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KFred 513

Proven Member
146
0
Oct 11, 2012
SUllivan, New_York
So i'm on a fresh engine, full build top to bottom, idle and cruise tune will work for now until I put the permanent injectors in. My problem is that as soon as I approach boost/put any load on the engine it is starved of fuel.

So far I have:
Swapped in another known working pump (AEM 320LPH)
verified 1:1 rise at the regulator with air compressor
verified fuel filter installed in proper flow direction and not clogged
fabbed a fitting for the sending unit to use fuel line and hose clamps to attach pump
verified 12V at pump with it running,
14+Volts coming from alternator at idle

SD VE adjust keeps wanting to raise the cells in the 3500 rpm column, where the car goes lean. You can see where it is on the VE table. We have tried adding 50% fuel via sliders in that area to see if the car would richen at all, but it doesnt. I don't believe the problem is tune related, I think it is a mechanical issue, but didn't know where else to put my thread. I am just out of ideas, and every other thread is a dead end or my car checks out with their issue. Any help or ideas is appreciated.

Edit: I just went over every tab from the log and noticed DTC p1500. I just broke 100 miles on the new setup, and searches show that it takes 100 miles before people get the code. I rewired the entire charge system with a saturn alternator and removed the wiring to pin 41 at the ecu. If pin 41 on the ecu is not wired correctly, could this cause the ecu to not know how many volts are in the system and result in my problem?

In my log you can see where the problem happens at 136 seconds
 

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I noticed as the ECU goes into open loop it also goes into idle control as well. Try checking the box 'Disable Idle Switch While Moving' and see what happens. What size injectors btw?

Not sure on the DTC code. I know there is sometimes an issue with that code on 2Gs. I used to get it on mine as well, would go away after a quick rev. There is a way to disable it(which I did) but I dont remember how to off hand.
 
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Check for any exhaust leaks before the o2 sensor yet?
 
We actually did try disabling the idle switch on thebfirst night of trouble shooting. It didn't help. I changed my openloopthreshhold to force the car to idle in open loop. Closed loop idle has never been fun in my car. The Q45 TB is mostly to blame I think.

If other cars drive fine with the error code, I doubt rewiring mine will solve the problem. I know my charge system is working properly, I just dont know for sure if the ecu needs to see voltage at pin41.

I do have a slight exhaust leak at the head flange. I need to get it milled flat. However, I don't think it is causing my problem. Along with the wideband going lean, the car stumbles. These symptoms persist when increasing fuel by 50% in link.
 
You've got a hell of a problem on your hands, I've been thinking about this for awhile and have comeback to it a few times and each time pulling a blank. You've done everything I would have done leading up to this point so now it's time to get creative, or we're both missing something.

At first I questioned the WB but the car is going lean, which can be verified by the front o2 voltage going lean too. I'd move my search up into the fuel injectors, maybe one of them stops squirting once it hits a certain duty cycle which is ~20% looking at your log. Personally, I'd check the injector resistor pack with a multimeter and see if it's in spec and then ohm out the injectors and maybe you'll find something. If not, try kicking your base fuel pressure up to 50psi and doing a similar log. Kicking up base fuel pressure will increase your injector size so you'll have to account for it in your globals but by doing this you won't hit 20% IDC until later in the powerband so you can see if the lean problem still occurs at that boost level or moves with the IDC's.

Just to save you the trouble... Those 550's on 50psi BFP will flow 590cc/m so will require a global of -25%.
 
Thanks gofer, I think your on the right track with the injectors. I actually just swapped in a set of borrowed 1200cc injectors to see if the other set just isn't flowing what they should be. If the problem persists I will give your method a shot to see what the results yeild. Did you use the calculator in link tools to get those numbers?

I was going to take the car for a test ride but....dead battery. thats where the p1500 code must have been coming from. My red top sat for a year with about 7V on it. AutoZone charged it for me and said it tested good, but I think not. I should have another battery to swap in tomorrow.

Ill report back with results when I have them
 
My problem is that as soon as I approach boost/put any load on the engine it is starved of fuel.

