5.3 swap woes
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Teching In
Joined: Jul 2010
Posts: 23
Likes: 1
5.3 swap woes Problem = Engine only running on passenger side cylinders. Hesitating, popping, and banging from the exhaust when I move the throttle.
Swap vehicle = 2000 Jeep TJ (with a 05 jeep return-less fuel pump that’s rated at 58psi with a regulator inside the tank).
Engine = 03 Silverado 5.3, ls1 intake, aftermarket fuel rails, and flex fuel injectors. All cylinders have spark.
Transmission = Manual
Thoughts of what may be wrong =
1. The Silverado had the drive by wire box with a cable to the TB under the hood. When I had VATS and Emissions deleted I had the ecu programed to drive by cable so I could ditch the box/cable setup (one less thing to go wrong is my reasoning).. I’m not sure if I have the correct TB or things wired correctly for this.
2. I have a fuel pressure gauge on the rail reading 55psi.... does the engine need more psi?
3. I did my own engine harness and I screwed something up.
4. A sensor has failed... crank, cam or ???
5. The ecu tuner did something that requires a different reluctor wheel.
6. It’s a blue / red harness so maybe my engine is a 2002 and I told the ecu guy 2003 which may have screwed something up, confused reluctor wheels?
Any help is appreciated... this is a 2 year long project I was hoping to have on the road by spring yet it sits in my shop. I’ll do my best to test and answer questions.
Swap vehicle = 2000 Jeep TJ (with a 05 jeep return-less fuel pump that’s rated at 58psi with a regulator inside the tank).
Engine = 03 Silverado 5.3, ls1 intake, aftermarket fuel rails, and flex fuel injectors. All cylinders have spark.
Transmission = Manual
Thoughts of what may be wrong =
1. The Silverado had the drive by wire box with a cable to the TB under the hood. When I had VATS and Emissions deleted I had the ecu programed to drive by cable so I could ditch the box/cable setup (one less thing to go wrong is my reasoning).. I’m not sure if I have the correct TB or things wired correctly for this.
2. I have a fuel pressure gauge on the rail reading 55psi.... does the engine need more psi?
3. I did my own engine harness and I screwed something up.
4. A sensor has failed... crank, cam or ???
5. The ecu tuner did something that requires a different reluctor wheel.
6. It’s a blue / red harness so maybe my engine is a 2002 and I told the ecu guy 2003 which may have screwed something up, confused reluctor wheels?
Any help is appreciated... this is a 2 year long project I was hoping to have on the road by spring yet it sits in my shop. I’ll do my best to test and answer questions.
Launching!
Joined: Aug 2015
Posts: 206
Likes: 11
From: Duvall, WA
How have you determined that the engine is only running on the passenger's side cylinders? You've confirmed that all cylinders have spark, yes, but do they have fuel? If you hook up an OBDII scanner, can you pull any trouble codes off the ECU? For example, have you lost an O2 sensor on one bank?
Things to consider, many of which are going to require some kind of data from the ECU to confirm:
1. Are you getting reasonable signals from the MAF and MAP sensors? What about IAT and coolant temps (since these will affect commanded timing advance)?
2. Are you getting signals from both O2 sensors? What do the fuel trims look like? Are they similar from bank to bank?
3. Are you getting a throttle position signal? This probably doesn't matter as much, but it might affect transient behavior.
4. Have reasonable values for the fuel injectors been plugged into the ECU?
5. You say that all cylinders have spark, but are you really sure that both of the coil harnesses have a good path to ground (preferably grounded to the nearest cylinder head)? These engines run very badly if you don't have good ignition grounds for both racks of coils.
6. Have you confirmed that the injectors are receiving an electrical signal?
With regard to your specific questions:
1. Data from the ECU regarding TPS signal, plus verifying that the ECU does something with the idle air controller would probably help confirm that.
2. I'd think 55 psi should be plenty, at least for the purposes of this discussion.
3. Maybe? Good grounds everywhere, especially for the coils? No breaks in O2 sensor wiring or injector wiring?
4. I suppose anything is possible.
5/6. I think trucks retained 24x/1x through around 2005. I doubt you'd even be able to start the engine if the ECU was expecting a 58x/4x signal, and I don't think it is possible to program the older ECUs to recognize the newer reluctor patterns anyway.
