C32 Fuel-pump flow rates
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C32 AMG W203
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Joined: Dec 2007
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From: Corona, CA
03 g35 coupe...........02 c32 Sold
which one did you use and how did you do it? i'm probably pushing 20-22psi
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Joined: Dec 2007
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From: Corona, CA
03 g35 coupe...........02 c32 Sold
i was looking at retroing a new internal one but after looking it our internal pump diy. It seems like too much work.
I think it might be easier to install a second external fuel pump. I thought about just buying one of those high powered denso fuel pumps for supras and rx7 and adding it as a second fuel pump. It should be more then enough to satisfy our fuel needs.
Would it cause too much pressure if i add a second fuel pump? I know the modded rx7 and supra guys run duel pumps.
I think it might be easier to install a second external fuel pump. I thought about just buying one of those high powered denso fuel pumps for supras and rx7 and adding it as a second fuel pump. It should be more then enough to satisfy our fuel needs.
Would it cause too much pressure if i add a second fuel pump? I know the modded rx7 and supra guys run duel pumps.
Junior Member
Joined: Mar 2008
Posts: 23
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C32 AMG W203
You will get lean issue when the map over 4.5V. The best way is clamp MAP to 4.5V. You can use some thing like E-manage BC function do exact setting and keep the max voltage at 4.5V.
You can check my attached picture. Those are my data log.
The Green is MAP, Red is SPEED, Black is RPM and Blue is A/F.
The af1 is before use camp tool. You can see the A/F is lean when MAP
over 130kPa. The af2 is use camp tool. The A/F is slow to lean, but still
under my control. I don't have any ECU tunning. Only do the clamp MAP
and set the fuel pressure at 60psi.
PS: Suggest you install a A/F meter to monitor your A/F after clamp.
If you can use OBDII to check the MAP, it is great.
Last edited by hothbl; Apr 29, 2010 at 01:24 PM.
Junior Member
Joined: Mar 2008
Posts: 23
Likes: 0
C32 AMG W203
i was looking at retroing a new internal one but after looking it our internal pump diy. It seems like too much work.
I think it might be easier to install a second external fuel pump. I thought about just buying one of those high powered denso fuel pumps for supras and rx7 and adding it as a second fuel pump. It should be more then enough to satisfy our fuel needs.
Would it cause too much pressure if i add a second fuel pump? I know the modded rx7 and supra guys run duel pumps.
I think it might be easier to install a second external fuel pump. I thought about just buying one of those high powered denso fuel pumps for supras and rx7 and adding it as a second fuel pump. It should be more then enough to satisfy our fuel needs.
Would it cause too much pressure if i add a second fuel pump? I know the modded rx7 and supra guys run duel pumps.
MBWorld Fanatic!
Joined: Dec 2007
Posts: 5,034
Likes: 6
From: Corona, CA
03 g35 coupe...........02 c32 Sold
The easy way is use 4.3V ZD to clamp it. 4.3V cheat ECU around 17-18 psi.
You will get lean issue when the map over 4.5V. The best way is clamp MAP to 4.5V. You can use some thing like E-manage BC function do exact setting and keep the max voltage at 4.5V.
You can check my attached picture. Those are my data log.
The Green is MAP, Red is SPEED, Black is RPM and Blue is A/F.
The af1 is before use camp tool. You can see the A/F is lean when MAP
over 130kPa. The af2 is use camp tool. The A/F is slow to lean, but still
under my control. I don't have any ECU tunning. Only do the clamp MAP
and set the fuel pressure at 60psi.
PS: Suggest you install a A/F meter to monitor your A/F after clamp.
If you can use OBDII to check the MAP, it is great.
You will get lean issue when the map over 4.5V. The best way is clamp MAP to 4.5V. You can use some thing like E-manage BC function do exact setting and keep the max voltage at 4.5V.
You can check my attached picture. Those are my data log.
The Green is MAP, Red is SPEED, Black is RPM and Blue is A/F.
The af1 is before use camp tool. You can see the A/F is lean when MAP
over 130kPa. The af2 is use camp tool. The A/F is slow to lean, but still
under my control. I don't have any ECU tunning. Only do the clamp MAP
and set the fuel pressure at 60psi.
PS: Suggest you install a A/F meter to monitor your A/F after clamp.
If you can use OBDII to check the MAP, it is great.
After reading the kenne bell stuff, i might just make my own fuel pump booster if the tuning fails. I did the research and I can build my own fuel booster for around $5.
I'm hoping a increase in fuel flow will fix the lean issue or should i really be looking at the fuel pressure rail?
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Joined: Dec 2007
Posts: 5,034
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From: Corona, CA
03 g35 coupe...........02 c32 Sold
ok did a custom dyno tune with eurocharged tuning remotely and dynoing a DCperformance.com.
Major props for aaron only charging me 1.5hrs of dyno time when it was really 4hrs.
4hrs of dyno tuning and my power still sucks but i got the afrs down. The fuel line is still junk going from a 10.2 toping out at 12.5 on the last run.
fuel pressure measured 60psi went down slightly to 58psi at 150mph.
