Crackle pops during wot

[D-VO]

@steve99 - So today I was able to reflash for the factory MAP sensor and drive the car again: This time the car misfired at 6000RPM again, but I got a p0108 (Input Voltage to high at MAP) at the same time. Going for a new 4 bar MAP sensor, but I don't understand how a MAP sensor can go bad after an intercooler pipe blew off.

[Tcoat]

Originally Posted by D-VO

@steve99 - So today I was able to reflash for the factory MAP sensor and drive the car again: This time the car misfired at 6000RPM again, but I got a p0108 (Input Voltage to high at MAP) at the same time. Going for a new 4 bar MAP sensor, but I don't understand how a MAP sensor can go bad after an intercooler pipe blew off.

Did you suck some steam up into the intake?
I blew a heater line on one of my cars and the steam it sucked it messed with all my air sensors since when the water evaporated it left a film of the additives all over them.

[D-VO]

Originally Posted by Tcoat

Did you suck some steam up into the intake?
I blew a heater line on one of my cars and the steam it sucked it messed with all my air sensors since when the water evaporated it left a film of the additives all over them.

Well it did suck in a boat load of hot air since the I/C pipe that decoupled was the one before the MAF sensor.

[jflogerzi]

Originally Posted by D-VO

Well it did suck in a boat load of hot air since the I/C pipe that decoupled was the one before the MAF sensor.

MAF cleaner?

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[D-VO]

Originally Posted by jflogerzi

MAF cleaner?

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I had a second MAF sensor that I tried. No change.

[Tcoat]

Originally Posted by D-VO

I had a second MAF sensor that I tried. No change.

Connector look OK?

[D-VO]

Originally Posted by Tcoat

Connector look OK?

Yep. Everything looks good. I'm trying to find where that vacuum line that comes off the throttle body goes. I see it goes into the sensor under the intake manifold then goes up between the fuel line then goes back down underneath the car. I'm thinking there may be a vacuum line that popped off in the back of the car that I can't see or hear. I've been looking for a vacuum diagram online with no luck.

[Tcoat]

Originally Posted by D-VO

Yep. Everything looks good. I'm trying to find where that vacuum line that comes off the throttle body goes. I see it goes into the sensor under the intake manifold then goes up between the fuel line then goes back down underneath the car. I'm thinking there may be a vacuum line that popped off in the back of the car that I can't see or hear.

Here are the service manuals. There is a vacuum line diagram in there someplace.


https://demos.starbase7.net/t3Portal/

[jflogerzi]

Originally Posted by D-VO

Yep. Everything looks good. I'm trying to find where that vacuum line that comes off the throttle body goes. I see it goes into the sensor under the intake manifold then goes up between the fuel line then goes back down underneath the car. I'm thinking there may be a vacuum line that popped off in the back of the car that I can't see or hear.

If you did not clamp it down when switching to FI that could be an issue for sure.

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[D-VO]

So here is the list of things I've looked at or tried swapping so far:

Everything is clamped
Tried a new MAF
Tried a new MAP
Cleaned Throttle body twice
No vacuum leaks
Spark plugs are clean no fouling
No SES light or codes
Followed that vacuum line from the sensor underneath the intake manifold to the back; Still connected.
Car still pulls hard until the misfire then the RPM's will not raise any higher

A few weeks ago the misfiring was at around 6000 RPM, now the misfire starts down at 4000RPM. I only checked the resistance of the coils which gave me consistent readings but I'm not sure if there's anything else I can do. Has ANYONE else experienced this?

[jflogerzi]

Originally Posted by D-VO

So here is the list of things I've looked at or tried swapping so far:

Everything is clamped
Tried a new MAF
Tried a new MAP
Cleaned Throttle body twice
No vacuum leaks
Spark plugs are clean no fouling
No SES light or codes
Followed that vacuum line from the sensor underneath the intake manifold to the back; Still connected.
Car still pulls hard until the misfire then the RPM's will not raise any higher

A few weeks ago the misfiring was at around 6000 RPM, now the misfire starts down at 4000RPM. I only checked the resistance of the coils which gave me consistent readings but I'm not sure if there's anything else I can do. Has ANYONE else experienced this?

Can you tell what cylinder the miss fire is coming from? Replace that plug and coil pack and see if that fixes it. Use ecutek to log

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[D-VO]

I wish I knew someone with ECUTek to log for me. I'm using open source (ecuflash) with tactrix and SD card for logging.

[D-VO]

*ISSUE SOLVED!*

Hey guys. For whoever is still following this issue: I ended up changing ALL 4 coils. So just to catch up, I had a spare coil and decided to change the coil with the highest number of resistance which was a .91. The other 3 were at .86(<--intentional?). Anyway, the car started misfiring down to 4000 RPM with colder IAT's of 68-75 degrees but was breaking up at 6000 RPM when the IAT's were 90 and up(This was the only log data I had). Not sure if that meant anything. Once I changed the coil that was reading a .91 it made a hell of a difference! However, it was still lagging around 6000 RPM. At this point with no CEL's AT ALL, I decided to change all 4 coils. Good to go!

I'm guessing this means the OBDII system is trash at detecting faults with the coils? Thanks for the replies guys!