Stradag

iTrader: (17)

Solved bad spark plug wires. Thanks for all the input everyone!






I have been working on my car for a while. Previously the car ran great. Then out of no where it went from a very consistant 11.7 Afr to 12.0 12.5 somtimes 13.0 AFR. So, we tried adjusting the fuel map and it did not do anything at all.
The fuel map is pretty much set to as rich as it can go 7.4 afr, and the boost is at about 1-1.3 bar, but the afr stays lean.
I checked all of the vacuum hoses, boost leaks, exhaust leaks, intake leaks. I changed the fuel pump to a band new walbro. My old fuel pump was a walbro that was in there for about 5 yrs.
The Wideband reads a pretty consistant 14.7 AFR at idle and cruise (just installed new wideband sensor also) , but when I go WOT the car starts misfiring pretty bad and goes lean. I have a couple logs available if anyone is interested in taking a peek. You can see in the logs the IDC is at 100-113%, even at 1 bar!!
I have checked all the relays except for relay 3 on the firewall. (I hooked up relay three to the battery and it does click like it should, I also checked the transistor and I got 6.2 ohms on the injector pins) I dont have one to swap out to see if it makes a difference.
When I installed the new walbro the afr went slightly richer but IDC is still maxed.
PLEASE HELP!!!!

Current DTC are P0401 and P0441.
Tried EGR block off no difference.
Reset CEL with evoscan has not come back on yet. drove approx 200 miles.
Tried deleting all emission components no difference, also zip tied all vac hoses.
Replaced all Fuel Filters no difference
Replaced FPR no difference
Switched to 94170015 Rom no difference
Tried boost leak test good
Compression test good
spark plug wires switched from magnecore to stock - problem solved

2003 Evo VIII

MODS
HKS RS Intake pipe kit
Dejon UICP, EBAY LICP
Synapse BOV Recirculated
Grimmspeed EBCS
EPM Ext. o2 Dump
Evo IX Turbo
HKS 280 Cams
TBE
New Walbro Fuel Pump
Magnecore Wires
BPR8es Plugs
HKS EIDS Hooked up but disabled

GST Motorsports

iTrader: (8)

I would lean towards the fuel filter in the pump assembly (white plastic) being clogged. It happened on my personal Evo and reacted the same way.



What CEL is the car throwing?

- Bryan

Stradag

iTrader: (17)

p0401 and p0441. Where is the fuel filter in the housing?

Stradag

iTrader: (17)

Anybody else ever have a exper. like this with a evo?

Mautofied.IS300

iTrader: (12)

I would trust Bryan from GST, and he said he experienced the same thing. Have you checked your fuel filter yet? Check out the walbro install how to in order to picture it.

P0401: EGR Flow Insufficient Detected
P0441: Evaporative Emission Control System Incorrect Purge Flow

Here is a thread on P0441:

https://www.evolutionm.net/forums/ev...elp-p0441.html

-Will

sponners

I experienced similar and it was due to a blocked fuel filter (not the one on the pump)

fostytou

iTrader: (15)

They are talking about the filter on the return. It is the other assembly under the other panel in the rear seat opposite the fuel pump. You have to buy the whole assembly for ~$130 and cannot just buy the filter.

GST Motorsports

iTrader: (8)

Actually I am talking about the filter in the pump assembly. It's integrated into the white plastic assembly that holds the fuel pump. You have to buy the whole assembly.

The return on the other side has a little barrel filter, more like a strainer, that hasn't had issues yet.

Fuel Pump Assembly:



The internal filter within the assembly:



- Bryan

Stradag

iTrader: (17)

NICE THANKS FOR THE PICTURES....I PURCHASED A NEW FILTER FOR THE OTHER SIDE SINCE IT WAS ONLY 10 BUCKS (BTW I ORDERED IT FROM DODGE LOL) . i FOUND A FUEL PUMP HOUSING ON HERE WITH 7K ON IT IM GOING TO DO A FUEL PRESSURE TEST AND CHECK THE AMPERAGE ON THE FP FUSE, IF IT IS INFACT CLOGGED IT SHOULD BE PUILLING MORE AMPS I BELIEVE.

Stradag

iTrader: (17)

Does anyone know how may amps my fuel pump should be pulling? I have a new waboro 255 and i checked the amps today and its pulling 5.70 amps isnt that kinda high? I read in the auto mag at work that most cars pull 1 to 5 amps. It said if its pulling anymore than that its most likely a clogged filter. Thanks

Kilratio

iTrader: (16)

sounds like you got your answer. Let us know the outcome. I've been having weird break ups also but I think mine is the MAF. good luck.

Stradag

iTrader: (17)

I FOUND THIS FLOW CHART BUT IT DOESNT MATCH WITH WHAT MINE IS RUNNING AT. DOES ANYONE ELSE HAVE ANY INPUT? IS ANYBODY UP TO CHECK THE AMPERAGE AT THE FUEL PUMP FUSE AT IDLE, SOMEONE THAT HAS A WALBORO INSTALLED?

Stradag

iTrader: (17)

Changed out all the fuel filters.....fuel pump housing, strainer and feed line from other side of tank strainer, and AFR is still as lean as can be with fuel maps set to 7.4. I guess I am going to try replacing the FPR next.

Stradag

iTrader: (17)

replaced the fpr and it seemed to get a tad better but its still runing lean, any other suggestions? I am lost

jimmy79

EVO 5 but similar problem?

http://www.lancerregister.com/showthread.php?t=257029