70whp LS1 swap
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70whp LS1 swap I recently did an LS1 swap into a tube frame chassis. The motor and wiring harness are from a 2004 GTO.
The motor has a LS2 intake manifold and injectors.
I'm running 1 5/8" sanderson blockhugger headers - temporarily open with no exhaust.
In hptuners, I tried setting the injector scaling to 32lbs/min, but it didn't really help much.
I have 58psi of fuel pressure at the rail.
If I go WOT with a MAF, the car chokes and dies. I tried replacing the MAF, but got the same result. If I unplug it and run MAP only, it runs smoother.
The car idles and drives just fine, but it's horrendously slow. I took a 1st gear WOT log and it made about 70hp. I don't yet know my AFRs (since I don't yet have an exhaust), but I'm working on that.
I feel like for it to be this slow, I must be missing something minor which is causing a major issue. Any ideas? See attached log.
The motor has a LS2 intake manifold and injectors.
I'm running 1 5/8" sanderson blockhugger headers - temporarily open with no exhaust.
In hptuners, I tried setting the injector scaling to 32lbs/min, but it didn't really help much.
I have 58psi of fuel pressure at the rail.
If I go WOT with a MAF, the car chokes and dies. I tried replacing the MAF, but got the same result. If I unplug it and run MAP only, it runs smoother.
The car idles and drives just fine, but it's horrendously slow. I took a 1st gear WOT log and it made about 70hp. I don't yet know my AFRs (since I don't yet have an exhaust), but I'm working on that.
I feel like for it to be this slow, I must be missing something minor which is causing a major issue. Any ideas? See attached log.
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I do realize it's a downgrade, but it's what the motor came with. I plan on eventually upgrading it to a FAST 92.
There are no O2 sensors on the car.
I disabled VATS to get it running.
Could it be running in limp mode somehow? If so, how could I check?
There are no O2 sensors on the car.
I disabled VATS to get it running.
Could it be running in limp mode somehow? If so, how could I check?
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Teching In
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But I do plan on running O2s once the exhaust is complete
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Teching In
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Stupid question - if this ECU and harness came out of an automatic by some chance, would it put it in a limp mode? I did flash it to a manual just in case, but perhaps if it's an auto ECU then it can't be converted? Just reaching here.
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No, if you changed it to manual trans then its good.
Its almost undoubtedly in the tune. You need to turn off fuel trims and set the temps for closed loop really high so it won't attempt closed loop. Might as well turn off the codes for O2 sensors until you get some. Its not likely going to run very well until you either get oxygen sensors in there or disable them completely and run open loop speed density without them.
Its almost undoubtedly in the tune. You need to turn off fuel trims and set the temps for closed loop really high so it won't attempt closed loop. Might as well turn off the codes for O2 sensors until you get some. Its not likely going to run very well until you either get oxygen sensors in there or disable them completely and run open loop speed density without them.
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Well, I've started making an exhaust for it now. I'll probably just get the first foot or so of it welded up and weld some O2 bungs in it. After that I'll disable the rear O2s and give it a whirl. Anything else I should disable? The car has no AC and no PS.
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Ok, I disabled all of those settings. Some of them weren't "disable-able" so I zeroed them out, etc. I also disabled the associated CELs.
But I think I figured out the issue.
Today, I completed my downpipes for the car, and welded in O2 bungs. I put two bungs in the driver's side downpipe so that way I could install a wideband.
I started the car, and to my dismay the wideband read 20.9:1 AFR. I knew this had to be wrong, because the engine wouldn't run if it were that lean. I calibrated the gauge (one I've used before for tuning) and nothing changed.
After letting it run for a few minues i decided to check the temp of the headers to make sure they were running at the proper temp. The passenger side were very hot and the driver's side were just warm.
I scanned the computer for codes. The important one was a P0200 - injector circuit.
Turns out that when the car wouldn't start last week and we found that there we found a red wire that powered the injectors, we failed to realize that it was only powering one bank. There is a green wire that powers the bank on the driver's side.
I powered that green wire, cleared the CELs, and Voila! Running on all 8.
Still runs like **** with the MAF plugged in, though.
TL;DR - Car was making no power because I was running on 4cyl due to the green injector power wire having no juice.
But I think I figured out the issue.
Today, I completed my downpipes for the car, and welded in O2 bungs. I put two bungs in the driver's side downpipe so that way I could install a wideband.
I started the car, and to my dismay the wideband read 20.9:1 AFR. I knew this had to be wrong, because the engine wouldn't run if it were that lean. I calibrated the gauge (one I've used before for tuning) and nothing changed.
After letting it run for a few minues i decided to check the temp of the headers to make sure they were running at the proper temp. The passenger side were very hot and the driver's side were just warm.
I scanned the computer for codes. The important one was a P0200 - injector circuit.
Turns out that when the car wouldn't start last week and we found that there we found a red wire that powered the injectors, we failed to realize that it was only powering one bank. There is a green wire that powers the bank on the driver's side.
I powered that green wire, cleared the CELs, and Voila! Running on all 8.
Still runs like **** with the MAF plugged in, though.
TL;DR - Car was making no power because I was running on 4cyl due to the green injector power wire having no juice.
