Soft fuel cut under boost 2.3L evo 9 Help appreciated!
Nov 29, 2017, 03:55 PM
#1
Newbie
Thread Starter
Join Date: Dec 2013
Location: salt lake city, utah
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
Soft fuel cut under boost 2.3L evo 9 Help appreciated!
Evo 9
AMS 2.3 Stroker kit (came already assembled from AMS and was dropped in the car)
AMS F1 intake manifold
AMS GT35R
AMS exhaust manifold
ID 1300 (Brand new)
Walbro 450 (Brand new)
Fuel lab FPR (Freshly rebuilt)
AEM V2
Okada plasma coils (have recently went back to the stock coils and it seemed to have helped)
Cam angle sensor (Brand new)
Crank trigger sensor (Brand new)
Hey guys, long time lurker here.
My brother and I have worked on evos for years, so we are somewhat knowledgeable. I picked up this evo with all the above mods done to it (There are more but these are the ones I figured would be important to list to help me with my issue).
The car has perfect AFR's and has 0 timing errors. The car consistently doesn't like to hit full boost. Right around when boost starts to hit hard (4-5k) the car acts like its not getting fuel. The car doesn't want to accelerate past that 4-5k range.
Bit more background:
Bought the car with all the work done to it by a shop (they didn't do a great job). When I first got the car, it needed a tune badly. Took it to a well-known tuner, put it on the dyno, did some pulls and it did fine on the first pull then we added more fuel and then it went out of whack and didn't want to pull while in boost. Found out the people who put this car together didn't use high-pressure fuel lines and the line was torn at the fuel pump. Car at the time was using a twin Walbro 255 setup (Full blown double pump hangar), changed the setup to the single Walbro 450 for simplicity sakes (only shooting for 450-500 on pump.), replaced the lines, installed fresh plugs, got rid of the big 2200cc injectors (PPE never heard of them), and started to tune again (the rest of the tuning was done by me and my brother). Now the above issue is happening and we cannot figure it out.
We set the tune for about 40 PSI on the fuel pressure, then randomly the pressure went up to about 55 PSI for some odd reason. Figure its the return line getting bent somewhere and building pressure up at the rail.
My next suspect would be the F1 manifold. I dont know of many issues people have with it, but at this point I almost want to sell it for a stock one (again trying to limit issues from having a complicated setup.)
I was hoping for some ideas from you guys that would like to chime in. Sorry for the wall of text.
Let me know what you think. Thank you for your time.
AMS 2.3 Stroker kit (came already assembled from AMS and was dropped in the car)
AMS F1 intake manifold
AMS GT35R
AMS exhaust manifold
ID 1300 (Brand new)
Walbro 450 (Brand new)
Fuel lab FPR (Freshly rebuilt)
AEM V2
Okada plasma coils (have recently went back to the stock coils and it seemed to have helped)
Cam angle sensor (Brand new)
Crank trigger sensor (Brand new)
Hey guys, long time lurker here.
My brother and I have worked on evos for years, so we are somewhat knowledgeable. I picked up this evo with all the above mods done to it (There are more but these are the ones I figured would be important to list to help me with my issue).
The car has perfect AFR's and has 0 timing errors. The car consistently doesn't like to hit full boost. Right around when boost starts to hit hard (4-5k) the car acts like its not getting fuel. The car doesn't want to accelerate past that 4-5k range.
Bit more background:
Bought the car with all the work done to it by a shop (they didn't do a great job). When I first got the car, it needed a tune badly. Took it to a well-known tuner, put it on the dyno, did some pulls and it did fine on the first pull then we added more fuel and then it went out of whack and didn't want to pull while in boost. Found out the people who put this car together didn't use high-pressure fuel lines and the line was torn at the fuel pump. Car at the time was using a twin Walbro 255 setup (Full blown double pump hangar), changed the setup to the single Walbro 450 for simplicity sakes (only shooting for 450-500 on pump.), replaced the lines, installed fresh plugs, got rid of the big 2200cc injectors (PPE never heard of them), and started to tune again (the rest of the tuning was done by me and my brother). Now the above issue is happening and we cannot figure it out.
We set the tune for about 40 PSI on the fuel pressure, then randomly the pressure went up to about 55 PSI for some odd reason. Figure its the return line getting bent somewhere and building pressure up at the rail.
My next suspect would be the F1 manifold. I dont know of many issues people have with it, but at this point I almost want to sell it for a stock one (again trying to limit issues from having a complicated setup.)
I was hoping for some ideas from you guys that would like to chime in. Sorry for the wall of text.
Let me know what you think. Thank you for your time.
Nov 29, 2017, 04:06 PM
#2
EvoM Guru
iTrader: (1)
Are you monitoring fuel pressure when this happens? Is the walbro 450 rewired, or running on stock wiring? Does adding fuel in the tune do anything? What plugs are you running and at what gap? SD or MAF? Boost leak test?
Nov 29, 2017, 04:14 PM
#3
Newbie
Thread Starter
Join Date: Dec 2013
Location: salt lake city, utah
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
The car doesn't have any gauges, we monitor everything through the V2 ECU. Maybe I should look into getting some? I haven't been able to monitor the fuel pressure while driving. We rewired the 450 ourselves, the previous setup was not good. NGK plugs stock gap (I think). The car does use SD. The car had a boost leak test done by a different shop and it looked good (So I've been told). The car also has consistent compression across the board, passed with flying colors.
Nov 29, 2017, 04:17 PM
#4
EvoM Community Team Leader
try raising your load limit?
Nov 29, 2017, 04:48 PM
#6
Account Disabled
Obviously another fuel pressure problem caused by a pump that's too big for the FPR.
Once you pressure test and flow test the fuel system....you'll KNOW.
You don't even need to start the engine to test it all.
Once you pressure test and flow test the fuel system....you'll KNOW.
You don't even need to start the engine to test it all.
Nov 29, 2017, 04:53 PM
#7
EvoM Guru
iTrader: (1)
Pump too big for the aftermarket FPR? GTFO
Last edited by letsgetthisdone; Nov 29, 2017 at 05:29 PM.
Trending Topics
Nov 29, 2017, 04:55 PM
#8
EvoM Guru
iTrader: (1)
The car doesn't have any gauges, we monitor everything through the V2 ECU. Maybe I should look into getting some? I haven't been able to monitor the fuel pressure while driving. We rewired the 450 ourselves, the previous setup was not good. NGK plugs stock gap (I think). The car does use SD. The car had a boost leak test done by a different shop and it looked good (So I've been told). The car also has consistent compression across the board, passed with flying colors.
Absolutely no gauges? Does the V2 have a wideband AFR wired to it?
AEM V2 won't have a load limit per say like stock ECU, but it may have a boost limit/boost cut for over boost that needs adjusted.
Nov 29, 2017, 04:57 PM
#9
EvoM Community Team Leader
P.S. Fuel pressure is love, fuel pressure is life
Nov 29, 2017, 06:04 PM
#10
Newbie
Thread Starter
Join Date: Dec 2013
Location: salt lake city, utah
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
No gauges, no wideband, we can watch the afr's, boost pressure, etc... through the ECU. I myself am not keen on tuning, so I will research more about the boost cut. I do appreciate the input fellas.
Nov 29, 2017, 08:48 PM
#13
Account Disabled
Nov 30, 2017, 06:41 AM
#15
Evolved Member
post a log with manifold pressure and AFR among outher things.. cant diagnose it blind..