hesitation issues

[ride_child]

so ive been chasing this hesitation issue for awhile now. ive got a new alternator, new plugs, great wires, been through a couple different coil packs, and all pre and post turbo hose are tight and leak free. one thing that ive noticed recently is that at work, my car drives awesome and pulls hard like it should, but down in town, the hesitation comes back, its clockwork. i work at crystal mtn, about 4400 ft and its been pretty cold lately. i know the ecu/map/maf adjusts for altitude and temp. so seeing as thats my most viable option because ive gone through the rest of the probable culprits, do you think one of them could be messed up (ecu/map/maf)?

[wtdash]

If the car has ever stalled while driving and you have the hesitation, I'd try another MAF. The stock turbo MAFs aren't as plentiful as the plastic/green label version. If you didn't know, the '90-'91 NA 5-speeds had the same Hitachi MAF as the '91-'94 Turbo versions. Or just clean yours w/MAF cleaner. I've read not to use anything else as it may be too harsh on the filament.

GL,
TD

[ride_child]

it has never been bad enough to stall it, not even close. its like when i step on the gas, the boost goes up but it takes a second to kick in. i know youre probably thinkin boost lag but this is worse. it reminds me of a dog tryin to turn a corner while running on hardwood floors if that makes sense. i have a z4 for it, all im waiting for is the adapter from rob and to get my 440's flow tested, along with that as im sure you know ill be putting in a jecs maf so maybe that will cure it. but i dunno im almost stumped here haha

[kimokalihi]

Do the rpms go up but not your speed? You sure its not the clutch slipping? Also, have you checked for codes stored in the ecu?

[ride_child]

yea the clutch is not slipping, i put in a new clutch probably about 30k miles ago, and ive experienced that, definitely not the clutch. and i have checked for codes, there arent any... thanks guys i really appreciate the input!!

[kimokalihi]

Shot in the dark but you could try adjusting your tps idle switch. I was having hesitation problems and it was my idle switch. The tps was so far out of adjustment for the idle switch that the switch was telling the ecu that the throttle was in idle position and cutting fuel.

[wtdash]

So..it's a 'boost' hesitation only? I was thinking just general drivability hesitation....Hmmm

[ride_child]

thanks kimo ill look into that.

wtdash, i only attribute it to the boost because i have a boost gauge and when i go half or more throttle, i can watch the boost climb, and it will sort of stutter for a 1000 or so rpms then pulls hard. when it doesnt do this, i can watch the boost climb and feel the car pull harder in unison, theres no disrupt.

[cj91legss]

Kris this is the exact same b.s. I've been dealing with for awhile now. I've swapped maf, fuel pump, check/re-timed, swapped new plugs, re-gapped plugs.....

[ride_child]

cj you should come up to crystal or maybe snoqualmie and see if being at altitude/colder temps has any affect on your issues.... cause its the weirdest thing, mine drives like a champ up here haha

[cj91legss]

The first morning it was 21 degrees here, felt like I had extra HP and had no hesitation.

[ride_child]

Then it has to be something the temp affects because its been steadily that cold up here.

[Legacy777]

Have you tried new coolant temp sensor?

Regarding altitude, the MAP sensor measures atmospheric/altitude changes via the pressure exchange solenoid. Connect only the green connectors and put the ignition in the ON position. All the relays and fans will cycle on and off. Make sure the pressure exchange solenoid is cycling. Regarding the MAP sensor, you can test it via these instructions:

http://www.main.experiencetherave.com/s ... sensor.jpg

[cj91legss]

Yes both he and I have done coolant temp sensors. I swapped his the last time he was at my house.

[ride_child]

now my car wont start or hold a charge at all... fucking fantastic.

[wtdash]

Battery check? Don't want to get your hopes up too much, but I have read where a dying battery can cause similar hesitation issues.
Td

[ride_child]

well i do have a yellow top i do need to warranty haha but as far as my car not starting or holding a charge, im pretty sure my alternator i just put in is burnt out... awesome!

[cj91legss]

That sucks.

As far as hesitation, I have a new battery and new alt.

Sent from my SGH-T889 using Tapatalk

[ride_child]

anybody know what year/model alternator will work with a slightly higher amperage? i have a lot of electronics in my car and just want to account for the extra load.

did that work cj?!

[cj91legss]

No it did not. I think there is a thread about a tribeca alternator on here.

Sent from my SGH-T889 using Tapatalk

[ride_child]

yea i have that z4 im gunna put in so we will see if that does anything. and i want to get a new coil pack too. other than that im pretty stumped.

[Legacy777]

You can run the 02+ WRX and most likely other newer EJ series alternators. You just have to convert from the older 3-wire plug to the newer 2 wirer plug.

[ride_child]

oh ok saweet! and incase anyone was wondering, it was my "new" alternator that burnt out, shes running fine again, still with that hesitation tho

[alexandermf]

I have the same hesitation... Never had it before, just recently started! Its like I watch the boost gauge go up but the car feels like its holding itself back and sometimes ill get spurts of no hesitation. But wot it almost feels as bad as limp mode... I got some cel codes on (vss, inhibitor switch, neutral switch) from my manual swap but none of those should be causing this hesitation. I'm stumped, its frustrating

[robertpaige]

I had the same hesitation on boost.. I could never figure it out. It would be almost shaky under boost. Something that seemed to help boost come on smooth was when I swapped out my straight downpipe for a downpipe with a resonator. Idk why that seemed to make everything smoother, but it did. Food for thought. My setup was 14psi on TD04.