Fuel Pump failure?
 

I've had my FullBlown turbo kit for just over a year now and its been great. The past week my car has developed a starting problem (5 cranks). Logs show the MAF is clean, MAP is on key A/F seems to be swinging a lot. When the A/F is going crazy the cars voltage drops from a health 14.2v to a 12v. At the same time the car runs like shit when this occurs.

I tried to call Full Blown but its Happy Monday and i'm sure they are busy and didn't pickup.

Is it intermittent? Is it any different if you're cruising on WOT? Does the AFR go lean or is it swinging lean/rich?

It's not so bad when driving above 3k RPM's but at low RPM's it tends to swing a lot. The car is also also adjusting the fuel trim when this happens from 3% to 17% swings.

WOT it doesn't feel like it has the balls as much either but that could be me getting used to boost.

1 last thing. I don't have anything from ebay or any electronics installed but my AEM failsafe.

If you're able to get into boost WOT, and the car is not leaning out, it does not seem to be the FP.

AFR holds good while WOT?

Since drivability is the most affected, I vote for a vacuum leak. Did you clamp the hoses under the intake manifold?

Other thing to check is for faulty injector connector or faulty injector itself.

No Lean out or boost creep. Car holds a strong 7.8PSI with WOT and A/F is 11. No check engine or codes stored in the ECU.

All the lines under the hood are clamped including the evap lines. If it was a line I clamped that pig.

I am actually having a similar issue. Just installed Injectors, Flex-Fuel, and EBCS.

WOT fueling looks great, but normal driving short term fuel trims get maxed out. Triple checked all the lines, every line is clamped tight. I even tried doing a boost leak test with no leaks detected. Tuner doesn't see anything wrong in the logs besides fueling. Thinking a bad injector possibly.

In for results.

I don't believe its a boost or vacuum leak. I don't get boost creep and vacuum is holding a steady -19 at idle with AC off and -17 with AC on. even with the A/F going a little crazy the idle RPM is 900 and the only thing I see is the voltage following the hiccups. the high pressure fuel pump sensor also is steady and doesn't seem to show a drop in PSI when the car does this either.

I can be at 2500 RPM's and watch my voltage drop to 12v and then back up to 14.2v, The voltage drop is following the damn hiccups for sure. only pattern i've found.

I will check mine as well. Possible battery going dead?

Edit: Battery shouldn't mess with voltage as the alternator should take care of it, couldn't hurt to check though.

I actually noticed a drop in vacuum switching from OFT to ECUtek. That is why I questioned vacuum leak.

I don't have a vented hood and Its summer down here in florida. I wouldn't be surprised to see the heat killed it. I'm pulling my alternator to have it tested.

Damn it. Found this while I'm at work before I can pull my alternator when I get off.

http://www.ft86club.com/forums/showthread.php?p=880249

http://www.ft86club.com/forums/showthread.php?t=88871

This one showed some high fuel trims with a battery that eventually died. Replaced the battery and the issues went away. I'll try swapping batteries at lunch.

Battery and alternator tested good. Only other thing I can think of is since all my evap lines are clamped is. What if my evap isn't closing all the way and I'm boosting my tank. Will that affect my fuel pressure or put stress on the pump? For the time being I plugged the line from the evap and left my tank breather open so it can breathe.

Interested to see where this goes...

My fuel pump died/ not pushing 60psi, BRZ/FRS fuel line needs to be at 60psi, if it is not you might need to check your fuel system.

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