Overboost??

[antgtir]

When the engine is cold (i think) i seem to experience a small amount of overboost, the car is not exceeding the capabilitites of the fuel pump (standard) however there is a noticeable difference in power, acceleration and gauged (standard gauge) boost levels. Once warm the problem seems to be gone.

What could be the root cause of this annomoly?? I have checked all the intercooler (standard) pipes and the small vacuum pipes that attach themselves on to the intercooler and they are all attached correctly and are tight. With this in mind does that point the finger towards a sticky actuator??

If so are there any methods of removing this problem, maintenence and or replacement??

If not, what else is there to check??

Your help in this annoying little fecker will be much appreciated.

Many thanks in advance,

Ant. :?

 

[Gray]

Mine does the same, im not too worried about it.

 

[GTiR_Mic]

No sure what the porblem is but I wouldn't be boosting when the egine is cold

Mic

 

[GTiR Jon]

Are you sure u're not just losing power when the engine is hot? As mine used to feel like it was over boosting until the engine was at normal running temp, then the boost dropped. Turned out to be the turbo.

 

[Gray]

I thought the same, the air going in would be cooler so more dense so more boost?

As said, no point in boosting til engine warms up anyway as its not a good idea.

I'll be running 700cc injectors and greddy emanage soon so wont be too worried if it overboosts as the fuel should be there.

 

[antgtir]

Sorry didnt explain quite right. I dont go on boost when its "cold" i meant when the car wasn't hot (just warm enough to be using the turbo).

When just in the warm state, the boost gauge reads above the 0.7bar mark (i.e. past the gauge markings), then when the engine is hot the boost is reduced to what i thought is normal at around 0.65bar.

GTiR Jon: What other symptoms did you have i.e. what turbo symptoms did you have?? I have no smoking or oil loss etc and the turbo seems to spool up ok and smooth. :?

Any more suggestions?? What about the actuator possibility??

Ant.

 

[Mr GTiR]

Could it not be heat soak as the engine is getting warm.

It's only 0.05 of bar so don't worry about it.

 

[Gray]

Aye heat soak, dont worry about it. Mines the same, no smoke, no oil loss, no water loss, no problems. Just the air going in is cooler than when properly warm.

Hence why in cold weather it shifts more!

 

[antgtir]

Could it not be heat soak as the engine is getting warm.

It's only 0.05 of bar so don't worry about it.

Thats all the gauge can show as it goes past the last markings so it could be alot more not just 0.05bar.

Heat soak, doesn't feel like it though, i will keep a close eye on it and see if the signs change over time but as with everyone i would rather catch it sooner rather than later if it is a problem that would become progressively worse.

Gray: I thought you had a FMIC now, surely that should rid you of any noticeable heat soak??

Ant.

 

[Gray]

I do have a FMIC. I thought it might be cos when the engines warmer the intake temp would be warmer.

Hiteq are remapping it soon so i'll just leave it up to them it only started happening really since i fitted the FMIC.

 

[paz]

If it was all the time, although not the most technical of people, I'd guess its got something to do with your basic breathing mods - filter and exhaust. The reason I say this is because a mate of mine who has a supra immediately used to get higher levels of boost when he fitted an uprated exhaust.

If its only when not fully warm, I'd say similar to gray - the intake air is denser hence more power!

Paz