MSP Running Real Rich?

[MSPM1cheLe]

success (sort of)! First I deleted my tune. this fixed my cold start up issues. Then I Redid the hardpipes and relocated the MAF after my BOV. This helped alot. Although the car will still reach about 10 AFR when pulled out of gear, it recovers MUCH quicker to 14.7 than before. It takes about 3 seconds to balance out, instead of the 4-7 seconds it used to take. Haven't experienced any fuel bogging stalls yet either.

Just need to see if my "under boost" AFRs are off compared to other MSPs (Hence the thread title change). So if you guys could let me know what your running at under full boost that'd help me out. Usually mine will be at 10.2 after about 3500 rpms in 2nd/3rd.

If ya can, let me know what you guys are at, and also the wideband you are using to get these readings. Thanks

 

[KrayzieFox]

...Just need to see if my "under boost" AFRs are off compared to other MSPs (Hence the thread title change). So if you guys could let me know what your running at under full boost that'd help me out. Usually mine will be at 10.2 after about 3500 rpms in 2nd/3rd.

If ya can, let me know what you guys are at, and also the wideband you are using to get these readings. Thanks

P5-T running 6 psi on MSP turbo setup w/ MAF relocation after HKS BOV that vents to atm.

AFRs are around 11.2 when entering boost at or above 3500 RPM and get as high as 12.5 at WOT. If I enter boost in a higher gear and am below the 3500 RPM range then I'll see AFRs as low as 10.0 until the RPMs rise a bit, then they stick in the 11.2-12.5 range throughout the rest of the powerband.

I use the P5 ECU with the Flyin' Miata O2 sensor voltage clamp, and the BEGi 2025 RRFPR to deliver the fuel. Works flawlessly at stock boost

Under vacuum, AFRs read 14.3-15.7 and the O2 sensor is set to clamp at -2 inHg, which is when I start seeing AFRs in the 11's and 12's so that the extra fuel is delivered right before entering boost.

I hope this helps (2thumbs)


EDIT: I saw that you mentioned that you were interested in other MSP's, but I hope my data still helps. Also, I have the AEM UEGO Wideband.

 

[MSPM1cheLe]

P5-T running 6 psi on MSP turbo setup w/ MAF relocation after HKS BOV that vents to atm.

AFRs are around 11.2 when entering boost at or above 3500 RPM and get as high as 12.5 at WOT. If I enter boost in a higher gear and am below the 3500 RPM range then I'll see AFRs as low as 10.0 until the RPMs rise a bit, then they stick in the 11.2-12.5 range throughout the rest of the powerband.

I use the P5 ECU with the Flyin' Miata O2 sensor voltage clamp, and the BEGi 2025 RRFPR to deliver the fuel. Works flawlessly at stock boost

Under vacuum, AFRs read 14.3-15.7 and the O2 sensor is set to clamp at -2 inHg, which is when I start seeing AFRs in the 11's and 12's so that the extra fuel is delivered right before entering boost.

I hope this helps (2thumbs)


EDIT: I saw that you mentioned that you were interested in other MSP's, but I hope my data still helps. Also, I have the AEM UEGO Wideband.

Thanks alot. That actualy helps alot. Mine just does about that, give or take. How about when you put the clutch in around 3k and the rpms drop, does it go rich (like 10.x) for a bit but recover in about 3 seconds?

 

[KrayzieFox]

Thanks alot. That actualy helps alot. Mine just does about that, give or take. How about when you put the clutch in around 3k and the rpms drop, does it go rich (like 10.x) for a bit but recover in about 3 seconds?

Mine's automatic, so no clutch for me but if I pop it in N and coast it does the same thing as I'm slowing down. At first the AFR's go super lean and show --- as I let off the gas, then as slowing down they get super rich and show 10.x like you said, but mine recover in about a second or less and hang out in the stoich 14.5-15.2 range.

 

[MSPM1cheLe]

Mine's automatic, so no clutch for me but if I pop it in N and coast it does the same thing as I'm slowing down. At first the AFR's go super lean and show --- as I let off the gas, then as slowing down they get super rich and show 10.x like you said, but mine recover in about a second or less and hang out in the stoich 14.5-15.2 range.

awesome. very good info thank you so much. Sounds like its running about normal then. My car has improved quite a bit, though, still not running as good as it should be because there will be times when it will dip down to a real low rpm, like 450 and the engine will stumble and be stuck at a 8.x - 9.x
ratio. not sure what's causing this. Maybe someone would know? Or perhaps the ecu gets the real low rpms signal and then tries to correct it by pouring more fuel in?..... Not sure.

like i said earlier in the thread i checked my o2 sensors and they are all fine, sooo... not quite sure what else it could be.

