Need Help, Swap fires but doesn't idle
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Need Help, Swap fires but doesn't idle
Ok, well I thought I had made it into the clear but I guess not. Here's the deal. I have a 97 Nissan 240sx that I swapped in a 2005 L33 with a T56 set up DBW. My engine harness is from a 2004 Silverado 1500 and so is my Tac, Pedal and PCM, but not the same truck.
I've almosted finished my swap, but here are my issues. When I turn the key to run the Throttle plate opens and shuts and the fuel pump primes. I fire the engine and it revs up to around 2000 Rpms sometimes 2500and then it drops to about a 1000 or so for a second or two. Then she shuts off. I have no response at all from the gas pedal and everytime I try to restart her she does the same.
I hooked up a OBD2 scanner and it reads no codes at all. I don't know where to start.
I thought it was my altenator wire not being connected, because I read somewhere that the PCM has to detect that the system is charging or it would send the PCM into Limp mode. But I finally removed pins A and C from the wire and plugged it in and theres no change.
I've almosted finished my swap, but here are my issues. When I turn the key to run the Throttle plate opens and shuts and the fuel pump primes. I fire the engine and it revs up to around 2000 Rpms sometimes 2500and then it drops to about a 1000 or so for a second or two. Then she shuts off. I have no response at all from the gas pedal and everytime I try to restart her she does the same.
I hooked up a OBD2 scanner and it reads no codes at all. I don't know where to start.
I thought it was my altenator wire not being connected, because I read somewhere that the PCM has to detect that the system is charging or it would send the PCM into Limp mode. But I finally removed pins A and C from the wire and plugged it in and theres no change.
#3
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Do you have the MAF installed? I would also double check that your pedal, tac module, pcm, and TB are all compatible parts. I've had a junkyard 6.0 come with a pcm that said it was a 4.8l yukon in the VIN.
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I had another member here on the forums reflash my PCM and he removed the VAT's and all emissions. I don't have a MAF.
How would I check the parts for compatability? I bought my PCM, pedal anf Tac from the same junkyard. The sent me the PCM and pedal together and forgot the pedal and harness. I had to call back and the claimed they pulled the tac moduel and harness from the samr truck like I had initially requested, but as far as I know I really have no way of verifying.
How would I check the parts for compatability? I bought my PCM, pedal anf Tac from the same junkyard. The sent me the PCM and pedal together and forgot the pedal and harness. I had to call back and the claimed they pulled the tac moduel and harness from the samr truck like I had initially requested, but as far as I know I really have no way of verifying.
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It's because you don't have a maf in there. The truck pcm uses mass airflow as a sanity check for the electonic throttle. You need to have a couple of codes deleted and tables altered to keep the pcm from killing the throttle on you. Or you could just put a maf on there and it will work like a charm.
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I guess I will need to check with him to see if the tables were altered when the MAF was deleted or not. Maybe I'm just confused and I should have a MAF.
Well, would the pedal respond with the key in the Run position or does the pedal only respond when the engine is running.
If the MAF wasn't deleted from my PCM shouldn't I be throwing a MAF code or something? My PCM is not throwing any codes.
Well, would the pedal respond with the key in the Run position or does the pedal only respond when the engine is running.
If the MAF wasn't deleted from my PCM shouldn't I be throwing a MAF code or something? My PCM is not throwing any codes.
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Is there anyone to remove the PCM from REP mode so that I can verify that the pedal is actually working without buying a MAF and rewiring my harness for 1?
Also, I spoke to the member that did my tune and he said that he did remove the MAF error reporting, but he's not sure how that would affect the DBW pedal operation. He's done it many times on DBC setup's but there wasn't any info out there that he could find on how it operates in the DBW setup.
I guess I might just have to buy a MAF and find out.
Also, I spoke to the member that did my tune and he said that he did remove the MAF error reporting, but he's not sure how that would affect the DBW pedal operation. He's done it many times on DBC setup's but there wasn't any info out there that he could find on how it operates in the DBW setup.
I guess I might just have to buy a MAF and find out.
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Or is there anyone to verify that the PCM is actually in REP mode? Like I said before I've tried to pull the codes, but there are none. I assume that is because the error reporting for the MAF was removed.
Sorry, I'm just trying to isolate the problem the best I can, so I'm just not out spending money trouble shooting when I'm already about $1000 over budget. Thanks guys.
Sorry, I'm just trying to isolate the problem the best I can, so I'm just not out spending money trouble shooting when I'm already about $1000 over budget. Thanks guys.
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Ask your tuner if he set the p1514 dtc to "no error reported" and maxed out the calculated airflow p1514 table. I think that is what finally did the trick for me on the one of these I ran into.
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Ok, I'm still trying to figure out if I have an issue with my TAC as well, because it doesn't seem to respond with the key is in the RUN position as well. I called a local junkyard and they have a MAF I can pickup on my lunch break for $25, which an't bad.
Is it safe to assume that since the PCM is not throwing a code for the TAC like U0107 (Communication with TAC lost) that I don't have an issue with the pedal? Sorry, I'm just a little worried that the junkyard that shipped me the pedal, PCM and TAC lied and the TAC and Pedal were not from the same truck as the PCM and are not compatiable.
Is it safe to assume that since the PCM is not throwing a code for the TAC like U0107 (Communication with TAC lost) that I don't have an issue with the pedal? Sorry, I'm just a little worried that the junkyard that shipped me the pedal, PCM and TAC lied and the TAC and Pedal were not from the same truck as the PCM and are not compatiable.
#14
i had the same problem on my 67 mustang. it turned out i was not getting true 12 volts to the pcm. check with mulimeter not test lite. every wire under the dash would drop below 12volts when starter engauged. i ended up running a seperate wire and installing a toggle type switch for the timebeing.
#15
Do truck motors not have VATS? Is that why no one is agreeing with me? Most of the time with ls1s the VATS is what people overlook and they go around checking everything just to find out they just need to disable it
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Ok, I'm still trying to figure out if I have an issue with my TAC as well, because it doesn't seem to respond with the key is in the RUN position as well. I called a local junkyard and they have a MAF I can pickup on my lunch break for $25, which an't bad.
Is it safe to assume that since the PCM is not throwing a code for the TAC like U0107 (Communication with TAC lost) that I don't have an issue with the pedal? Sorry, I'm just a little worried that the junkyard that shipped me the pedal, PCM and TAC lied and the TAC and Pedal were not from the same truck as the PCM and are not compatiable.
Is it safe to assume that since the PCM is not throwing a code for the TAC like U0107 (Communication with TAC lost) that I don't have an issue with the pedal? Sorry, I'm just a little worried that the junkyard that shipped me the pedal, PCM and TAC lied and the TAC and Pedal were not from the same truck as the PCM and are not compatiable.
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The battery voltage has much to do with it...ask me how I know
If your alternator is not producing or hooked up incorrectly, your pedal won't work. I diagnosed for hours before finally hooking up my alt and belt...problem resolved.
If your alternator is not producing or hooked up incorrectly, your pedal won't work. I diagnosed for hours before finally hooking up my alt and belt...problem resolved.