Strange fuel issue - looking for ideas
#19
EvoM Guru
iTrader: (8)
Heres your fix $112 **** can those 255's buy a single stealth pump on sale from extreme psi make sure you do the rewire and your good for 780hp with a single pump.
https://www.evolutionm.net/forums/ve...fuel-pump.html
https://www.evolutionm.net/forums/ve...fuel-pump.html
Do you have a keyword search setup for Walboro so you can just give the same canned response, that goes against decade plus years of experience?
For the OP: I agree with the others above, you need to figure out what fuel pressure is doing.
#23
Former Sponsor
iTrader: (31)
Ya 780WHP on E85 is absurd. Even a 450LPH walbro is finished around 700WHP on -10 lines.
3Gturbo don't take offense to my response, but on stock wiring a aeromotive 340 vs a modified / pushed in relief valve on a walbro 255 the flow is almost identical.
I did decent testing on fuel pumps and shared all data here: https://www.evolutionm.net/forums/e8...ts-inside.html
3Gturbo don't take offense to my response, but on stock wiring a aeromotive 340 vs a modified / pushed in relief valve on a walbro 255 the flow is almost identical.
I did decent testing on fuel pumps and shared all data here: https://www.evolutionm.net/forums/e8...ts-inside.html
#24
Former Sponsor
iTrader: (31)
Also This cars at my shop.
I did the following so far to troubleshoot it:
We swapped map sensors.
We put in a fresh wideband o2 sensor
We put in fresh pumps and filters
The vehicle had an unprofessional weird fuel hose routing upfront, so i deleted all that for a straight -6.
I switched the stock feed as the new return. (recently I changed this back to the stock feed again to log data.
We re-routed the pressure switch with new wiring & new pressure switch
I unhooked the inline fuel filter and did a 'blow through' test. It seemed fine. I compared it to a brand new kinsler filter we had from another kit and it was identical in pressure.
While the blow through test may not be 100%, it gave me an idea what was going on. We will swap the filter out as well.
The injectors (ID2000) are brand new and hard wired. I will go over the wiring system once again, but the vehicle drives like stock and is perfect, except until it reaches very high RPM with high boost.
If I lower the boost, The issue goes away.
Injector duty cycle is healthy in the 60's.
Alternator is producing 13.5-14 volts at high RPM. Again healthy
Fuel has been added into the fuel map as a 'blanket' to troubleshoot the issue, it simply does not respond to that.
Any further testing we do to the car from here on is at lower boost pressure, where we see the car travel from 11's to mid 12's so it doesn't touch 13 and beyond anymore, since that's not safe territory for the engine.
I also blew out the lines to make sure there was no debri as well.
I have not attached a fuel pressure gauge to the rail yet, ill do that next.
We also bypassed the flex sensor just to see if it was obstructing flow at all, and it was not. We kind of knew it wasn't before we did the test though. Upon disconnecting it, it was clear it is more then free flowing for even 1000WHP+ cars.
I also just to clear my concious started with a fresh rom non FiTRONIC related and same result occured. We also bypassed using the fuel temp sensor and used what was already installed a GM IAT and that had no affect.
So we already trouble shooted a lot of the cars setup so far. I'll connect a fuel pressure gauge to the rail and see what we have going on. It definitely has to be either a voltage issue at the pumps or injectors malfunctioning somehow at higher RPM only, or fuel pressure somehow dropping.
We also swapped a different FPR on as well.
Pretty much everything there is to do we did.
I appreciate help though. If anyone else has suggestions on things that were not mentioned or I didn't check yet feel free to mention them!
I just had another Evo at the shop that had bugs, and I worked that car out 100%.
I did the following so far to troubleshoot it:
We swapped map sensors.
We put in a fresh wideband o2 sensor
We put in fresh pumps and filters
The vehicle had an unprofessional weird fuel hose routing upfront, so i deleted all that for a straight -6.
I switched the stock feed as the new return. (recently I changed this back to the stock feed again to log data.
We re-routed the pressure switch with new wiring & new pressure switch
I unhooked the inline fuel filter and did a 'blow through' test. It seemed fine. I compared it to a brand new kinsler filter we had from another kit and it was identical in pressure.
While the blow through test may not be 100%, it gave me an idea what was going on. We will swap the filter out as well.
