Boost w/o MAF, no boost w/ MAF, bad MAF?

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tsbpenguin
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Location: Denver

Boost w/o MAF, no boost w/ MAF, bad MAF?

Post by tsbpenguin »

Got the ej22t swap back on the road today and it is acting funky. With MAF plugged in it it will start and idle fine, and starts to pull from a stop just fine but once the vacuum starts to creep towards 0 boost, the car sputters, hesitates, and won't accelerate or build any boost at all. If I unplug the MAF, the car starts, but will die at idle if I don't keep the rpm's up. Once on the road, it starts to pull, hesitates and sputters a bit around 0 boost, but if i stay on it it stops sputtering at about 5psi, builds full boost (MBC set at 10) and feels like it is pulling great. No engine codes at all (except when I unplug the MAF and then of course it throws a MAF code.) Sound like a bad MAF, or is there anything else I should check first? Thanks!
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tsbpenguin
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Posts: 109
Joined: Sun Sep 23, 2007 11:22 am
Location: Denver

Re: Boost w/o MAF, no boost w/ MAF, bad MAF?

Post by tsbpenguin »

Took it for another road test and wanted to clarify what happens when the MAF is unplugged. I still can't go WOT right away, it will cut out at 0 boost, but if I go part throttle until it starts to build boost, then I can go WOT and it will fully boost and pull. This makes me think it's not the MAF but maybe pressure exchange solenoid? Just seems like it's having a really hard time switching out of vacuum into boost.
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cj91legss
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Re: Boost w/o MAF, no boost w/ MAF, bad MAF?

Post by cj91legss »

If you happen to need a new maf, I have one for sale. Have you checked the vacuum diagram in the stickies? You could have a line backwards somewhere or not hooked up at all. If you also happen to need a wastegate solenoid or pressure exchange solenoid, i have those for sale as well.
91 L-TW Wagon with a full Swap -RIP
92 SS Prefaced, GD dash swapped, 22T/205 Hybrid 20 psi - BEAST!
93 SS Bone Stock Gone!
94 TW Bone Stock Gone!
91 SS 4EAT Sold!
98 LGT 4EAT
98 LGT Wagon 4EAT
Alphius
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Re: Boost w/o MAF, no boost w/ MAF, bad MAF?

Post by Alphius »

Do you have a check engine light or any codes stored by the ECU?
tsbpenguin
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Posts: 109
Joined: Sun Sep 23, 2007 11:22 am
Location: Denver

Re: Boost w/o MAF, no boost w/ MAF, bad MAF?

Post by tsbpenguin »

Not sure how I didn't notice it before, but ended up being that the driver's side fuel rail had no bolts, and thus nothing holding it down. Fixed that, tightened up a couple intake clamps, and voila she runs like a champ. Boost feels great :D
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cj91legss
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Re: Boost w/o MAF, no boost w/ MAF, bad MAF?

Post by cj91legss »

Awesome!!!

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91 L-TW Wagon with a full Swap -RIP
92 SS Prefaced, GD dash swapped, 22T/205 Hybrid 20 psi - BEAST!
93 SS Bone Stock Gone!
94 TW Bone Stock Gone!
91 SS 4EAT Sold!
98 LGT 4EAT
98 LGT Wagon 4EAT
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