i recently fitted an evo 4 engine/gearbox etc to my cm5a gsr.everythings working grand except when i really drive it hard and it gets to about 4 and a half k revs,pedal to the floor...then the car shudders and jerks with no more acceleration.
first i thought it was a boost leak,then i thought the hks dump valve was upsetting the maf.
theres 2 others im more inclined to think it could be,either the fuel pump isnt able for it,(but its a new walboro) or else the boost is spiking which would tell the ecu to cut fuel i think? can anybody shed some light on what it could be? thanks in advance
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#1
Posted 02 August 2011 - 02:59 PM
richie k
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#2
Posted 02 August 2011 - 09:03 PM
bazeng
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Gday maaaate
- LocationMelbourne
Get a fuel pressure guage and wide band to diagnose.
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#3
Posted 03 August 2011 - 08:19 AM
Lister
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#4
Posted 03 August 2011 - 11:00 AM
BMGTZ
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Grumpy old man from the school of hard knocks
- Locationsouthside of perth WA
symptoms certainly point at boost leak......Have you tested it? leak testers off ebay are pretty good
BRIAN
Black evo 1 full road rego and done properly/legally
I have heaps of parts...but never the one I need.
#5
Posted 03 August 2011 - 01:32 PM
richie k
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dont think its a boost leak cos im able to accelerate straight away again after it jerks,would a leak be constant? couldnt spot a leak but havnt tested it.
if it was plugs or coils it would happen up through the revs at even half throttle but its only when flat out at high revs. not sure about tps tho.
hadnt thought bout fuel pressure.
im so broke after doing the conversion im goin to have to wait a bit
when i can afford a boost gauge and fuel pressure gauge il fit him them and see.hopefully soon.if it is spiking it could be actuator problems.
if it was plugs or coils it would happen up through the revs at even half throttle but its only when flat out at high revs. not sure about tps tho.
hadnt thought bout fuel pressure.
im so broke after doing the conversion im goin to have to wait a bit
when i can afford a boost gauge and fuel pressure gauge il fit him them and see.hopefully soon.if it is spiking it could be actuator problems.
#6
Posted 04 August 2011 - 12:15 AM
TMAK
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Formerly known as FRONTN
- LocationHillside, Victoria
Is it a violent jerk?
Can you reach redline with like half throttle?
Can you reach redline with like half throttle?
TMAK - JDM Evo 6.5 TME White with stripes - burnzytuned
|MAP shortblock 2.4LR 10.5:1CR|MAP EF3|GSC S2|Ohlins coilovers|Cusco|Endless|Meek|Turbosmart|Spoolin Up|Bosch 2000|Walbro 400|Zeitronix|GM|Kumho|Stock ported intake and exhaust manifolds|
366kws (vdr) @ 2.1bar
Old setup: 280kws (vdr) @ 24psi [email protected]
Previously owned the FRONTN Cordia.
|MAP shortblock 2.4LR 10.5:1CR|MAP EF3|GSC S2|Ohlins coilovers|Cusco|Endless|Meek|Turbosmart|Spoolin Up|Bosch 2000|Walbro 400|Zeitronix|GM|Kumho|Stock ported intake and exhaust manifolds|
366kws (vdr) @ 2.1bar
Old setup: 280kws (vdr) @ 24psi [email protected]
Previously owned the FRONTN Cordia.
#7
Posted 04 August 2011 - 03:38 PM
richie k
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ya its quite violent,scared the shite out of me the first timeIs it a violent jerk?
Can you reach redline with like half throttle?
i tried it there and i can reach reline at half throttle,it seems to only happen under aggressive driving
#8
Posted 05 August 2011 - 12:40 AM
Chaser
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tits and arse man
- LocationCessnock NSW
Check the plug leads mate, good chance that 1 is earthing out. I had the same problem a few months back the leads were shorting out causing it to break down and miss fire very bad. Pull the leads out and wrap them with electrical tape and see it goes away. Also check the plugs four burn marks down the side (little black marks) that will give you a good indication if that is your problem.
slowest cc coupe in the build
#9
Posted 05 August 2011 - 08:02 AM
TMAK
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Formerly known as FRONTN
- LocationHillside, Victoria
Sounds like boost cut to me.
Maybe put in an ecu from 5-8 and get it flashed.
Maybe put in an ecu from 5-8 and get it flashed.
TMAK - JDM Evo 6.5 TME White with stripes - burnzytuned
|MAP shortblock 2.4LR 10.5:1CR|MAP EF3|GSC S2|Ohlins coilovers|Cusco|Endless|Meek|Turbosmart|Spoolin Up|Bosch 2000|Walbro 400|Zeitronix|GM|Kumho|Stock ported intake and exhaust manifolds|
366kws (vdr) @ 2.1bar
Old setup: 280kws (vdr) @ 24psi [email protected]
Previously owned the FRONTN Cordia.
|MAP shortblock 2.4LR 10.5:1CR|MAP EF3|GSC S2|Ohlins coilovers|Cusco|Endless|Meek|Turbosmart|Spoolin Up|Bosch 2000|Walbro 400|Zeitronix|GM|Kumho|Stock ported intake and exhaust manifolds|
366kws (vdr) @ 2.1bar
Old setup: 280kws (vdr) @ 24psi [email protected]
Previously owned the FRONTN Cordia.
#10
Posted 05 August 2011 - 04:22 PM
richie k
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plugs only went in last week but il check the leads in awhile
trying to get my hands on boost gauge/controller so might have a better idea then. found a nice apexi avcr going cheap on ebay so just waiting and hoping to outbid.anybody know if the hks evc are any good?
thanks agin for advise lads
trying to get my hands on boost gauge/controller so might have a better idea then. found a nice apexi avcr going cheap on ebay so just waiting and hoping to outbid.anybody know if the hks evc are any good?
thanks agin for advise lads
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