Things to consider, many of which are going to require some kind of data from the ECU to confirm:
1. Are you getting reasonable signals from the MAF and MAP sensors? What about IAT and coolant temps (since these will affect commanded timing advance)?
2. Are you getting signals from both O2 sensors? What do the fuel trims look like? Are they similar from bank to bank?
3. Are you getting a throttle position signal? This probably doesn't matter as much, but it might affect transient behavior.
4. Have reasonable values for the fuel injectors been plugged into the ECU?
5. You say that all cylinders have spark, but are you really sure that both of the coil harnesses have a good path to ground (preferably grounded to the nearest cylinder head)? These engines run very badly if you don't have good ignition grounds for both racks of coils.
6. Have you confirmed that the injectors are receiving an electrical signal?
With regard to your specific questions:
1. Data from the ECU regarding TPS signal, plus verifying that the ECU does something with the idle air controller would probably help confirm that.
2. I'd think 55 psi should be plenty, at least for the purposes of this discussion.
3. Maybe? Good grounds everywhere, especially for the coils? No breaks in O2 sensor wiring or injector wiring?
4. I suppose anything is possible.
5/6. I think trucks retained 24x/1x through around 2005. I doubt you'd even be able to start the engine if the ECU was expecting a 58x/4x signal, and I don't think it is possible to program the older ECUs to recognize the newer reluctor patterns anyway.
Thread Starter
Teching In
Joined: Jul 2010
Posts: 23
Likes: 1
Thread Starter
Teching In
Joined: Jul 2010
Posts: 23
Likes: 1
How have you determined that the engine is only running on the passenger's side cylinders?
I held my hand on the drivers side headers and they are basically cold. The passenger side are too hot to touch.
You've confirmed that all cylinders have spark, yes, but do they have fuel? If you hook up an OBDII scanner, can you pull any trouble codes off the ECU? For example, have you lost an O2 sensor on one bank?
I haven't hooked up my OBDII port yet.... I guess I should have done this first. I will work on this.
Things to consider, many of which are going to require some kind of data from the ECU to confirm:
1. Are you getting reasonable signals from the MAF and MAP sensors? What about IAT and coolant temps (since these will affect commanded timing advance)?
2. Are you getting signals from both O2 sensors? What do the fuel trims look like? Are they similar from bank to bank?
3. Are you getting a throttle position signal? This probably doesn't matter as much, but it might affect transient behavior.
4. Have reasonable values for the fuel injectors been plugged into the ECU?
I'll check when I get the OBDII hooked up.
5. You say that all cylinders have spark, but are you really sure that both of the coil harnesses have a good path to ground (preferably grounded to the nearest cylinder head)? These engines run very badly if you don't have good ignition grounds for both racks of coils.
I'll double check this.
6. Have you confirmed that the injectors are receiving an electrical signal?
I'm purchasing a Noid light and will check.
With regard to your specific questions:
1. Data from the ECU regarding TPS signal, plus verifying that the ECU does something with the idle air controller would probably help confirm that.
2. I'd think 55 psi should be plenty, at least for the purposes of this discussion.
3. Maybe? Good grounds everywhere, especially for the coils? No breaks in O2 sensor wiring or injector wiring?
4. I suppose anything is possible.
Thanks... will check.
5/6. I think trucks retained 24x/1x through around 2005. I doubt you'd even be able to start the engine if the ECU was expecting a 58x/4x signal, and I don't think it is possible to program the older ECUs to recognize the newer reluctor patterns anyway.
I guess that rules out my idea of the ecu being programmed for the wrong reluctor.
Looks like I have some work to do. Thanks for the ideas.
I held my hand on the drivers side headers and they are basically cold. The passenger side are too hot to touch.
You've confirmed that all cylinders have spark, yes, but do they have fuel? If you hook up an OBDII scanner, can you pull any trouble codes off the ECU? For example, have you lost an O2 sensor on one bank?
I haven't hooked up my OBDII port yet.... I guess I should have done this first. I will work on this.
Things to consider, many of which are going to require some kind of data from the ECU to confirm:
1. Are you getting reasonable signals from the MAF and MAP sensors? What about IAT and coolant temps (since these will affect commanded timing advance)?