When you replaced the fuel pump, did you notice the fuel sock containing excess debris? I had a similar problem that ended up being a dirty fuel tank clogging the fuel sock. It would allow me to idle and drive out of boost with no problem but once the load reached a certain point, it would lean out due to the restrictive fuel sock.

If everything else checks out, try getting a spare fuel line from the filter to the rail, insert a T and run some line to a fuel gauge. Hold the gauge out the window (we dont want raw fuel in the cabin) and go for a ride. As boost increases the gauge should too. I know that you have checked the AFPR and you have replaced the pump but if something is restricting the pump then pressure may not rise as expected.
 
Thanks Robert, the fuel sock is brand new. I replaced it when I put the first AEM 320. I swapped the new sock onto the replacement pump.

I have also been wondering if the pressure is not rising while driving. I'm going to try these new injectors, but if they don't solve the problem I need to look into a remote gauge of some sort. I would like to just run a line off the extra port on the regulator...that should be fine right?
 
I assumed you already tested the AFPR rose with boost...

So far I have:
Swapped in another known working pump (AEM 320LPH)
verified 1:1 rise at the regulator with air compressor
verified fuel filter installed in proper flow direction and not clogged
fabbed a fitting for the sending unit to use fuel line and hose clamps to attach pump
verified 12V at pump with it running,
14+Volts coming from alternator at idle
If that's not the case you don't have to go through all the trouble of routing a fuel line to the gauge and holding it out the window. Although, if you do want to do it be sure to get a video. LOL

Since you have ECMLink just keep the car off but turn the key to "ON" and activate the fuel pump through Link. Then connect your air compressor to the AFPR and see if fuel pressure rises 1:1 with "boost" that you're simulating with the air compressor.

I do like your idea though, Robert. ;)
 
I had a similar issue lately. Ended up the guage on my AFPR was off a little. First I removed my hood and put a go pro on my fender and went for a short drive. Got into boost to record the AFPR gauge to see if it rose with boost. I then added base fuel pressure on the AFPR and my issue went away. I put a new gauge on the AFPR and my problem is solved with correct base FP. That gauge was less than 6 months old too.
 
I do like your idea though, Robert. ;)

I had to do this before I had access to an air compressor on a stock FPR.... guess I should have taken a video. Thanks for correcting my asinine post (considering he has safer alternatives). :thumb:

No need to hack up a line, as the method listed below is much safer and hassle free.

Since you have ECMLink just keep the car off but turn the key to "ON" and activate the fuel pump through Link. Then connect your air compressor to the AFPR and see if fuel pressure rises 1:1 with "boost" that you're simulating with the air compressor. ;)

If this is what you have already done then the fuel delivery up to the injectors is acting as it should. Actually driving will yield the same results.
 
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I did confirm that pressure rises with an air compressor on the regulator and the pump.

I'm trying to figure out how to say what's in my head haha. With the air compressor test, the engine is not consuming fuel. Once I'm driving the car, fuel is being consumed, so even if the pressure is there, volume may not be.

I would like to think that the air compressor test would tell me fuel supply is adequate but is it really fail proof?

I may try the "fill a bucket" test and see if its flowing what it should be.
 
The math of VE through AFRest of "(Table VE * Logged Wideband)/Logged AFRest" says to lower the cells. There still may be something mechanically wrong though, it shouldn't drop that drastically. While looking over whats different between what you have and what I had, your load scale is different you changed it to 100% should be 114.8% I think http://www.ecmtuning.com/forums/showthread.php?p=434014#post434014
 
I may try the "fill a bucket" test and see if its flowing what it should be.

That is your best bet. Pressure is a measurement of restriction to flow (inversely proportional to it in fact). The only true way to know how much fuel you are actually flowing is to measure the volume of fuel delivered to the rail.

If you get bored, try the same flow test after bypassing the fuel filter. Like ignition coils, testing a fuel filter can only prove that it is bad... not that it is good. It may seem fine at a certain pressure/flow, but fall on it's face when the demands go up.
 
