overboost but no fuel cut?!

[adz_sportif_turbo]

i put me toe down on the way home earlia in 3rd, and the engine management light came on!! 1st thing i thought...'greeat whats wrong now?!' looked at my ebc and it peaked at 13.5!! is a cold night, lovely dense air. but it didnt hit fuel cut?? turned the engine off and on, eml went off. shouldnt of i hit fuel cut??

[Glanza AuA]

im also hitting fuel cut sometimes,but i know for sure its becuase of the boost creep i have learned

basicly you ECU has a safty feature that shuts down the fuel before somthing bad happens,and thats why your having the engine management light on

why don't your try now the diagnose test to see what did cause the engine management light to come on in the first place?

[adz_sportif_turbo]

im also hitting fuel cut sometimes,but i know for sure its becuase of the boost creep i have learned

basicly you ECU has a safty feature that shuts down the fuel before somthing bad happens,and thats why your having the engine management light on

why don't your try now the diagnose test to see what did cause the engine management light to come on in the first place?

thanks for the reply mate. yea i know what fuel cut is, and i know its quite violent when you reach it. but my car didnt hit fuel cut, it just overboosted. jw if anyone else has experienced this??

basically is it possible to overboost without hitting fuelcut?? i have no fcd

[Glanza AuA]

im also curious on that one

[Jozinobi]

Check your boost pipes going from your ebc solenoid to either the actuator or the turbo and make sure they are all tight and secure.

You may also have a different vacuum leak somewhere that may only occur on full foot plant as 3rd gear gives the strongest push.

Mine recently popped off the turbo and caused an overboost situation to 1.4/1.5 bar on CT9.

It will basically boost freely and not hold to any given pressure = overboost.

I have an emanage (mapped to 1bar) and in the case of overboost it will kill all timing and run very rich so it won't lean out at that moment.

This safeguard basically saved my engine but I wouldnt like it to happen again. If this happens constantly you could melt a piston, blow the turbo or other internal damage worst case scenario. Thankfully still driving fine on and off boost and pulls the same = lucky.

Not a very nice sensation thats for sure, be careful and if it happens again I'd drive off boost and stop and check it out just in case.

Joz

[adz_sportif_turbo]

Check your boost pipes going from your ebc solenoid to either the actuator or the turbo and make sure they are all tight and secure.

You may also have a different vacuum leak somewhere that may only occur on full foot plant as 3rd gear gives the strongest push.

Mine recently popped off the turbo and caused an overboost situation to 1.4/1.5 bar on CT9.

It will basically boost freely and not hold to any given pressure = overboost.

I have an emanage (mapped to 1bar) and in the case of overboost it will kill all timing and run very rich so it won't lean out at that moment.

This safeguard basically saved my engine but I wouldnt like it to happen again. If this happens constantly you could melt a piston, blow the turbo or other internal damage worst case scenario. Thankfully still driving fine on and off boost and pulls the same = lucky.

Not a very nice sensation thats for sure, be careful and if it happens again I'd drive off boost and stop and check it out just in case.

Joz

i have a greddy profec b 2, but the solenoid isnt rigged up at mo im just using it as a accurate boost gauge until i get a hks actuator. i read on tgtt that the eml comes on just before fuel cut, is this true?? yea as soon as the light came on i let off straight away, didnt wana do damage lol.

surely though at 13.5 psi i should have hit fuel cut?? do they all differ??

[Jozinobi]

I see, so it can't be your ebc solenoid then.

The main case of overboost is a sudden vacuum leak so check any other pipes etc.

There is a type of fuel cut where the eml doesnt turn on, first stage of it if you like, but you get the same sensation.

When the eml comes on as well you could say it is the most severe form of it, not to worry you or anything as it does happen.

This is probably if the boost spike was more than usual.

Fuelcut is annoying especially when you are running a peak of 0.8 bar, it WILL hit as you have found out on cooler nights.

Best way is to get an emanage ultimate on there, it will bypass fuelcut/speedcut, allow more boost and will map your car's afr optimally = decent tune. You can also set your own rev limit and for kicks a basic launch control. A full kit can be picked up for less than the price of a plug and play ecu.

Joz

[adz_sportif_turbo]

I see, so it can't be your ebc solenoid then.

The main case of overboost is a sudden vacuum leak so check any other pipes etc.

There is a type of fuel cut where the eml doesnt turn on, first stage of it if you like, but you get the same sensation.

When the eml comes on as well you could say it is the most severe form of it, not to worry you or anything as it does happen.

This is probably if the boost spike was more than usual.

Fuelcut is annoying especially when you are running a peak of 0.8 bar, it WILL hit as you have found out on cooler nights.

Best way is to get an emanage ultimate on there, it will bypass fuelcut/speedcut, allow more boost and will map your car's afr optimally = decent tune. You can also set your own rev limit and for kicks a basic launch control. A full kit can be picked up for less than the price of a plug and play ecu.

Joz

ahh right interesting. what i found though was the light came on, but i didnt feel fuelcut. unless i let off so quickly that it didnt have chance to cut. i know i dont have a vac leak, im running a short inlet route and meshed pipe lol, caused it to spike. thanks for your help mate

[Jozinobi]

No worries mate

It is obviously your extremely short intake route that is causing the trouble as they so often do.

You won't know yourself once you get it sorted, nothing to worry about then.

Joz

[Glanza_cl]

sounds to me like you just got close but let of just in time to not hit the ECU's fuel cut off.

I used to be able to boost on a cold night right upto fuel cut level, i could see my engine management light come on but i had set up my boost controller well enough to drop boost pressure so not to hit fuel cut and bring it down to a safe level again.

As Joz said mate, will just be a combination of cold night and short intake creating an unstable rapid build of pressure most likely leading to a spike in boost. it might also be good to relocate your ebc's vac source as if you had peaked at around 0.9bar plus the ecu would have cut in. if your running it off multiply vac sources or perhaps a long vac line it wont be as accurate. straight off the map sensor vac will be the most accurate.

[adz_sportif_turbo]

sounds to me like you just got close but let of just in time to not hit the ECU's fuel cut off.

I used to be able to boost on a cold night right upto fuel cut level, i could see my engine management light come on but i had set up my boost controller well enough to drop boost pressure so not to hit fuel cut and bring it down to a safe level again.

As Joz said mate, will just be a combination of cold night and short intake creating an unstable rapid build of pressure most likely leading to a spike in boost. it might also be good to relocate your ebc's vac source as if you had peaked at around 0.9bar plus the ecu would have cut in. if your running it off multiply vac sources or perhaps a long vac line it wont be as accurate. straight off the map sensor vac will be the most accurate.

yes i think i let off in time. my ebc vac source is on its own, i dont run power steering or aircon so a lot of the nipples on the inlet manifold arnt being used. i will just take it easy until i can afford an actuator, then i can set up the ebc with it and hopefully will be perfect.

thanks for the help nice to know i can just consult people on here who have been there and done it lol