jerky

[ev0_238]

Right all u evo experts out there i have a problem yep again so here we go when i pull off the car is very lumpy and jerky on low revs to a point where it will stall but once the boosy kicks in its fine but when its just cruising along say 4th gear its like its l;oosing power so have to downshift what you all think also the car is underperforming and stuttering in low revs maybe possible ecu or lamba sensor what you all think

 

[evo arm's m7960]

hi buddy
what evo is it ?is it standard and how long has it been playing up ?

what have you looked at so far ??

whats it like on idle ?any strange noises ?


.

 

[ev0_238]

hey m8 the stuttering was there but was not as bad as when it came out the garage

this is what the new mechanic i took it to did

set up throttle position sensor to 170 volts
checked compression of engine 170 160 165 160
checked cam timing tried airflow meter,cam sensor coil packs and leads from another working evo and the fault is still occuring
lamba sensor reading is high possible lamba

noise the engine seems louder that what it was

on low revs it really stuttery and its a evo 5 stock now as some coont stole my boost controller so could be that the ecu needs reflashed

so on the look out for a evo 5 or 6 ecu

 

[B6lee]

Sounds as though you have covered all possible issues. Will have a think about it an see if anyone else can come up with any possible ideas

 

[RsvRob]

running lower boost than it was mapped for shouldn't cause your problem so no need to look for another ecu

has it had diagnostics plugged in?
or
flashed the fault codes out using pin 1+4 on obd port?

also get afr's checked
or
when you boot it do you get a puff of black smoke from exhaust indicating over fueling ... ie ucked lambda

 

[ev0_238]

not yet will take it to a place where i can get it diagnosed properly as its got me confused hahahah

 

[B6lee]

Take it to a trusted specialist mate. They are cheaper than Mitsi and they know alot more

Ma developments in Berkshire or engine tuner in Plymouth

 

[foxy lady x]

best get it checked out by someone who knows whats what, i'd say at a guess lamba sensor, have you had any pipes changed on ur turbo ?

 

[HermaN]

Boost leak or lambda issue going by what you have already tested. Lambda is piss easy to test, get your multi meter out, set it to read voltage and check the voltage across the lambda, it should be constantly jumping between 0.1 - 0.9v if it's working properly, outwidth that range it's goosed.

Boost leak will cause unmetered air to enter on cruise & idle and if big enough will cause stalling, but on boost it will cause metered air to be lost, so the car runs rich.

 

[ev0_238]

cheers herman foxy mechanic says in the report that the lamba reading was high so that could be the problem as he went over the turbo would the lamba sensor cause the vehicle to stutter and not tick over right seems liek when it starts if u dont give it a wee rev it will just cut out

 

[RsvRob]

If the lamda was ucked and giving false readings then the ecu would interpret it wrong and either add or decrease fuel as needed causing it to stall.

Peviously mapped a car running very lean and was stuttery/jumpy before turbo kicked in. Even running a fuel map richer than the safe low octane didn't solve it. Told him to get a new lambda. Fitted it and checked fueling again and found it was now spot on. No jerkyness and afr's perfect

 

[HermaN]

Check the lambda sensor with a multi-meter instead of asking on here if a faulty lamda would cause X/Y/Z. Takes 2 mins to do and will tell you 100% if the lambda is the cause. If it's working the voltage will constantly fluctuate between 0.1 - 0.9v, if it's goosed it wont, simple.

TBH, your mechanic should have done this, but sounds like they havn't bothered, because if they had they would have told you if it was goosed.

 

[ev0_238]

still the same

ok guys fitted lambda sensor and its still the same on idle revs just drop till the engine cuts out and on take off its really jerky and stuttery proper pulling me hair out now pleaseeeee help wayne

 

[Steve220]

I'd be changing spark plugs by now

 

[ev0_238]

spark plugs checked the garage checked them all