Thanks for the link Zane. I'd be lying if I said I understood all the tech talk in that thread, but it seems that the new firmware update is intended to run 100% loadfactor where the old firmware was 114.8%. Am I correct in thinking that? There still has to be another problem because regardless of that setting the mixture should richen when adding 50% to the sliders above 3000rpm.

My battery tested bad today so I'm picking up a new one after work and I'll try out these 1200cc injectors. Is it possible that the dead battery was swallowing all the voltage coming from the alternator and causing my fuel pump/injectors to see low volts? Keep in mind my volt gauge shows 14+V at all times with the car running

Craig I'll be trying the bucket test if the new battery and injectors don't fix the issue. I also want to or place the AFPR gauge. If its bad and my base pressure is totally wrong maybe that could be the problem like someone else mentioned

My battery is in the hatch wired in this order. 2gauge fine copper strand from alternator to moroso kill switch> 2g from same lug as alt to circuit breaker> other side of circuit breaker to battery. From the 'on' side of moroso switch directly to distro block that feeds 2 4g wires to fuse box and one 2g wire to starter. Alt sense wire is tied into distro block, volt gauge feed is from fuse box power feed.
Fuel pump gets power directly from battery terminal
 
Does that pump have a rewire kit on it still? If so its possible. (Edit: I just saw it in your last sentence)
 
I reread that thread and I get it now. The 100% load scale is fine because I'm starting with a fresh VE map. If I was trying to use the old VE map and I only changed the load scale, the tune would be off.

As an update:

I bought a new battery tonight and put it in. The battery did not help, although it puts out more volts with the car off than the tired red top did.

I decided to test flow with the bucket method. The pump is rated at 330LPH at 40psi fuel pressure and 13.5V. The battery put out about 12.2, and I left the regulator set at 43 psi, both inhibiting flow. The pump gave me 3.5L of gas during a 1 minute test. 3.5L X 60min= 210LPH. With the lower voltage and more restriction from the regulator I'm not surprised with the numbers and 210LPH is more than enough fuel to prevent my car from going lean at 3000rpm and no boost.

I also put a different gauge on the regulator and it confirmed the base fuel pressure being at 43psi.

I didn't try the 1200cc injectors, I put the evo 560s back in. Im not sure of the condition of the 1200s so I am skeptical. I will try Otters suggestion tomorrow and adjust the base pressure higher and injector settings.

I have some things running through my head, maybe someone with experience can provide some insight.

Has anyone ever had injectors act normal in vacuum, but fail to provide enough fuel above base pressure?

I'm now wondering if this is a spark issue rather than a fuel issue. The car has an MSD Dis2 and COP, but the problem persists with the MSD bypass plug installed. I just rebuilt the COP harness and used butt connectors, solder, and heat shrink on all joints.

heres another log. all the settings should be the same.
 

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Well as an update for today...

I checked the injector pack with a meter and all positions gave me about 6ohms which is within limits.

I also pulled the ECU out and checked both sides for anything out of place, all looked well.

I really need to swap out injectors but that might be a while unless I decide to try the 1200s which im not sure if I want to. Other than otters fuel pressure bump idea, does anybody have anything?
 
Does your Saturn alt only have a 2 pin connector instead of the stock 4 pin? If so, your not driving ECU pin 41 which I think your P1500 is coming from. It won't affect charging, it just won't control the IAC based on alt load (which the stock 4 pin one does) so you'll get annoying P1500's.

Does your Saturn alt put out 14+ volts at the battery? If not you have a problem. Make sure your dash charge (battery) light is working and you have positive voltage on the alt "L" terminal (or the alt won't turn on).

For sensor ground issues you need to check that the harness wire going into ECU pin 92 is not grounded anywhere else (except inside the ECU) which it should not be (for 2g ECU pinout: 2G Turbo ECU Pinouts). If grounded (or low resistance) elsewhere, that indicates an improper sensor connection (or shorted sensor) which may cause the ECU's pin 92 to carry a high current which should not be there. Disconnect battery negative cable and then unplug the ECU. Now with meter set to resistance put the minus (or common) lead to ground (bare metal on body or frame) and the positive lead to the harness side connector's pin 92. You should read infinite. Now leaving the one lead on ECU pin 92, place the other lead on the battery + cable terminal (leaving + connected to the battery is ok since battery negative is disconnected) to check for a short to +12V. You should read infinite (or a very high value).
 