The injectors (ID2000) are brand new and hard wired. I will go over the wiring system once again, but the vehicle drives like stock and is perfect, except until it reaches very high RPM with high boost.
If I lower the boost, The issue goes away.
Injector duty cycle is healthy in the 60's.
Alternator is producing 13.5-14 volts at high RPM. Again healthy
Fuel has been added into the fuel map as a 'blanket' to troubleshoot the issue, it simply does not respond to that.
Any further testing we do to the car from here on is at lower boost pressure, where we see the car travel from 11's to mid 12's so it doesn't touch 13 and beyond anymore, since that's not safe territory for the engine.
I also blew out the lines to make sure there was no debri as well.
I have not attached a fuel pressure gauge to the rail yet, ill do that next.
We also bypassed the flex sensor just to see if it was obstructing flow at all, and it was not. We kind of knew it wasn't before we did the test though. Upon disconnecting it, it was clear it is more then free flowing for even 1000WHP+ cars.
I also just to clear my concious started with a fresh rom non FiTRONIC related and same result occured. We also bypassed using the fuel temp sensor and used what was already installed a GM IAT and that had no affect.
So we already trouble shooted a lot of the cars setup so far. I'll connect a fuel pressure gauge to the rail and see what we have going on. It definitely has to be either a voltage issue at the pumps or injectors malfunctioning somehow at higher RPM only, or fuel pressure somehow dropping.
We also swapped a different FPR on as well.
Pretty much everything there is to do we did.
I appreciate help though. If anyone else has suggestions on things that were not mentioned or I didn't check yet feel free to mention them!
I just had another Evo at the shop that had bugs, and I worked that car out 100%.
#25
Evolved Member
iTrader: (22)
External fuel pressure gauge coming out of the hood near the windshield. Watch what happens when you get to higher RPM. The pressure will tell the story.
Also, Ive seen pumps push gas at the pump outlet hose. So in higher rpms you lose pressure. Lower RPMs your fine.
Also, Ive seen pumps push gas at the pump outlet hose. So in higher rpms you lose pressure. Lower RPMs your fine.
#26
Former Sponsor
iTrader: (31)
Were switching the injectors out first for a set of FIC since I want to get these off his car. This is the second car now that had bad ID's. The white Evo had a brand new set of ID 2000 and they were bad right out of the packaging. Thankfully the place that sold them returned them without an issue. It seems to be hit or miss, I do a lot of evo with ID without issues, then we get some that have issues.
If injectors don't fix it I'll check the pressure, but that wont tell me the issue. It can show up in the pressure as it most likely will, but a weak pump can trigger that pressure issue if you get what I'm saying.
So its kind of going to be already telling us there's a pressure issue when we already know one exists (at least 99% sure, but of course we need to be 100% sure to responsibility diagnose).
Bosch 2200cc inj have a non stainless internal housing, so if moisture gets anywhere near them they can rust and lock up. Both ID2k and FIC 2150 are prone to this if not taken certain steps.
I've had FIC 2150 on my evo for roughly 6-7 years and never had an issue with them, but they always stay in my car and were never stored outside the plenum for the most part.
If injectors don't fix it I'll check the pressure, but that wont tell me the issue. It can show up in the pressure as it most likely will, but a weak pump can trigger that pressure issue if you get what I'm saying.
So its kind of going to be already telling us there's a pressure issue when we already know one exists (at least 99% sure, but of course we need to be 100% sure to responsibility diagnose).
Bosch 2200cc inj have a non stainless internal housing, so if moisture gets anywhere near them they can rust and lock up. Both ID2k and FIC 2150 are prone to this if not taken certain steps.
I've had FIC 2150 on my evo for roughly 6-7 years and never had an issue with them, but they always stay in my car and were never stored outside the plenum for the most part.
#27
Evolved Member
iTrader: (22)
A more accurate statement is: knowing the pressure will lead you in the right direction. (I call it checking the box) If your pressure is good then it limits the amount of things you get to test.
Its very odd to say, but it sounds like its the injectors.
Keep us updated.
Its very odd to say, but it sounds like its the injectors.
Keep us updated.
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tscompusa (Apr 23, 2016)
#30
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Join Date: Jan 2014
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I dont understand the "evo guys are so cheap" reference?
My transmission is worth as much as a 3G