new fuel filter tomorrow.

No exhaust leaks. Replaced all the gaskets last week. Also just put the injectors in like 2 weeks ago. Thinkin theyre fine...if it comes down to it Ill pull the fuel rail for the FOURTH time this week . Thanks guys keep em comin..

 

[TurboTerror99]

You said you put the injectors in there a few weeks ago... what size are they and did it start acting up immediately after that?

 

[delta448]

What are you tuning for the injectors with?

If it happens only under boost it's most likely either bad MAS, insufficient spark, the fuel pump, a leaking FPR or the fuel filter.
From that list, you've eliminated the FPR and pretty much all of spark. Are the plugs gapped between 0.024" and 0.030"?

Fuel filter should be changed anyway if it's not been done.

Does the MAS still have all honeycombs, and is it the stock unit?

How old are the injectors? Been cleaned recently?

 

[Chrispy0530]

Are the plugs gapped between 0.024" and 0.030"?

This.

I'm almost willing to bet this is the problem. I had the very same exact symptoms you described, gapped my plugs at .28, and cured the problem. Same exact problem on my friends GS-T with the solution.

 

[williillii]

What are you tuning for the injectors with?

safc2

If it happens only under boost it's most likely either bad MAS, insufficient spark, the fuel pump, a leaking FPR or the fuel filter.
From that list, you've eliminated the FPR and pretty much all of spark. Are the plugs gapped between 0.024" and 0.030"?

fuel pump is oem evo ix with like 20k miles on it. I will pull it to check but I think it is fine. Is it ok to run water through it so see if it is flowing what it should?

Plugs gapped to .028. Even squished em to .025, nothing.

Fuel filter should be changed anyway if it's not been done.

Will change this first thing tomorrow.

Does the MAS still have all honeycombs, and is it the stock unit?

Honeycombs intact, stock no maft BS. Maf HZ is inline with what it should be so I think its ok.

How old are the injectors? Been cleaned recently?

good question. any idea what it costs to have them cleaned/tested? might put the 450cc back in to see what they feel like.

You said you put the injectors in there a few weeks ago... what size are they and did it start acting up immediately after that?

550cc, no it ran fine. It actually started a like a day after I put the wastegate dump tube on there. Could the dump tube be triggering the knock sensor or something stupid like that?

 

[delta448]

safc2

What are your settings?

fuel pump is oem evo ix with like 20k miles on it. I will pull it to check but I think it is fine. Is it ok to run water through it so see if it is flowing what it should?

Don't run water through the pump. Do use a pressure gauge to verify 43.5psi of fuel pressure at the rail with the vac line disconnected from the FPR.

good question. any idea what it costs to have them cleaned/tested? might put the 450cc back in to see what they feel like.

Cleaning and flow testing is usually ~$80-100. Remember to zero out the SAFC if you do put the 450s back in.

550cc, no it ran fine. It actually started a like a day after I put the wastegate dump tube on there. Could the dump tube be triggering the knock sensor or something stupid like that?

Yes. Got a log?
Any timing dips right around the time you hit full boost?

 

[williillii]

SAFC 2 settings are -18% low throttle and I have it at -5% across the board hi throttle because the car runs so lean. This gets it around 12:1AFR...any richer and it misses like crazy (well when it wasnt doing this bullshit its doing now) The high throttle settings really dont seem to do much of anything though. Throttle points are 25% and 80%, tps pointed up, airflow set to karman.

And I dont really have any way of logging. I have evoscan/openport cable but my car will barely connect to it. It will log for like 3 seconds then disconnect for 10 and retry a bunch. So its pretty much impossible to use.

Goin to the store to get some plugs wires and fuel pump now...

 

[delta448]

You NEED logging ability in order to tune your car with an SAFC. Without data on fuel trims and timing advance you're like a blind man carrying a sniper's rifle, ...but hey, at least you have a wideband.

After you get logging working, you might want to consider starting by adding quite a bit more fuel back in under the low setting, and lowering the high TH-point percentage a little. If you haven't read them yet, check out these two great SAFC articles in the tuning section: #1 and #2.

Since you're using injectors that probably don't flow as well as they used to, starting off with -18% is pretty bold.

Bottom line: you need a functioning logger immediately.

 

[williillii]

Changed the wires and fuel pump and its better now. I guess my spare wires were bad too .

Next step now is to get the logger working. Thanks for the info defiant. Turns out I actually did not know how the MAF meters air. The safc stuff I've dealt with before but that was neat

 

[92dsmgst]

Recirculated bov? min does this at around 5500rpms on the stock 1g bov unrecirculated. it sticks open or something, but its fine when recirculated.