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Thanks luv2rallye. I have an AEM volt gauge. The gauge is wired into my distribution block which is fed power from the battery. The gauge always shows 14+ V with the car running. The alternator is for sure doing its job

I have the 3 pin connector at the alternator. I confirmed that I don't have pin 41 at the ecu connector, removed when I went through the harness. Since I don't run an ISC I'm not worried about that.

I will be trying your tests asap. Since my fuel system checks out in all aspects I think it must be a sensor/grounding issue. I'm going to make a brass buss bar to bolt all of the grounds individually and run a main ground wire from the battery to the bar.

Is it fine to bolt all body grounds to the buss bar? I see many people saying that the grounds need to be spread out...but I think that is just a misunderstanding. The path of least resistance is the best way, which in my case would be the buss bar correct?
 
Thanks Brian. My next move is going to be new coils. I'm wondering if the spark is weak at one or more coils (COP). The spark could be strong enough to let the car idle and drive in vacuum, but as soon as cylinder pressure rises, the spark can't ignite the mixture.

I do have a bit of a fuel smell from the oil fill caP. Probably some unburnt fuel getting past the rings which might not be seated yet. It just seems too unlikely for multiple injectors to be that clogged shortly after being removed from a running car. I Won't be able to try until the weekend so I'll report back when I have more info.
 
Nice job on the fuel testing and troubleshooting. Good to see someone going about it properly for a change. ;)

FWIW, I fought with bad coils for a long time. I went through set after set of "good" used coils, COP setups, CDI boxes, etc. I finally bought all new coils from Rock Auto for like $25 each, got rid of the COP, and my ignition has been golden ever since.
 
Nice job on the fuel testing and troubleshooting. Good to see someone going about it properly for a change. ;)

FWIW, I fought with bad coils for a long time. I went through set after set of "good" used coils, COP setups, CDI boxes, etc. I finally bought all new coils from Rock Auto for like $25 each, got rid of the COP, and my ignition has been golden ever since.

Thanks craig. What kind of symptoms did you see with the bad coils? I'm at my wits end, I don't know what else to try. I'm wondering if I should just put a stock coil/wire setup on the car for testing purposes. We bypassed the MSD when we first noticed the car going lean but the problem persisted so it is plugged back in.

Since my last post I have:

tried a known good set of injectors (Bluemaxx 1650s).
swapped in a known working injector transistor pack
known working CAS
verified all sensor grounds are properly wired
I also did the checks suggested by luv2rallye but all checked out.
bypassed fuel filter just as an extra precaution
put in two sets of junkyard intrepid coils (both sets may have had a bad coil????)

I'm tempted to get a fuel pressure sending unit and put in on my AFPR, and monitor it in link. I'm also thinking about ordering a walbro 450 to replace this "used" AEM 340LPH. This is the second AEM pump ive tried, but both were used and had sat for a while before I got my hands on them.

here is a more recent log from this week.

EDIT: So I decided to read up on the AEM pump a little and found a flow chart. I'm not sure where I came up with the previous rating but I was off by a lot. The flowchart that AEM advertises with the pump says At 80 psi of fuel pressure, my pump should be flowing more fuel than it was at 43psi. Once I found that I ordered a walbro 450. I'm hoping this takes care of the issue finally, I refused to believe that 2 fuel pumps in a row could be bad, but time will tell.
 

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Update:

I got my 450LPH and rewired it to ensure proper voltage/current.

I also ran a 4awg cable from battery negative to my buss bar and then directly to the head

Swapped in a factory set of coils and wires,and removed the MSD DIS-2.

removing the MSD seems to have helped some, but the car still goes very lean under hard acceleration.

I have to start load testing the harness because I have a bad feeling that something may have went wrong with a connection that I crimped/soldered.

I also noticed that my PTU gets extremely hot while driving, too hot to touch. Is this normal? If not, I'm assuming it is because of extra resistance from a poor connection.
 
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