So i guess the others are right, the stock fuel system seem satisfactory. I'm going back on friday to try to fix the fuel curves. At least i dont have to worry about my motor blowing up anymore.
current mods EC 185mm pulley, EC headers, code3 intake, code3 heat exchanger, ngk colder step spark plugs.
Major props for aaron only charging me 1.5hrs of dyno time when it was really 4hrs.
4hrs of dyno tuning and my power still sucks but i got the afrs down. The fuel line is still junk going from a 10.2 toping out at 12.5 on the last run.
fuel pressure measured 60psi went down slightly to 58psi at 150mph.
So i guess the others are right, the stock fuel system seem satisfactory. I'm going back on friday to try to fix the fuel curves. At least i dont have to worry about my motor blowing up anymore.
current mods EC 185mm pulley, EC headers, code3 intake, code3 heat exchanger, ngk colder step spark plugs.
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Member
Joined: Oct 2007
Posts: 121
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C32 AMG
Got a fuel pump question. I had the car not start recently (cranks fine but wont start, even cold so it's not CPS/CamPS). MBSM tells me it's my fuel pump but they need to replace the whole fuel delivery system? Like gas tank, pump and lines - $3200. Does it seem right?
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Joined: Feb 2009
Posts: 13
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1970 Buick GS 455
Fp dropping down from 60 to 58 would indicate a very mild inadequacy in fuel pump capacity, but certainly not enough to be worriesome, it just indicates that you are just barely starting to exceed the fuel pump's ability. More inj DC% (or pulsewidth) will further exaggerate this as it means more fuel is being demanded.
ok did a custom dyno tune with eurocharged tuning remotely and dynoing a DCperformance.com.
Major props for aaron only charging me 1.5hrs of dyno time when it was really 4hrs.
4hrs of dyno tuning and my power still sucks but i got the afrs down. The fuel line is still junk going from a 10.2 toping out at 12.5 on the last run.
fuel pressure measured 60psi went down slightly to 58psi at 150mph.
So i guess the others are right, the stock fuel system seem satisfactory. I'm going back on friday to try to fix the fuel curves. At least i dont have to worry about my motor blowing up anymore.
current mods EC 185mm pulley, EC headers, code3 intake, code3 heat exchanger, ngk colder step spark plugs.
Major props for aaron only charging me 1.5hrs of dyno time when it was really 4hrs.
4hrs of dyno tuning and my power still sucks but i got the afrs down. The fuel line is still junk going from a 10.2 toping out at 12.5 on the last run.
fuel pressure measured 60psi went down slightly to 58psi at 150mph.
So i guess the others are right, the stock fuel system seem satisfactory. I'm going back on friday to try to fix the fuel curves. At least i dont have to worry about my motor blowing up anymore.
current mods EC 185mm pulley, EC headers, code3 intake, code3 heat exchanger, ngk colder step spark plugs.
and the injectors are the same on the E55 where they are flowing fuel to maintain more then 500 whp, so it is all in the ECU, rich loose some power lean get more power, this is our ecu.
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Joined: Dec 2007
Posts: 5,034
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From: Corona, CA
03 g35 coupe...........02 c32 Sold
i'm pretty confident the injectors are fine. I have a newer engine with 60k on it. I think its just the tune because i was hitting 15afr and not its 11-12.5afr.
MBWorld Fanatic!
Joined: Dec 2007
Posts: 5,034
Likes: 6
From: Corona, CA
03 g35 coupe...........02 c32 Sold
we have in tank fuel pumps. The dealership wants to swap out the whole thing to get more money from you. You can just swap out the fuel pump. Its around $400 and located in the rear seats. There's a diy on the w203 forum.
MBWorld Fanatic!
Joined: Dec 2007
Posts: 5,034
Likes: 6
From: Corona, CA
03 g35 coupe...........02 c32 Sold
What was your injector duty cycle during these runs? Seems like you need more injector pulsewidth to get that 12.5 down to a safer level. Try to tune for closer to 100% DC in the upper rpms.
Fp dropping down from 60 to 58 would indicate a very mild inadequacy in fuel pump capacity, but certainly not enough to be worriesome, it just indicates that you are just barely starting to exceed the fuel pump's ability. More inj DC% (or pulsewidth) will further exaggerate this as it means more fuel is being demanded.
Fp dropping down from 60 to 58 would indicate a very mild inadequacy in fuel pump capacity, but certainly not enough to be worriesome, it just indicates that you are just barely starting to exceed the fuel pump's ability. More inj DC% (or pulsewidth) will further exaggerate this as it means more fuel is being demanded.
I'm going to go back from more tuning and post a update.
MBWorld Fanatic!
Joined: Dec 2007
Posts: 5,034
Likes: 6
From: Corona, CA
03 g35 coupe...........02 c32 Sold
yeah i agree. Even the guys at the shop didn't believe we had the same injectors as the e55 until we uploaded the last tune and go my afrs down to 10-12.5
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Posts: 4,152
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From: NJ, NYC
Something Slow
Found this info its in chinese tho but still maybe helpful
it the replacement of the pump only and not the Entire Unit!
http://hibruce.pixnet.net/blog/post/24960412
it the replacement of the pump only and not the Entire Unit!
http://hibruce.pixnet.net/blog/post/24960412