 

[Deatschwerks]

Lower the RPM, the lower the pulsewidth.. i.e. My car is running at .68 MS at idle. That is a very very small amount of fuel. You might have a leaking injector, if you are running rich at low RPM's like that

 

[MSPM1cheLe]

Lower the RPM, the lower the pulsewidth.. i.e. My car is running at .68 MS at idle. That is a very very small amount of fuel. You might have a leaking injector, if you are running rich at low RPM's like that

it kind of seems like it bc when it dips down that low, the rpms start bouncing when it tries to catch up. how do i check my injectors?


and i also just bought some injector/fuel system cleaner so i will toss that in there next time i fill up.

 

[lyserjic]

it kind of seems like it bc when it dips down that low, the rpms start bouncing when it tries to catch up. how do i check my injectors?


and i also just bought some injector/fuel system cleaner so i will toss that in there next time i fill up.

I was having a very similar issue with my MSP, stumbling idle as you describe, REALLY bad when things warmed up. Constant CEL with P0171 & P0300 (bank 1 lean and random multiple misfires).

Pulled the fuel pump this past weekend. Here's where it got interesting. The large gasket around the output side of the fuel pump was crumbling into bits. Replaced pump & gasket. Starting issue stopped immediately and CEL went away in 24 hours. And it passed my state emission test this morning.


If you look at the number of people on here having these very same issues, it makes me wonder how many bad fuel pumps there are out there. The pump can be real pain to remove if you don't take the proper precautions BEFORE stripping those crappy 9 screws. I did mine in about 30 minutes, thanks to information on here. While I was at it I replaced those crappy screws with stainless hex bolts..

-Lyserjic
SpicyO #1291

 

[MSP2k3]

I was having a very similar issue with my MSP, stumbling idle as you describe, REALLY bad when things warmed up. Constant CEL with P0171 & P0300 (bank 1 lean and random multiple misfires).

Pulled the fuel pump this past weekend. Here's where it got interesting. The large gasket around the output side of the fuel pump was crumbling into bits. Replaced pump & gasket. Starting issue stopped immediately and CEL went away in 24 hours. And it passed my state emission test this morning.


-Lyserjic
SpicyO #1291

When i first bought my MSP, i was having stumbling problems as well, but only under load. I got the exact same CEL's the bank 1 lean and random multiple misfires. I had my entire fuel pump assembly replaced and it cured the problem completely. Car has run great since.

 

[KrayzieFox]

I was having a very similar issue with my MSP, stumbling idle as you describe, REALLY bad when things warmed up. Constant CEL with P0171 & P0300 (bank 1 lean and random multiple misfires).

Pulled the fuel pump this past weekend. Here's where it got interesting. The large gasket around the output side of the fuel pump was crumbling into bits. Replaced pump & gasket. Starting issue stopped immediately and CEL went away in 24 hours. And it passed my state emission test this morning.


If you look at the number of people on here having these very same issues, it makes me wonder how many bad fuel pumps there are out there. The pump can be real pain to remove if you don't take the proper precautions BEFORE stripping those crappy 9 screws. I did mine in about 30 minutes, thanks to information on here. While I was at it I replaced those crappy screws with stainless hex bolts..

-Lyserjic
SpicyO #1291

Kansei from TMF had the exact same thing happen to his P5 as well. I'd post a link to it, but the fascist rules of this forum prevent me from doing so.

 

[lyserjic]

When i first bought my MSP, i was having stumbling problems as well, but only under load. I got the exact same CEL's the bank 1 lean and random multiple misfires. I had my entire fuel pump assembly replaced and it cured the problem completely. Car has run great since.

I'm sure it won't be long before I'll be back in there replacing the entire pump assembly. I wasn't all that impressed with the condition of the unit as a whole.

Awfully expensive part too, considering there's not really that much to it.

-Lyserjic
SpicyO #1291

 

[Deatschwerks]

Michelle, We have Walboros if you are gonna replace your stock pump.. just pm me if you need one

 

[Deatschwerks]

it kind of seems like it bc when it dips down that low, the rpms start bouncing when it tries to catch up. how do i check my injectors?


and i also just bought some injector/fuel system cleaner so i will toss that in there next time i fill up.

Cant really check for a leaking injector and know for sure without having them serviced.. but thats up to you. Looks like people have had the same problems as you and know more about MSP's than i do.

 

[MSPM1cheLe]

Hmm okay, interesting stuff. I will have to check out my fuel pump and see if I can see any abnormalties. I don't really think its my pump though, bc i have never gotten a CEL... so that doesn't make as much sense as a leaky injector might. Anyway, Thanks for all your advice. Mark, I'll letcha know id i need anything, thanks