Start up tune advice
Start up tune advice Just tried starting my lq4/t56 swapped 240sx and it cranked good then stopped cranking all together. I did not try to turn the key again to see if it would crank again cause it's obvious there's an issue. Maybe there's something off in the tune to where it's flooding the motor and hydrolocking for example. Just put the HPtuners on it and I am not real familiar with the software (had a V1 AEM stand alone before). Car has a cam, ls6 intake, 80Lb injectors, and turbo. If you could take a look at the tune any suggestions would be appreciated.
Won't crank as in starter does not turn motor, or won't crank as in motor turns but won't fire? Sounds dumb to ask, but you'd be amazed how often those are used interchangeably. I notice you have your maf set to fail, but the codes disabled, so the maf can't fail. You need to set the maf to set a code on first error even on SD OS. Change VATS from "Serial" to "not Fitted". Lowest cell in maf curve, set to 20 g/s to get fuel until the maf fails.
Won't crank as in starter does not turn motor, or won't crank as in motor turns but won't fire? Sounds dumb to ask, but you'd be amazed how often those are used interchangeably. I notice you have your maf set to fail, but the codes disabled, so the maf can't fail. You need to set the maf to set a code on first error even on SD OS. Change VATS from "Serial" to "not Fitted". Lowest cell in maf curve, set to 20 g/s to get fuel until the maf fails.
Yes. The ECU needs to set the maf code. You can leave the SES box unchecked, but set it to MIL on first error in the menu option. Set your lowest (usually 1500 Hz) cell to 20 g/s so it gets air until the maf fails. Good news is, it likely didn't flood
Launching!
Joined: Jan 2018
Posts: 283
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that file needs an awful lot of work.
also need to know the combo in detail, fuel system type, map sensor, IAT sensor set up etc etc.
luke@dieseltech.com.au
also need to know the combo in detail, fuel system type, map sensor, IAT sensor set up etc etc.
luke@dieseltech.com.au
So I figured out I have to do some diagnosing with the starter circuit first. I noticed the negative cable at the battery was pretty hot after only about 5 seconds of cranking. Not sure what's going on. I have battery positive ran straight to the starter. I have battery negative ran straight to a starter bolt. Then I have a negative off the battery going to the chassis. And I have a negative from the other starter bolt to the chassis. And I have a negative off one head to the chassis. Not sure what's going on unless the starter itself can cause the hot negative cable.
that file needs an awful lot of work.
also need to know the combo in detail, fuel system type, map sensor, IAT sensor set up etc etc.
luke@dieseltech.com.au
also need to know the combo in detail, fuel system type, map sensor, IAT sensor set up etc etc.
luke@dieseltech.com.au
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Launching!
Joined: Jan 2018
Posts: 283
Likes: 0
So I figured out I have to do some diagnosing with the starter circuit first. I noticed the negative cable at the battery was pretty hot after only about 5 seconds of cranking. Not sure what's going on. I have battery positive ran straight to the starter. I have battery negative ran straight to a starter bolt. Then I have a negative off the battery going to the chassis. And I have a negative from the other starter bolt to the chassis. And I have a negative off one head to the chassis. Not sure what's going on unless the starter itself can cause the hot negative cable.
the way you have it has a dead short over starter when the real pulls and sends current to the windings. The current is literally going through the windings to body of the starter to your battery connected ground.
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Verdad Gallardo why do U have a battery negative running to a starter bolt? You should have battery positive ran to the starter only. The starter should be independently earthed to the chassis or to the engine if the engine has an earth strap to chassis. The battery negative should also be independently ground.
the way you have it has a dead short over starter when the real pulls and sends current to the windings. The current is literally going through the windings to body of the starter to your battery connected ground.
Launching!
Joined: Jan 2018
Posts: 283
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I have battery negative ran to the starter mounting bolt. The starter still has the engine ground also since I have a ground wire from the engine to chassis. And the starter has a negative from the other mounting bolt to the chassis. I've seen lots of people run battery negative to a starter mounting bolt and I figured that's best so it has as little path as possible for the starting circuit.
i would let the starter earth to the engine alone. Independently ground the engine and battery to the. Chassis. Remove the wire from starter body to battery,
starter earths through body and there is no earth post on these like there is on HD starters. You’ve given the starter body a direct path back to the battery. Is draws big amps that current flow will get the negative nice and warm.
i would let the starter earth to the engine alone. Independently ground the engine and battery to the. Chassis. Remove the wire from starter body to battery,
Did as you said and the car fired up immediately. It died almost instantly but there's a few things I need to do under the hood before I go any further. I appreciate your help. Will add to this thread if needed once I get the other things taken care of. Thanks again!
Any idea what this means? I realized that I had not actually saved the tune (explains why it died since it has a stock 5.3 tune loaded) to the cars computer, just modified it for the future. Tried loading the tune into it and it came up with this message.
Well it won't attach my picture for some reason. It pops up with a message that reads "File OS ID does not match VCM OS ID. File OS1261005 VCM OS 9381344. Please load a file that is compatible with this VCM."
Edit again: Figured out why it was popping up with that message^. I had to click write entire. Now the car won't start again though. Different no start now though. Like it tries to start for a second but wwon't. Currently loaded tune is attached.
Well it won't attach my picture for some reason. It pops up with a message that reads "File OS ID does not match VCM OS ID. File OS1261005 VCM OS 9381344. Please load a file that is compatible with this VCM."
Edit again: Figured out why it was popping up with that message^. I had to click write entire. Now the car won't start again though. Different no start now though. Like it tries to start for a second but wwon't. Currently loaded tune is attached.
Last edited by partemisio; Sep 8, 2018 at 06:17 PM.