hesitation under boost at full throttle

[shane]

this may have been asked, but i didn't find anything in Search, so here goes.. 1991 GTS4 with the RB20 has bad hesitation under full throttle acceleration. But, when i push the throttle slower, it seems fine. I dont' have a boost gauge, so i don't know if i'm losing boost, but I'm wondering if anyone else has run into this, and what the solution may have been. I haven't done a tune up yet, either, so i know that's a possibility.

[klys]

misfire due to spark plugs with too much gap.

regap them to around .8mm or ~30 SAE

[gtr4life]

I would be guessing your Throttle position sensor or maf.

i know when my maf was dirty under full throttle it would hesitate then go.
every shift.

[sidewazegtsr]

^^^

Both you guys could be right on this.

I'd suggest the following trouble shooting options to do,

1. Check your plugs and the gap on them. Running higher then 10psi they have to gapped at 0.8mm to ensure you don't get blow out in the higher rpms.

2. Check the resistence on your coilpacks, they should read between 07.09 Ohms.

3. Make sure your fuel filter good.

4. Clean the MAF even with just a spray cleaner.

5. Make sure your timing is correct.

6. Check the TPS (i have'nt done this personally and im not familiar with how to do it) see that it's working properly.

I know it's a lot of crap to do but thats the thing when it comes to trouble shooting, you gotta do all this in order to find out what exactly the problem is.

Good luck and let us know if you need anything else.

Cheers 8)

[shane]

Thanks, all. this is my first turbo car, so i'm still learning.

[SmegEad]

6. Check the TPS (i have'nt done this personally and im not familiar with how to do it) see that it's working properly.

Don't forget, we're using the new coversheet on the TPS reports now. Didn't you get the memo?

^ Obscure 'Office Space' reference


PS: I'm sorry - I know it's completely off topic, but I really couldn't resist. I tried to fight the urge...but hey. Sorry JZ et al.

[James Mramor]

Check the coils too... they are prone to not working right!

So you got lotsa stuff to check out. let us know your findings

[BigBlueR32]

I would put money on the MAF being your main problem.. if there is anyone in your area that you can swap to confirm it that would be sweet..

When that MAF is just starting to go you will be able to rev freely when in neutral but under load it will just stutter and have no power at all..

[shane]

I would put money on the MAF being your main problem.. if there is anyone in your area that you can swap to confirm it that would be sweet..

When that MAF is just starting to go you will be able to rev freely when in neutral but under load it will just stutter and have no power at all..

would it be worth the money to just swap in a MAF from a Z32? The car currently has a 3" exhaust from the turbo back with no cats in it, and a K&N drop in filter. To my knowledge those are the only engine mods.....

[sidewazegtsr]

^^^

If you swap to a Z32 MAF you'll need either an SAFC or ECU tune in order to use it.

Honestly man do all those trouble shooting methods first, then evaluate the situation after that. I mean you could swap the MAF and still have the same problem. You need to figure out exactly what it is first before spending money where you don't have to. Only a suggestion.

[Stevo_323]

hey my skyline sorta does the same, this is my first turbo car so im not sure, but it seems like up to 3000rpm it lags then once it hits 3000 it explodes, like, my gf's stock crx beat my skyline off the line untill i hit 3000rpm. and it seems to do this in all the gears

think its the same problem?

[sidewazegtsr]

^^^

Well that's pretty much my issue too. After I clean my MAF this weekend I'll let ya know and you can try it for you car.

[BigBlueR32]

hey my skyline sorta does the same, this is my first turbo car so im not sure, but it seems like up to 3000rpm it lags then once it hits 3000 it explodes, like, my gf's stock crx beat my skyline off the line untill i hit 3000rpm. and it seems to do this in all the gears

think its the same problem?

Sounds like boost lag to me.. hehe.. would need to feel what you mean exactly.. :P

[Stevo_323]

yea another guy i asked said it was turbo lag also, i figured it was, but then i saw this thread and wondered.

[Endless604]

^ im having this issue too. lags like ughhh until it hits 3200rpm

so much more noticeable during these scorching hot days