Not able to see boost from ecu

I just did a log with enthusiast and my boost will not plot at all in the rom raider. Also when I try reading boost from my AP it never shows the correct value always hovering around zero. My car is making boost for sure but I can't pull it from my ecu. Could I have blown a fuse? Anyone run into this issue before?

I gots no booooost...!! o noes!!11!!

 

 

sensor may be broken

or you're using the wrong parameter in romraider

Log relative manifold pressure (corrected)

 

EDIT: if the AP is not reading it either, I would guess it is the sensor..but I would think that would trigger a CEL?

Log relative manifold pressure (corrected)

 

EDIT: if the AP is not reading it either, I would guess it is the sensor..but I would think that would trigger a CEL?

 

We tried logging that parameter and had no dice either.

I am almost certain that should throw a CEL if the ECU is unable to see boost. Try logging MAP...

I agree with Infamous... if your ECU really couldn't see boost I would expect a CEL or three. There are a few boost parameters, try logging all of them and see which ones (if any...) move in ways that make sense.

Ck the hose on the Map sensor? Mine popped off once.

vacuum line is definitely disconnected from MAP senor. Mine just did this and the ECU only showed atmospheric pressure.

I will check that out when I take a break. Thanks for your help guys.

vacuum line is definitely disconnected from MAP senor. Mine just did this and the ECU only showed atmospheric pressure.

 

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The hose had blown off from the manifold connecting to the MAP sensor, I thought I had zip tied all the hoses but must have missed that connection because its slightly hidden. I had ziptied where it connects to the MAP, just not the other side. Thanks again guys I will try logging my boost when I go to lunch.

Ck the hose on the Map sensor? Mine popped off once.

 

yup mine did this as well. Put a little super glue on the barb & a ziptie on the hose.

Be real careful about that hose popping off. It will cause thecar to run much leaner because it will not properly calculate the load.

For my info, where is the hose to the Map sensor? Where IS the map sensor? Thanks.

Be real careful about that hose popping off. It will cause thecar to run much leaner because it will not properly calculate the load.

How do you figure this if load is primarily calculated at the MAF? (MAF G/S*60/rpms)

That is unless he is running speed density?

How do you figure this if load is primarily calculated at the MAF? (MAF G/S*60/rpms)

 

beat me to it.

At idle the intake is in vacuum, so it pulls in air from outside. That air doesn't get measured by the MAF, so the ECU doesn't add corresponding fuel, so the combustion will be lean. At least, that's my theory behind why my can idled like crap and had 17+ AFRs when I accidentally disconnected a hose from my intake manifold a while back.

 

Under boost it would probably go the other way - air would escape through the leak, but the ECU would add fuel for it anyway (since the MAF saw it) and the AFR would go rich. I didn't test that, though - I fixed the hose before I left my driveway.

At idle the intake is in vacuum, so it pulls in air from outside. That air doesn't get measured by the MAF, so the ECU doesn't add corresponding fuel, so the combustion will be lean.

Even still the ecu has enough compensation to correct a vacuum of that size as it would most certainly be in closed loop.

 

But then he stated load, which is false unless I am missing something.

My AFR at idle was swinging up and down around 17. It was in closed loop, and it was trying to fix the problem, but it was struggling. At high-ish RPM (2k) it did OK, but at straight idle (700ish) it couldn't even keep the motor running.

 

From the MAF (g/s) and RPM (rev/s), the ECU calculates load (g/2rev), and from that it calculates how much fuel to inject, then how long to pulse the injectors. If it can't figure out the load (due to air coming in without going through the MAF), it can't add the right amount of fuel. Where's the problem?

Tommypenguin - did you check the MAP sensor reference line?

Where's the problem?

The problem has nothing to do with fueling to the OP's knowledge. Load and fueling possibilities were introduced by RP. As I stated, MAP has nothing to do with how load is calculated unless running speed density.

The MAP sensor has nothing to do with load calculations, that's true. RP was talking about other implications of the OP's problem - not due to the missing MAP sensor per se, but due to the new leak where the MAP sensor used to be.

The MAP sensor has nothing to do with load calculations, that's true. RP was talking about other implications of the OP's problem - not due to the missing MAP sensor per se, but due to the new leak where the MAP sensor used to be.

Well if that's the case he worded it horribly wrong.

if the MAF goes out of range or gets disconnected the ECU revert to a limp mode and uses MAP to calculate loda

Tommypenguin - did you check the MAP sensor reference line?

 

I zip tied the map reference hose and at all four junctions it can be ziptied. Is there another line I missing?

 

Now that I have been able to log boost I hit 25.2psi on my 21psi map pump gas map. My e85 map is supposed to run 25psi. I need to run another log with rom raider, not going to get into boost until I have the chance to log it and will wait to do that wot log until I have e85 in my tank.

 

Naturally when I noticed I was having an issue last week I had just filled up my tank of gas. Should be another couple of days and I'll be running e85.

25psi that would explain the knock. At altitude that is comparable to 27-28psi at sea level.