2. Are you getting signals from both O2 sensors? What do the fuel trims look like? Are they similar from bank to bank?
3. Are you getting a throttle position signal? This probably doesn't matter as much, but it might affect transient behavior.
4. Have reasonable values for the fuel injectors been plugged into the ECU?
I'll check when I get the OBDII hooked up.
5. You say that all cylinders have spark, but are you really sure that both of the coil harnesses have a good path to ground (preferably grounded to the nearest cylinder head)? These engines run very badly if you don't have good ignition grounds for both racks of coils.
I'll double check this.
6. Have you confirmed that the injectors are receiving an electrical signal?
I'm purchasing a Noid light and will check.
With regard to your specific questions:
1. Data from the ECU regarding TPS signal, plus verifying that the ECU does something with the idle air controller would probably help confirm that.
2. I'd think 55 psi should be plenty, at least for the purposes of this discussion.
3. Maybe? Good grounds everywhere, especially for the coils? No breaks in O2 sensor wiring or injector wiring?
4. I suppose anything is possible.
Thanks... will check.
5/6. I think trucks retained 24x/1x through around 2005. I doubt you'd even be able to start the engine if the ECU was expecting a 58x/4x signal, and I don't think it is possible to program the older ECUs to recognize the newer reluctor patterns anyway.
I guess that rules out my idea of the ecu being programmed for the wrong reluctor.
Looks like I have some work to do. Thanks for the ideas.
Last edited by powerplant9; May 30, 2019 at 11:02 AM. Reason: entered wrong info
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TECH Regular
Joined: Dec 2011
Posts: 420
Likes: 115
If those tips don't work, also verify that your injectors are opening. You'll need to pull them, and then you can test them by putting a 9v battery across the injectors.
I just had a similar situation, swapping over to a new intake manifold.. one I took from a TBSS motor that had been sitting for 5 years on my shelf. Every injector on the drivers side was opening fine, every injector on the passenger side was stuck shut.
Now, if you are getting raw gas smell from the exhaust, or wet spark plugs, then you are likely getting fuel.
Do you have any spare injectors laying around, that you can unplug one of the drivers side injectors, and plug in a spare thats not connected to the rail? Thats another way to verify wiring.
I just had a similar situation, swapping over to a new intake manifold.. one I took from a TBSS motor that had been sitting for 5 years on my shelf. Every injector on the drivers side was opening fine, every injector on the passenger side was stuck shut.
Now, if you are getting raw gas smell from the exhaust, or wet spark plugs, then you are likely getting fuel.
Do you have any spare injectors laying around, that you can unplug one of the drivers side injectors, and plug in a spare thats not connected to the rail? Thats another way to verify wiring.
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Verdad Gallardo Thread Starter
Teching In
Joined: Jul 2010
Posts: 23
Likes: 1
If those tips don't work, also verify that your injectors are opening. You'll need to pull them, and then you can test them by putting a 9v battery across the injectors.
I just had a similar situation, swapping over to a new intake manifold.. one I took from a TBSS motor that had been sitting for 5 years on my shelf. Every injector on the drivers side was opening fine, every injector on the passenger side was stuck shut.
Now, if you are getting raw gas smell from the exhaust, or wet spark plugs, then you are likely getting fuel.
Do you have any spare injectors laying around, that you can unplug one of the drivers side injectors, and plug in a spare thats not connected to the rail? Thats another way to verify wiring.
I just had a similar situation, swapping over to a new intake manifold.. one I took from a TBSS motor that had been sitting for 5 years on my shelf. Every injector on the drivers side was opening fine, every injector on the passenger side was stuck shut.
Now, if you are getting raw gas smell from the exhaust, or wet spark plugs, then you are likely getting fuel.
Do you have any spare injectors laying around, that you can unplug one of the drivers side injectors, and plug in a spare thats not connected to the rail? Thats another way to verify wiring.
They are all brand new injectors but you never know I guess.
Launching!
Joined: Aug 2015
Posts: 206
Likes: 11
From: Duvall, WA
FYI, when I've tried unplugging fuel injectors on a running LS engine with a P59 ECU, it actually logged codes for open circuits on the injectors. So there's some interesting stuff there.
Based on my own experience, I'm sort of betting that one of your coil racks has a crappy ground, though.
Based on my own experience, I'm sort of betting that one of your coil racks has a crappy ground, though.