Help: Evo IX running lean, stock MAF/Injectors - Page 2

evonut270 · Oct 28, 2009, 03:29 PM

why is the car only running 10psi boost? stock is around 1.2 bar(19 psi).have you tried disabling lean spool and see what AFRs you get then?

crcain · Oct 28, 2009, 06:29 PM

Quote:

Originally Posted by evonut270

why is the car only running 10psi boost? stock is around 1.2 bar(19 psi).have you tried disabling lean spool and see what AFRs you get then?

It's running 10 psi because the fuelling is not correct. Once the issue is sorted we'll turn the boost up.

I will try disabling lean spool, however, I don't think lean spool can account for the fuel map I posted yielding 11's up to 6k rpm. Nevertheless I'll try disabling lean spool and see what happens. Appreciate the help!

4kinboost · Oct 28, 2009, 08:00 PM

Here's a quick few suggestions...

1- Switch the Maf with another and see if it resolves your problem.

2- Check the maf pipe for any leaks ( sucking unmetered air)

3- make sure the fpr hose is not t'd to anything else ( like a leaky line to a boost guage)

Since 2 different maps had the same issues, i would suggest this is more of a mechanical issue.

Good luck Ccrain!

crcain · Oct 29, 2009, 08:43 AM

Quote:

Originally Posted by 4kinboost

Here's a quick few suggestions...

1- Switch the Maf with another and see if it resolves your problem.

2- Check the maf pipe for any leaks ( sucking unmetered air)

3- make sure the fpr hose is not t'd to anything else ( like a leaky line to a boost guage)

Since 2 different maps had the same issues, i would suggest this is more of a mechanical issue.

Good luck Ccrain!

Those are good suggestions.. I've got a few friends with IX's so #1 won't be a problem. #2 I hadn't thought off and would lead to lean conditions so I'll check that out too. #3 I did check, and it was not tee'd. But I'm thinking I'll replace the vacuum hose just in case it's split underneath it's heat shielding.

Thanks for the wishes of luck!

SyZyGy1394 · Oct 29, 2009, 09:09 AM

Have you tried messing with lean spool and turning it off and seeing if it does anything? I know it won't do much tho, just spitting out random crap that comes to mind...

Edit: whoops someone already said that!

crcain · Oct 30, 2009, 07:05 AM

Got a call last nite saying he tried swapping the regulator and still no luck.

Still have to swap the MAF... also when I see him next I'll change the vacuum line and vacuum source of the regulator to remove that as a possibility.

Desperate times...

jid2 · Oct 30, 2009, 10:59 AM

You need to verify it's not the wideband. I thought I was having the same issue. I spent 3 weeks and $1000 buying new fuel system related parts and it was my wideband. It read correctly at idle and part throttle, but as soon as you would hit WOT it would shoot to 14. It took me 2.5 weeks to get a new sensor on the wideband and that was the problem the whole time.

But now I have a double pumper, new regulator and brand new pumps!

nj1266 · Oct 31, 2009, 05:30 PM

It is the MAF. I had a similar problem on a used Evo IX that I tuned. Could not get the car to richen up. The fuel map looked EXACTLY the same as the one you posted. maxed rich at 7.4:1 target AFR.

I had a spare MAF. We swapped it and everything was fixed. One way to tell if the MAF is faulty is to check the load numbers. If the load numbers are too low for the modifications on the car, then it should be the MAF.

nj1266 · Oct 31, 2009, 05:32 PM

Quote:

Originally Posted by jid2

You need to verify it's not the wideband. I thought I was having the same issue. I spent 3 weeks and $1000 buying new fuel system related parts and it was my wideband. It read correctly at idle and part throttle, but as soon as you would hit WOT it would shoot to 14. It took me 2.5 weeks to get a new sensor on the wideband and that was the problem the whole time.

But now I have a double pumper, new regulator and brand new pumps!

Shouldn't a wideband give an Error reading when the sensor goes bad? Mine does that. I thought all of them did

**MR Turco** · Nov 6, 2009, 06:51 AM

ccrain, ever figure this out? I am working with the local tomorrow to see what fixes his. I might try the maf first.

crcain · Nov 6, 2009, 09:03 AM

I met up with him the other night. He had tried everything, regulator, fuel pump, fpr vacuum source, boost leak test, maf swap, etc...

After trying everything, I said screw it and turned off lean spool and started tuning. With lean spool disabled it seemed like I didn't need to add nearly as much fuel as before to get the afr's in the ballpark. We didn't have a lot of time so I needed to finish the tune later, but the fueling was almost spot on and I think I was at a 10.5'ish value in the fuel map which yielded an 11.5 afr when we left off. So not bad.

In the end I'm feeling pretty dumb. I started with a hypothesis that stock injectors, stock maf, stock ecu and a few bolt ons would amost always yield a fuel curve that was in the ballpark. The truth is I didn't have a lot of experience with this as most of the evos I had tuned were on bigger injectors which changes everything obviously. It was this assumption that led me to not start tuning until we figured out the problem. But maybe there never was one. I still don't see how you can bolt on an exhaust, intake and some I/C pipes and get an Evo running in the 14's at 6k rpm.

I only have one pause, which is that I had the owner check the voltage at the fuel pump housing while driving. He said on boost it was like 12's, 12 high. So I do wonder if the pump was hard wired and seeing 13's, low 14's voltage that would make any difference. I doubt it.

Still sort of a mystery.. I'm gonna have him get a relay, fuse, etc and hard wire his pump and see if it makes a difference. Not sure if he will ever get around to it though.

crcain · Nov 6, 2009, 09:08 AM

Just to add one other thing, I was thinking of the stock injector Evo's I had tuned on stock ECU/MAF... one was a Greddy T67 Evo 5... another a FP Red Evo X, and another a IX with no parts at all. All of these Evo's had afr's in the ballpark with the stock fuel map.

So it was those experiences, plus how I thought logically about how the MAF meters air that made me think that in almost any parts combination, the stock ECU/MAF/injector car would have afrs in the ballpark regardless of whether lean spool was enabled or not.

Might be a wrong assumption though. Hard to say without more experience.

jcsbanks · Nov 6, 2009, 04:57 PM

Have you tried another MAF sensor? Is there a cone filter on it?

crcain · Nov 7, 2009, 08:45 AM

Quote:

Originally Posted by jcsbanks

Have you tried another MAF sensor? Is there a cone filter on it?

JC thank's for listening to this diatribe

Yes we did change MAF, regulator, fuel pump, vacuum line and vacuum source to regulator.

Yes he is running an HKS mushroom filter with an HKS aluminum intake pipe.

4kinboost · Nov 7, 2009, 10:48 AM

Quote:

Originally Posted by crcain

JC thank's for listening to this diatribe

Yes we did change MAF, regulator, fuel pump, vacuum line and vacuum source to regulator.

Yes he is running an HKS mushroom filter with an HKS aluminum intake pipe.

If you are looking to have your fuel map in more of a numerical synergy with your afr's using this intake kit, you will need to 'massage' your maf scaling just a tad.

Glad you sorted out the issues!