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Old 06-03-2020, 09:48 AM   #26
Vadru
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Now I got the new MAF and for sure the old one was broken. The old one would increase alot slower on lower rpm. But now I’m running too rich instead... on 5th gear I get 10 AFR already at 2500 rpm and the gauge I’m using only show as low as 10, so god knows how rich I’m running. Faulty MAF again or any other ideas?
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Old 06-06-2020, 07:22 AM   #27
Vadru
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Noone got any ideas?
I really need my car to work because this is my only car running atm.
And with the old maf it get too little fuel and new one too much, could it really be the maf again or do I have some air leak that I can’t find or some other issue?
As of now I really don’t like to drive the car because I’m scared I will break something when it gets so much fuel.
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Old 06-06-2020, 02:54 PM   #28
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Are you running standard fuel pressure again? Have you checked that the fuel pressure regulator is working correctly and that the vacuum line is dry (what's the pressure at the rail at idle and at 2500rpm)? I'd also check carefully for air leaks all the way from the MAF to the head.
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Old 06-06-2020, 08:08 PM   #29
Vadru
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Quote:
Originally Posted by bobxyz View Post
Are you running standard fuel pressure again? Have you checked that the fuel pressure regulator is working correctly and that the vacuum line is dry (what's the pressure at the rail at idle and at 2500rpm)? I'd also check carefully for air leaks all the way from the MAF to the head.
Yes the pressure is set to standard; and I have checked for air leaks. I also find it unlikly if it is air leak since on max boost I have good afr, it’s only when boost start to come it gets too much.. if I had air leak it should run even richer on max boost right?

The vacuum hose is dry and if I rev the engine it increase the fuelpressure for a little bit and then go back to normal, like it should.

The car went from using 9 liter per 100 km to 13 l. So right now I’m driving with lower fuel pressure, but even now it show 10 afr sometimes. It’s so weird.

Last edited by Vadru; 06-06-2020 at 08:18 PM..
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Old 06-06-2020, 08:32 PM   #30
Vadru
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I made a video showing the AFR.
The 11.02 mark was hit aroune 2500 rpm and then it started to run leaner, even thought I did not stop to accelerate and then @ around 4-5000 it start to run too lean because right now I have too low fuel pressure, but how come the car get this much fuel around 2500 rpm even with lower fuel pressure??

Also when I start the car it has 10 afr until car is warm, with old maf I had 12-13, which I think is more normal. I’m thinking if I have an air leak it should run too lean @ idle because of vacuum, or am I thinking wrong?

https://streamable.com/jpdkfx

Last edited by Vadru; 06-06-2020 at 08:37 PM..
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Old 06-07-2020, 09:44 AM   #31
Vadru
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I did some readings today. At idle it’s pending between 2 and 2.1 bar, when I rev the engine it increase to 2.5 and according to my boost gauge I have 0.5 vacuum, so it seems ok.
If I hold the rev up it goes down to 1.9 due to increased vacuum, so seems to follow vacuum/boost pretty good.

However this means I’m now running with 2.5 fuelpressure instead of the standard 3 and it’s still running rich when boost comes and ofcourse running lean at max boost. Can this really be an air leak?

Anyone got any more ideas?

Last edited by Vadru; 06-07-2020 at 10:46 AM..
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Old 06-08-2020, 09:50 AM   #32
Vadru
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Today I messured the maf voltage and it was only 4.7 @ 6000 rpm, so no wonder I’m running rich. So I installed the old maf and it also only show 4.7, I remember last time I checker it read 5. What could have happened?

Also I noticed at idle the new one show 2.5 and old 2.3, so that’s why I’m running super rich cold start with new maf.
Could this be wiring issue, even thought I get the 1.4 volt like I should when I turn the key?
Or is both my mafs faulty?
Or am I just really bad at finding air leaks, got any good tips how to check?
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