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Old 06-06-2018, 02:49 PM   #11
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Fuel injectors are obviously more work to get running correctly. Knowing when the spray nozzles are getting clogged and not spraying uniform is always guess work.

A carburetor might not make the same power as a peak running injector, but it can make more power than injectors that are gummed up.

High tech just requires more maintenance.
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Old 06-08-2018, 05:05 AM   #12
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I haven't switched to the carb setup yet, but just wanted to add that this motor acts like it has either a rev limiter on it, or it's in limp mode.
It runs great at idle, even up to around 1800 rpms... But try to go over that, driving or not, and it immediately begins popping and losing all power... Go back down to 1800, it runs fine... Weird.
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Old 06-08-2018, 05:22 AM   #13
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Originally Posted by Deerhurst View Post
I don't understand why people say carbs make more power. They don't. Its just physics and engine design. They are also far more fuss than EFI. Volumetric efficiency is pretty important and its not very good on a carbed motor but fantastic on direct injection. The closer to direct injection the better.
They do, and in my case it certainly does, if done right. I've got the old z24 and I've got approx 150 hp, mostly due to lots of work, light modified engine and, 32/36 weber.
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Old 06-08-2018, 05:55 AM   #14
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They just don't. I've done all the design math and the same engine with a carb always makes less power. No way around it. Volumetric efficiency just isn't there. You are displacing air with fuel which hurts your power. I guarantee you all things equal a TBI unit will make a measurable bit more power. It will depend on the motor, of course, but you would be able to see it on a dyno. Better the volumetric efficiency the more power you can make. One of the reasons the HP numbers went up on the VG30 going from TBI to MPFI. With fuel injection its just so much easier to stay closer to perfect stoichiometric A/F ratios and compensate for the environment not to mention fuel atomization and mixing consistency. The mixture heater is there to help this too.



Not to mention seasonal tuning, elevation tuning ,etc. At that point set it up for a carb and get a stand alone EFI setup to replace that carb. There is a reason nobody but NASCAR and die hard carb people use carbs.
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Old 06-08-2018, 06:44 AM   #15
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Originally Posted by Deerhurst View Post
They just don't. I've done all the design math and the same engine with a carb always makes less power. No way around it. Volumetric efficiency just isn't there. You are displacing air with fuel which hurts your power. I guarantee you all things equal a TBI unit will make a measurable bit more power. It will depend on the motor, of course, but you would be able to see it on a dyno. Better the volumetric efficiency the more power you can make. One of the reasons the HP numbers went up on the VG30 going from TBI to MPFI. With fuel injection its just so much easier to stay closer to perfect stoichiometric A/F ratios and compensate for the environment not to mention fuel atomization and mixing consistency. The mixture heater is there to help this too.



Not to mention seasonal tuning, elevation tuning ,etc. At that point set it up for a carb and get a stand alone EFI setup to replace that carb. There is a reason nobody but NASCAR and die hard carb people use carbs.
well, im gonna have to let you label me a 'die hard carb person' and leave it at that.
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Old 06-08-2018, 07:07 AM   #16
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I just want my truck to run.
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Old 06-08-2018, 01:42 PM   #17
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Originally Posted by bwilson27 View Post
I just want my truck to run.
Hi Mr. Wilson.....
Have you checked your connections to the injectors? I had a similar problem to your description, and I was searching for answers to my code 51 and found this thread http://www.infamousnissan.com/forum/...ad.php?t=25332

I split my harness where it exits the firewall and runs to the intake and found the two culprit connectors, the one injector wire completely corroded through and the other was not much better, here is what I found:




The wiring was badly corroded and broke off by just moving the harness around, for both the white red and the black red that feeds the injectors. I trimmed back the wires to expose fresh copper, soldered and heat shrunk the connections and the problem was corrected.
After reading the above attached post it became obvious to me that this problem needed to be fixed because somewhere it was mentioned that this was a TSB at Nissan at some point, even if this wasn't the cause of my own stuttering problem.
I hope this helps.
Let us know what you find.
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Old 06-08-2018, 03:13 PM   #18
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Quote:
Originally Posted by bwilson27 View Post
I haven't switched to the carb setup yet, but just wanted to add that this motor acts like it has either a rev limiter on it, or it's in limp mode.
It runs great at idle, even up to around 1800 rpms... But try to go over that, driving or not, and it immediately begins popping and losing all power... Go back down to 1800, it runs fine... Weird.
Are you SURE your ECU doesn't show a code (other than 55)? It acts like it's in Limp Mode - an ECU condition.

Quote:
Originally Posted by 86.5KC View Post
The wiring was badly corroded and broke off by just moving the harness around, for both the white red and the black red that feeds the injectors. I trimmed back the wires to expose fresh copper, soldered and heat shrunk the connections and the problem was corrected.
After reading the above attached post it became obvious to me that this problem needed to be fixed because somewhere it was mentioned that this was a TSB at Nissan at some point, even if this wasn't the cause of my own stuttering problem.
We've got a thread on here that may be exactly what you are describing.

Is this it?

FIX: erratic idle, low speed driveability, possibly more
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Old 06-08-2018, 03:43 PM   #19
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Originally Posted by jp2code View Post
Are you SURE your ECU doesn't show a code (other than 55)? It acts like it's in Limp Mode - an ECU condition.



I'll check it again today. I wasn't sure if Limp Mode was even a possibility with this ecu.
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Old 06-08-2018, 03:47 PM   #20
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Quote:
Originally Posted by 86.5KC View Post
Hi Mr. Wilson.....
Have you checked your connections to the injectors?
Yes I have, but I haven't unwrapped to the thicker harness that goes into the firewall... I've gotten to maybe 8 inches away from it (the firewall), and the wiring looks good. Like I mentioned, the connection to the MAF was bad and I replaced it, making the engine run much smoother, but with that bog at 1800 RPMS.
All the other wiring looks good.
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