Running lean in Boost, Help
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
Need the Experts, Running lean in Boost, Help
Ok, car is a 2002 procharged Fast 102 headers A4. Had my issues resolved before which was the Map sensor, Now I have a new map sensor(3 Bar), new o2's and a new MAF, The car runs alot better, just going into boost a/f guage read the dump at 10.5 then goes to 11.5, 12.8, 13.2, as the rpms increase.
When I worked on the car a few days ago, I removed the headers and Fast 102 intake , but torqued it properly,
Any suggestions, Ideas Thanks.
I believe it could be the MAP sensor location fitment, not properly sealing, I am getting the RTV on it now and letting it dry over night? Will check tomorrow
When I worked on the car a few days ago, I removed the headers and Fast 102 intake , but torqued it properly,
Any suggestions, Ideas Thanks.
I believe it could be the MAP sensor location fitment, not properly sealing, I am getting the RTV on it now and letting it dry over night? Will check tomorrow
Last edited by corvet786c; Sep 17, 2021 at 03:33 PM.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
Also I double checked the header bolts this afternoon and the passenger side bolt was torqued, but I went a quarter turn and now its stripped. So not sure if that bolt was the issue, running a lean condition
I sealed the MAP sensor on the fast 102 hopefully no leaks.
I did a few pulls today on an open road and it seemed that the 11.5 AFR was holding on my guage to about 4500 rpms, but then started going lean to 13.2 under boost. Unless its giving me a false reading
But I got to get that header bolt tapped, before I do another WOT pull. I hate pulling the header. Yikes.
Last edited by corvet786c; Sep 5, 2021 at 06:41 PM.
Melting Slicks
Joined: Mar 2006
Posts: 2,754
Likes: 379
From: South Florida FL
there's some backstory I don't get. what problem were you chasing before you started changing sensors, is the lean issue a new problem? if not, at what point in you changing parts, did the issue appear. if you changed stuff than can affect the tune and airflow. it being lean now isn't farfetched.
if you don't have a voltmeter, at minimum you can looks at the battery voltage on the cluster. also having good fuel pressure at idle, doesn't mean it'll be good at WOT. you basically need more data to diagnose this properly
if you don't have a voltmeter, at minimum you can looks at the battery voltage on the cluster. also having good fuel pressure at idle, doesn't mean it'll be good at WOT. you basically need more data to diagnose this properly
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
there's some backstory I don't get. what problem were you chasing before you started changing sensors, is the lean issue a new problem? if not, at what point in you changing parts, did the issue appear. if you changed stuff than can affect the tune and airflow. it being lean now isn't farfetched.
if you don't have a voltmeter, at minimum you can looks at the battery voltage on the cluster. also having good fuel pressure at idle, doesn't mean it'll be good at WOT. you basically need more data to diagnose this properly
if you don't have a voltmeter, at minimum you can looks at the battery voltage on the cluster. also having good fuel pressure at idle, doesn't mean it'll be good at WOT. you basically need more data to diagnose this properly
So when I hit it the AFR Guage goes to 10.0 then rises to about 13.0 at about 4800 rpms and I just shut it down, Dont know what else to do anymore.
My question is just changing MAP, MAF or O2 sensors affect the tune if they were the same part number? I didnt think it would?
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Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
ok here is the original map sensor with the tune, IS this a 1 or 3 bar map? This was actually epoxied to the intake no leaks at all, 11.5 all the way up, Not so much now.
Last edited by corvet786c; Sep 6, 2021 at 05:21 PM.
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
That appears to be a stock 1 bar map sensor.
You cannot just randomly change it for any other sensor unless you are also going to re-program the ecu for whatever sensor you are fitting.
You cannot just randomly change it for any other sensor unless you are also going to re-program the ecu for whatever sensor you are fitting.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
This is what is on my car now, not sure what brand it is or if it is a 3 bar?
Last edited by corvet786c; Sep 6, 2021 at 06:04 PM.
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
no idea what it is, google the numbers to see if anything comes up.
But as the map sensor can be a critical sensor, where possible I would always use genuine OEM parts, not some cheap unknown chinese ***** copy.
But as the map sensor can be a critical sensor, where possible I would always use genuine OEM parts, not some cheap unknown chinese ***** copy.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
Le Mans Master
Joined: Jul 2010
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Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
If you unplug the MAF, then it may revert to using MAP more so.
Of course any fallbacks assume whoever has tuned it, has done so to allow that to happen.
If he has the wrong sensors the car/ecu is tuned for....he's screwed either way
Last edited by stevieturbo; Sep 7, 2021 at 02:00 PM.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
The photo I posted is a 1 bar pf the original map, then thats what I have now.
Last edited by corvet786c; Sep 7, 2021 at 02:18 PM.
Racer
Joined: Mar 2019
Posts: 385
Likes: 102
From: Virginia
well like I said, bought an ac delco this morning, the idle seems smoother, did a couple of pulls under boost and AFR drops to 10 then 11 seems to stabalize to around 11.6. I am happy plus he gave me a refund for the MAP sensor he put in.
The photo I posted is a 1 bar pf the original map, then thats what I have now.
The photo I posted is a 1 bar pf the original map, then thats what I have now.