HP equals ambient temp ??? Please Help

[Fos]

When driving at night, the engine pulls fine. Accelerates great at wot and everything's like it's suposed to be.. But with a hot day, It doesn't go at all... going wot results in allmost no acceleration, driving me crazy. What could it be? some kinde of a temp sensor problem?

 

[Fos]

Only 2 probable causes that me and my friend could come up are:

1) dirty IC
2) broken IAT sensor inside the MAF

If anybody has any other suggestions, please post. I will try to look them all over, once I get to my garage tomorrow.

 

[Staytuned]

All I can say is that with high coolant temps and high intake temps the ECU will pull timing. And also cool air = more HP cause it is more dense.

 

[Fos]

yeap I know that. I allso have timing problems, probably due to the hot air. I'm ripping apart the nose of my car today and give the cooler a good wash with some ordinary 95 octane...

I will post the results....

 

[DSM90AWD]

Make sure that your MAS is plugged in correctly. If it wasnt', your car woudl go into "safe" mode which limits timing advance and makes you run very rich. This would also explain why it runs better at night as cooler-denser air would raise AFR slightly under this mode (vs. hot daytime air temps).

FYI, the above and any sensor within the MAS (and others) will throw a CEL to tell you for sure.

Once you done all your checks, reset the ECU by removing the (-) battery cable for 20secs or so which will clear any stored codes

 

[Fos]

Make sure that your MAS is plugged in correctly. If it wasnt', your car woudl go into "safe" mode which limits timing advance and makes you run very rich. This would also explain why it runs better at night as cooler-denser air would raise AFR slightly under this mode (vs. hot daytime air temps).

FYI, the above and any sensor within the MAS (and others) will throw a CEL to tell you for sure.

Once you done all your checks, reset the ECU by removing the (-) battery cable for 20secs or so which will clear any stored codes

If I unplug my MAF, the car runs very crappy... I can tell, it's not in the safe mode.
I cleaned my cooler yesterday, still getting some odd behaviour. Havent had the chance to test it in cold and in warm yet.

Could the removal of the plastic holding the honeycombs inside the MAF end up running a bit lean? As I understand, there is a section in the bottom of the MAF, where unmeterd air enters, based on road race engineering.

Another thing, If I'm driving 95 octane, what should my a/f readings be on WOT ? 0.92 V?
and on 98 octane about 0.88 ?

 

[keymaster]

It's impossible to get an accurate AFR reading from the stock narrowband, don't even bother trying to tune based on the numbers it gives you. Do you have a logger? If you do, and you should, do a 3rd gear pull to redline and post it up.

 

[4BangR-x]

Ordinary 95 octaneWTF

DSM90AWD

If he didnt have the mass correctly plugged in, wouldnt it just die?

 

[MrBoxx]

Ordinary 95 octane

In Europe, they measure octane just by the Reseach Octane Number (RON) whereas the US uses the R+M/2 formula to measure octane. Our 87 octane is Europe's 91, etc. It's usually about 4 or 5 points above the US's measurement.

 

[DSM90AWD]

If he didnt have the mass correctly plugged in, wouldnt it just die?

Nope. ECU has a failsafe mode in the eventuality your MAS were to crap out. Allows you to make it back home but will run really rich, limit timing and throw a CEL

 

[Fos]

jeap, the only gas that we have here for driving is 95 octane and the 98 octane.... If anybody knows how to compare them with US gas exactly, let me know. Then I would know what should my af ratio be.

And Yes I have a logger. Will do a 3gear pull day after tomorrow and then post it...

ouhh... what should i log?

rpm, TP, air flow, Timing, O2, stft and ltft? will that do?

 

[keymaster]

Log RPM, timing, and airflow.

 

[Fos]

Happy news, It was the dirty IC messing with me. Didn't notice before the weathere here in estonia went 30+ degrees.

Having still some setbacks with warm weather, but I guess it's from a lack of cold air intake. My cone filter is breathing straight from the engine room. Not good at all. Will get it fixed asap.

Thanks guys for all the replys...