weird stall at wot
 

i'm going to apologize in advance. this may be the wrong place for this question, but since i was uncertain, i just put it in general.

got an ap (v2) and tuned on the corksport stage 0 map until i got internals (also corksport). installed internals, everything went fine, no issues. tuned to stage 1.

whenever i go wot (in 3rd or 4th it's most noticeable) the car acts like it's not getting enough gas. it almost stutters and stalls. it's as if it's only firing on every other pass. scared the shit out of me at any rate.

detuned to stage 0, not nearly as noticeable, but still happens a little bit. i'm going to run some logs this weekend and try and find the issue, i just need advice on what to specifically to log and what to look for upon review.

oh, custom exhaust (after downpipe, still stock), internals, intake, and some colorful hoses. that's it.

thanks in advance.

Just log everything and post em up.

excuse my n00bness, but is there an easy way to do that on the ap?

in my limited experience, it looks like it will only let me log one variable at a time.

EDIT: i got it. i'll post logs when i have them

It's in the menu under logged parameters or something like that. Select everything.

Any other mods?

nah..

just the intake, test pipe, resonator delete, fuel pump internals, and my uncle got me a blue recirc hose. i've got lowering springs too, but i doubt that has anything to do with the problem. ha.

Edit: JBR dog bone, and JBR rear sway bar.

sorry for the delay. i got swamped this weekend unexpectedly. i attached the log of a 3rd and 4th gear run. definitely was happening most of the way through. i am currently running the stage 1 tune for corksport intake and turbo inlet on 93.

any help is greatly appreciated.

You messed up your internals, see line 47 of your log. Fuel pressure drops to 568 when it should still be 1600+.


Also, go search for the list of params to log...you have too much turned on so your logging rate is horrible and can miss things.

ok. i'll crack it back open and see if i can find the problem. thanks for the help!

Definitely can't hurt to double check your install for that pressure drop.

Another issue that stands out is your mass air flow, and MAF voltage numbers. Instead of increasing in a linear fashion they jump around erratically. Check the wiring, gasket, and ensure your MAF sensor is totally clean.

yeah, i'll definitely check it out. thanks for the heads up.

i don't have excel at the house, so i just opened up that file here at the office.

what's confusing is that the surging was occurring in 3rd AND 4th. the shift seems to happen at line 33, but there is no indication that the fuel pressure dropped like in line 47 as mentioned.

i'm going to do another log with fewer parameters and see if it shows up. again, thanks for all the help.

You can download OpenOffice, LibreOffice, etc, for free and view your logs at home. No need to give money to Micro$oft.

I'd investigate trying to improve your sampling rate first and get some confirmation of the problem. Right now you're only logging like 8-10 pts/second. For example at that one point at 5000 RPM where your fuel pressure drops to 500, there’s nothing on either side of that single point confirming the “bad” value, all you know is that it occurred somewhere in that 0.4 second window between the last point and the point after it, which is a really long time. Try disabling some of the less useful stuff like accelerator pedal position, coolant temp, battery voltage, etc. Also, disable traction control during logs if you aren't already. One thing that looks odd to me is how your pressure stays high after you let off at the end of the log, even though the ECU is clearly commanding a lower pressure. Maybe others can chime in with regards to whether this indicates a potential problem with the electronic spill valve, because if it does, you should try cleaning it when you remove the fuel pump to inspect the internals (not to worry, this is quite easy, the E85 guys do it regularly).

I'm inclined to agree that the cell where pressure drops to 568 psi is just a logging anomaly. The rest of the log where load and boost are at their highest, the pressure holds just fine.

That being said, it still can't hurt to rule out mechanical issues related to HPFP.

had some time at lunch to try again. i reset the ap to it's standard values, but i made sure all the items involving the hpfp were checked.

and, of course, it didn't happen. i'm going to upload these anyway so anyone who wants to can take a look, but i'll try again later.

Well, that 4th gear log doesn't look good in terms of fuel pressure.

http://i.imgur.com/68irHyW.png

Dropping into the triple digits at peak load values is not good.

You need to start troubleshooting your HPFP. Your relief valve may be failing.

did a search here and i'll do the relief valve test tonight when i get home. the maf seemed to straighten itself out though. did you notice anything else?

When my HPFP started looking like that, my injector seals went to shit.

got back to the house, car was warm, cut it off, waited a minute, put the key back in the "on" position and looked at the fuel pressure.

started at 500 and climbed up to 1300....

all the stuff i saw this afternoon was talking about it being at 60. any ideas?

Relief valve is good then, time to look under the IM for leaking seals.

you don't think i should break down the pump and make sure everything checks out with it first?

Go for it, why not, considering it takes little time.

i'll probably do that this weekend. in the meantime, i'm going to go back to the stage 0 map just to be on the safe side. thanks for all the help. i'll update this thread after i get under the hood.

pulled the pump apart yesterday. everything looks fine. no leaks, everything appears to be functioning as it should.

so... injector seals?

any other ideas?

as i was reading another thread to try and determine if the seals are the issue, i remembered that i did put in one step colder plugs. the ngk itv22s. just offering up this as another piece incase anyone has any other ideas.

Spark plugs have nothing to do with low fuel pressure.

As @Code Monkey; suggested, you probably have an injector seal issue.

Notice any odd sounds? The seals will usually make a popping sound when failing.

You may also be able to see fuel residue dripping down from a leaky injector.

http://www.mazdaspeedforums.org/foru...removal-73170/

http://www.mazdaspeedforums.org/foru...-delete-78250/

from everything i read this afternoon, i'm guessing that's the issue. what everyone else has described is really close to what is happening. honestly, i was just hoping for confirmation before i committed to replacing them.

thanks for the help.

To add to this. I am having the exact same problem. I changed the relief valve and restored my fuel pressure after shutting off (relief valve failure symptoms - and yes it was failing). Dips were still there so after peeking around the manifold I saw one crows foot covered completely black along with part of the rail connecting to injector number 3. Long story short I ordered cp-e seals. I'm pretty sure the seals are shot


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cool. thanks for the heads up man. looks like i'm going to be replacing them here in the near future. any reason you went with cp-e over the toyota seals?

The Toyota seals are a bit of a temporary solution. They are cheap as hell compared to aftermarket, but they do not tend to last a long time. They eventually crush to the point of allowing injectors to leak/rattle again. Some people have had long term luck with them, but other people have had to replace them again in about a year.

^^ what he said. You can also go with corksport ones which are also a crush one time design. Cp-e comes with the studs, nuts and washers to replace the torx bolts since their design seems to need more clamping force. But to each its own rallysport direct is selling cp-e ones for the same price as corksport


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Sounds like a possible lean condition.. And I hope you haven't damaged your motor.
That being said get an AEM UEGO or something along those lines that's highly visible when your doing these tests.. That way you know on the fly if its running lean rather than checking your %%$ after the fact.

That being said could be several things.. Boost leak/etc however since you said your fuel pressure is dropping sounds like the above mentioned

Ok guys. My car was all sorts of fucked up so this was a tough fix for me. I have put a new relief valve. New injector seals and now i have put a whole new HPFP. And the dips are there. Any advice or help is appreciated. I cant figure out what the hell is going on. I'll attach my new datalogs... These are all third gear logs.. As for the mods. I'll list the below.

Cobb intake, TIP, Front mount and downpipe to a Triton Exhaust. cp-e HPFP