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Hesitating on boost??

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Old 28 December 2009 | 10:33 PM
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Question Hesitating on boost??

I seem to have developed a slight hesisating problem when i am booting it,

i doesnt seem to be boost right up. any ideas?

its going in to MOCOM on thur just thought i would give a heads up on here

Thanks

darcy
Old 28 December 2009 | 11:15 PM
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Originally Posted by Darc174
any ideas?
Going on the information you've given us, no.
Old 28 December 2009 | 11:52 PM
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Originally Posted by Splitpin
Going on the information you've given us, no.
Splitpin: Blunt and to the point as usual
Old 28 December 2009 | 11:55 PM
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Splitpin fairly cracks me up. He posts what others are thinking too... but who are afraid to post, for fear of being flamed by the OP.
Old 29 December 2009 | 12:22 AM
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What much can i say Apart from what i have "STATED"

feels like its holding back or maybe miss fireing
Old 29 December 2009 | 12:39 AM
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coil packs ?
Old 29 December 2009 | 02:23 AM
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Done a search? Any CEL or Fault codes? Usually MAF or dodgy coilpack/lead's

https://www.scoobynet.com/general-te...ting-help.html
Old 29 December 2009 | 11:13 AM
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Originally Posted by b13bat
Splitpin: Blunt and to the point as usual
what is he like??

possible spark plugs,vacuum leak maybe?
Old 29 December 2009 | 11:15 AM
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Originally Posted by Splitpin
Going on the information you've given us, no.
very helpfull indeed!
Old 29 December 2009 | 11:17 AM
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Probably overboosting but no mention of when it started or modifications so having a guess as my crystal ***** have frozen

Tony

PS more info is required, does it do it in gear? mods, when it started etc

Last edited by TonyBurns; 29 December 2009 at 11:18 AM.
Old 29 December 2009 | 12:19 PM
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Originally Posted by 99greenwagon
...spark plugs...
Old 29 December 2009 | 12:26 PM
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mods are in my garage its just had the plugs and new maf, so im kinda taking it its none of them. its going to mocom so they can run some checks as im lost, could be coilpacks but would it not do it all the time?

darc
Old 29 December 2009 | 12:36 PM
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What does your boost gauge say?
Still unsure when this started? during the very cold spell?
Still could be overboosting rather than anything else, but you have not said when its happening? is it in like 4th and 5th gear? 2nd gear? 1st gear??
More info please.

Tony
Old 29 December 2009 | 12:39 PM
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Originally Posted by 99greenwagon
what is he like??
Honest. If posters can't be arsed (or don't know how) to provide basic pertinent info that actually helps us help them, then I'm happy to leave you lot to chase your tails making uneducated guesses.

Darc: Seeing as it's you who wants us to help you solve your problem, simple logic suggests you should make it as easy as possible for us to do so, which means posting any pertinent details re. your car, mods and stuff in your post. Expecting us to go running round looking for information elsewhere is taking the p*ss and ultimately reduces the chance of you getting good info in return.

For example, you've just told us that "mods are in your garage". Why wasn't that statement, and a direct link to your garage, part of your original post, or the second? See what I mean?

We still don't know, for example, what type and MY your car is, and exactly how it feels. Your initial post isn't that clear as you describe "hesitation", and then that it "doesn't seem to boost right up". Are you basing this on feel or a glance at a boost gauge? Is it something that applies all the time you've got your foot down, or does it clear? Tell us more.
Old 29 December 2009 | 12:47 PM
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Guys sorry to jump on the thread, my RB5 is doing exactly the same thing, when in 5th gear with WOT the turbo spools up then releases, then spools up again ( with my foot planted into the carpet ) The Boost gauge reads 1.5 then up to 2.0 then back down to 1.5 as if I'm pumping the pedal but very slowly.
it only does this in 5th gear. Been told its the turbo hitting a 'boost wall' but how true or how much bull crap that is i don't know.
Old 29 December 2009 | 01:07 PM
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Originally Posted by SiV6Si
Guys sorry to jump on the thread, my RB5 is doing exactly the same thing, when in 5th gear with WOT the turbo spools up then releases, then spools up again ( with my foot planted into the carpet ) The Boost gauge reads 1.5 then up to 2.0 then back down to 1.5 as if I'm pumping the pedal but very slowly.
it only does this in 5th gear. Been told its the turbo hitting a 'boost wall' but how true or how much bull crap that is i don't know.
See Darc, this is better, much more detail than your OP. ^^

Si, further questions: These boost gauge readings, can you double check them or confirm what units you're quoting? If it's bar, you are waaaaay above where an RB5 should be. Is it possible you're misreading the gauge and you actually mean 15psi up to 20 then back down to 15? This would make more immediate sense.

