Fuel issue?
Fuel issue? I am stumped. I just finished installing a new LS1 5.7 and 4L60 into my 68 RS/SS camaro and i am having some sort of fuel issue. I have tested the fuel pressure at the furl rail and i am seeing 58/60 psi there. i am using the corvette fuel pressure filter\ regulator and a MSD external fuel pump with -6 An and -6 S/S line. My problem is the engine will start and run fine as long as i keep triggering the fuel pump on and off. More off than on? If i leave it on for more than 1 seconds it will kill the motor. I can keep the engine running as long as I cycle the pump wire to the battery very quickly? The pump is on its own wiring system. The engine acts like there is too much fuel? Its acting like the injectors are staying open. the injectors are stock 5.7 This cam crank combo has never ran together. MTIX1 cam and 28x reluctor wheel crank. The guy i purchased the motor from said it ran well until it spun a rod bearing in his CJ5. I believe the ECM has been tuned before. Soon as i can get it straighten out i will put some miles on it to break it in and have it Dyno tuned.
I am getting code PO1336
Here's a thought. Can the ECU be keeping the injectors wide open due to the crank relearn issue? BTW I have taken the fuel rail off the motor and put 58 psi to it and none of the injectors leaked.
I cant wait to get it on the road.
It has 2000 ECU after market harness came with the motor. 02's are hooked up.
Any help would be appreciated.
Where's all the LS Guru's LOL . I am sure this has happened to someone before me...
This is a old picture..
I am getting code PO1336
Here's a thought. Can the ECU be keeping the injectors wide open due to the crank relearn issue? BTW I have taken the fuel rail off the motor and put 58 psi to it and none of the injectors leaked.
I cant wait to get it on the road.
It has 2000 ECU after market harness came with the motor. 02's are hooked up.
Any help would be appreciated.
Where's all the LS Guru's LOL . I am sure this has happened to someone before me...This is a old picture..
Last edited by IntercooledC6; Sep 17, 2011 at 09:12 PM.
PO1336 is the Crank Relearn Code. Can you clear the code, and does it return?
VATS can be an issue, although your signature states that your engine combo has been tuned (and therefore, was previously running). Even though VATS will act to shut off the fuel pump, you've stated that the fuel system runs independently of your computer (so, VATS shouldn't be an issue). Do you have injector signal as verified with a 'noid' light? If no signal, no fuel.
Is it possible that by opening & closing the hot lead, that the on/off surge is helping to keep the pump going??...which might mean that the fuel pump ground is intermittant/poor, and could even point to fuel pump wiring which has a smaller gauge than is required?
Just some stuff to get you going.
VATS can be an issue, although your signature states that your engine combo has been tuned (and therefore, was previously running). Even though VATS will act to shut off the fuel pump, you've stated that the fuel system runs independently of your computer (so, VATS shouldn't be an issue). Do you have injector signal as verified with a 'noid' light? If no signal, no fuel.
Is it possible that by opening & closing the hot lead, that the on/off surge is helping to keep the pump going??...which might mean that the fuel pump ground is intermittant/poor, and could even point to fuel pump wiring which has a smaller gauge than is required?
Just some stuff to get you going.
PO1336 is the Crank Relearn Code. Can you clear the code, and does it return?
VATS can be an issue, although your signature states that your engine combo has been tuned (and therefore, was previously running). Even though VATS will act to shut off the fuel pump, you've stated that the fuel system runs independently of your computer (so, VATS shouldn't be an issue). Do you have injector signal as verified with a 'noid' light? If no signal, no fuel.
Is it possible that by opening & closing the hot lead, that the on/off surge is helping to keep the pump going??...which might mean that the fuel pump ground is intermittant/poor, and could even point to fuel pump wiring which has a smaller gauge than is required?
Just some stuff to get you going.
VATS can be an issue, although your signature states that your engine combo has been tuned (and therefore, was previously running). Even though VATS will act to shut off the fuel pump, you've stated that the fuel system runs independently of your computer (so, VATS shouldn't be an issue). Do you have injector signal as verified with a 'noid' light? If no signal, no fuel.
Is it possible that by opening & closing the hot lead, that the on/off surge is helping to keep the pump going??...which might mean that the fuel pump ground is intermittant/poor, and could even point to fuel pump wiring which has a smaller gauge than is required?
Just some stuff to get you going.
As soon as I connect the fuel pump pos+ wire to the battery it will kill the motor?
If i connect the pump power lead to the battery plus terminal for a split second at a time every 15 seconds or so i will run well? as i say it almost seems like the injectors are running wide open??????
I'm sorry, I skipped/missed part of your 1st post.
Your question..."Here's a thought. Can the ECU be keeping the injectors wide open due to the crank relearn issue? BTW I have taken the fuel rail off the motor and put 58 psi to it and none of the injectors leaked."
Judging by the symptoms, I do think this is related to the issue. I went and read the relearn procedure from my '98' manual, but, other than describing 'crank speed variation', it didn't mention any symptoms such as always-on injectors.
Still, because the code isn't erased, it seems a good place to start.
I'm wondering if a noid lamp would reflect the trouble by showing an 'always-on' LED, or an LED which does more than just flash (as it would normally)?
Your question..."Here's a thought. Can the ECU be keeping the injectors wide open due to the crank relearn issue? BTW I have taken the fuel rail off the motor and put 58 psi to it and none of the injectors leaked."
Judging by the symptoms, I do think this is related to the issue. I went and read the relearn procedure from my '98' manual, but, other than describing 'crank speed variation', it didn't mention any symptoms such as always-on injectors.
Still, because the code isn't erased, it seems a good place to start.
I'm wondering if a noid lamp would reflect the trouble by showing an 'always-on' LED, or an LED which does more than just flash (as it would normally)?
I will try to find somebody local to me that can take a look at the ecm. I cant find any answers to this problem doing the normal searches. I thought somebody here could figure this out. its probably something simple lol...
0 psi at the fuel gage. Do to If i connect the pump positive to the battery for more than a split second it will kill the engine. "IT IS GETTING TO MUCH FUEL THROUGH THE INJECTORS" some how. I cant leave the fuel pump connected to the power at all, Soon as it builds any pressure at all it will flood and die?
I know it sounds backwards but this is whats its is doing???????????????
I am puzzled as well.
I am going to check all my grounds today.
Last edited by IntercooledC6; Sep 18, 2011 at 09:59 AM.
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Not to belabor the point...a noid lamp from Autozone/Advance Auto could tell you whether the injectors are 'on' too long, and whether they're cycling properly. This could eliminate the pump & regulator as a cause.
The noid is a 'free' rental.
The noid is a 'free' rental.
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Believe it or not, but I just keep increasing the fuel pressure. At first it would not run with any fuel pressure at all. As soon as the gauge needle jumped up to 1 psi it would kill the motor. I think the PCM thought it was at high rpm? The more it ran the better it ran. It relearned and trimmed the fuel.
When I get time I will post more. At work now lol..
When I get time I will post more. At work now lol..
might get a scanner and monitor it for a bit.. but yeah.. sounds like the relearn has resolved most of not all of your noted problems.. get it out on the streets and highways to complete the relearn. I think there were threads on who to do a relearn correctly.
Good Luck.
Good Luck.
Last edited by bczee; Sep 19, 2011 at 03:26 PM.
