MSPNP cutting out fuel at various loads - Miata Turbo Forum - Boost cars, acquire cats.

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Old 07-11-2008, 09:44 PM   #1
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Default MSPNP cutting out fuel at various loads

Okay so I thought I had it licked. I turned off the OVERRUN settings and that solved my cutting out issue before.Now it seems like something is killing my juice. I replaced the battery and alternator but something is killing them. After a full battery charge on a new battery and good alternator, the car runs fine. After a while running on the road, say 10 minutes, it starts to shut off my fuel at certain rpms while in gear. Out of gear it revs fine. What the heck is going on?


*MSPNP9093 w/boost, no AFM*
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Old 07-11-2008, 10:06 PM   #2
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may be unrelated to ms, have you logged these occurances.
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Old 07-12-2008, 04:33 PM   #3
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you HAVE to post a .msq or else no-one can help you.
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Old 07-14-2008, 10:11 AM   #4
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A data log would also help. You can even see the battery voltage in the data log which will be helpful diagnosing the charging system.
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Old 07-16-2008, 02:14 PM   #5
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well the charging system is fine according to the REAL TIME Display. I took it for a little spin down the street. It runs great at first, then it starts to cut out and I let up a bit and then it comes back. This is through all the gears, again when in neutral it revs fine.
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Old 07-16-2008, 02:52 PM   #6
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By "cuts out" you mean it runs lean & sputters, or something else? Does it accelerate fine if you romp on it? Could be that your VE table is just lean as **** in the part throttle cells. Have you ever tuned it and did it ever run well when warmed up?

There are plenty of people on this board who are completely fluent in the ways of Megasquirt (not me) but you have to give them something to work with.

POST A LOG AND YOUR MSQ.


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Old 07-16-2008, 06:30 PM   #7
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By "cutting out" I mean that it feels like its cutting fuel...no power. Sure, it sputters into it and out of it, but it goes out like a flashlight and when I let go it regains its normal way. I will post my .msq tonite* If I'm allowed back into the garage( you married guys know what I mean).
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Old 07-17-2008, 01:26 AM   #8
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Quote:
Originally Posted by hazimwood View Post
If I'm allowed back into the garage( you married guys know what I mean).
All to well...


Anyway, dude def post a log/msq so these guys can help you rule out MS related issues... fwiw, with all the quirks my car has, i'd be dead lost without a wb02...u might wanna invest in an Lc-1 or AEM Uego...

Also, like I mentioned your symptoms sounds similar to mine, when my fuel pump took a dump on me...
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Old 07-30-2008, 09:58 PM   #9
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Here is my setup. The datalog is me backing out of the garage, getting on the road and trying to get the car to move, but it was really bad. I had just replaced the fuel pump and everything was going fine, but I believe some rust is screwing me up and clogged a couple of injectors.

Let me know what you think of the actual problem of the engine cutting out around 60-70 KPA (a guess while looking at the laptop while running).

what is wierd is that I took the car out while it was still cold and got into boost (about 6-7psi) and it ran fine for those few minutes that it was cold. I am guessing that the problem lies in the naroowband O2 or some KPA-related function.
Attached Files
File Type: msq MSPNPJuly162008.msq (35.1 KB, 60 views)
File Type: xls datalog1.xls (337.5 KB, 70 views)
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Old 07-31-2008, 12:16 AM   #10
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Battery voltage looks OK in the log and the pulsewidths never went below 1.6

This log doesn't show you ever hitting boost. Do you always let off the throttle when it cuts?
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Old 07-31-2008, 09:31 PM   #11
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Quote:
Originally Posted by compy View Post
Battery voltage looks OK in the log and the pulsewidths never went below 1.6

This log doesn't show you ever hitting boost. Do you always let off the throttle when it cuts?
It will not let me hit boost when its going through its thing...only when its cold. I dont always let off, but I find it especially frustrating to keep pushing it when it doesn't want to go.

Any answers anyone?
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Old 12-01-2008, 12:06 PM   #12
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Problem Fixed!!

Turns out that my fuel tank was completely rusted over, causing my new fuel pump and filter to get clogged, not to mention the injectors. I replaced the Tank with a a bigger 1994 unit and everything is running great now. Also my spark plugs were fouled and along with that the car is great now. I could literally scoop out piles of rust with my hand. Very nasty.
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Old 12-01-2008, 12:22 PM   #13
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crazy
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Old 12-01-2008, 07:12 PM   #14
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please do not post pics of the rusty fuel tank.
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Old 12-06-2008, 11:21 AM   #15
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here ya go:
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