Also, can you confirm whether you're still running the original two port boost control solenoid, whether it's standard turbo/boost target or not, and whether, when the boost drops, you're getting a sudden "cut" in engine power, like the brakes have been stabbed very sharply?

This has all the hallmarks of overboost and consequent oscillation due to oiled up control pipework, modifications rendering the restrictor too small, or something along that axis. As per above, the more info you give us, the easier it is to advise you.
Old 29 December 2009 | 01:15 PM
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sorry my mistake its 1.0 to 1.5 BAR ( i Wish it was 2.0 LOL )
Also, can you confirm whether you're still running the original two port boost control solenoid, whether it's standard turbo/boost target or not, and whether, when the boost drops, you're getting a sudden "cut" in engine power, like the brakes have been stabbed very sharply?
not sure on the solenoid, the car is running the STD turbo / TMIC combo.
It has Scoobysport decat and full system, the engine runs fine if i use Half open throttle.
It doesn't feel like the brakes have been put on suddenly ( it did this syndrome before the MAF was replaced )

The car pulls away fine then pauses i.e. boost drops, then spools back up again.

The car was running a FMIC and a non OEM ECU combo and a VF23 but all had been removed before i bought it.... could this be a problem ?
Old 29 December 2009 | 01:32 PM
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Originally Posted by SiV6Si
sorry my mistake its 1.0 to 1.5 BAR ( i Wish it was 2.0 LOL )
No you don't, not on that turbo.

If it's going anywhere near 1.5 bar, something is "up".

It doesn't feel like the brakes have been put on suddenly
No fuel cut then.

The car was running a FMIC and a non OEM ECU combo and a VF23 but all had been removed before i bought it.... could this be a problem ?
It might be part of the explanation, yes. Your boost gauge numbers still don't add up, assuming that you now have a standard RB5 (AE801) ECU fitted. This could be because of oiled up boost control pipework, but given what you've said, it's also possible that the boost control system was modified to suit the previous ECU and turbo, and was not properly returned to standard when the OEM stuff was fitted back in.

The one thing that is still confusing is the fact that you say it's hitting 1.5 bar. Are you absolutely sure about that? Fuel cut on the standard MY99 ECUs is 1.22 bar - so if you're quoting from your gauge correctly, either it is wildly exaggerating, you don't have a standard ECU, or there's something wrong with the MAP sensor.

Have you ever looked at the ECU? If so, do you know what colour the sticker is? Also, can you look at the boost control solenoid and tell us whether or not it's standard - or post up a photo of it? Standard one should be a turquoise-blue plastic cylinder with two pipes sticking out the bottom and an electrical connector at the top.
Old 29 December 2009 | 02:50 PM
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ok NEWB ALERT

Where is the ECU, also where is the Boost controller.

Now that you have mentioned the boost won't go above 1.22 bar, this may shed some light on the problem, as mine seems to be hitting 1.22 bar then releasing.

YouTube - Rb5 fluctuate

sorry about the bouncing and quality - taken using my iPhone.
Old 29 December 2009 | 04:09 PM
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ok maybe my mistake i thought the "view garage" tab was to view the spec of peoples Cars.

anyway its a MY00 (uk) Car

mods

3 Inch Open Mouth De-Cat Downpipe
Full 3 Inch Blitz Nur spec R System
TD05 Turbo
Newage STI Topmount Intercooler
STI 7 Scoop
STI V7/8 Intercooler Undertray
K&N Cold Air Induction kit
Samco Blue Silicon Hose Kit
Lightweight Race Flywheel
"Pink box" Exedy Racing Clutch
Walbro 255 fuel Pump
APEXI POWER FC
REMAPPED BY MOCOM RACING!

Basicly when im in 4th and 5th and i plant my foot it boosts up fine up to 1.15 then starts to hesistate but holds the 1.15 bar, but my boost is set to 1.3 so its not boosting right up, (maybe could be my boost solinoid???) not sure.

if im in 1st 2nd 3rd and plant my foot i cant seem to feel it as much as i dont normaly hit 1.3 bar till abit up the rev range.

it doesnt feel like a misfire and its only started happening since the cold spell.

Hope that helps more

Darc
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