First, I like to apologize in advance, I'm new to posting in forums so if there is any conduct or etiquette that I didn't follow please forgive me.
I recently rebuilt my VG30DE from the ground up and excluding the headers I installed, it's completely stock. I had my heads and valves rebuilt as well and I have new pistons, piston rings, and injectors. Let it be known that this was my first time rebuilding an engine but I was extremely careful with labeling and taking pictures. My car is a 1990 N/A engine.
Now it starts up but idles rough and I've got white/gray smoke coming out of the exhaust. The longest I've had it running constantly was about 5 minutes but my father helped me do this project and from his experience, he said it's normal to have that smoke out of the exhaust for a while. All of this is to just give a little insight as to what I'm looking at.
The big issue I'm having right now is that if i try and touch the gas, it starts to sputter out and die. According to my father who was standing behind the car when I touched the throttle, it started to kick out what he and I both believe to be fuel and I will further say that I can smell fuel as if it was running rich.
So all in all, I need help trying to figure this one out. CAS is the same, MAF is new, PTU is new, and the IAC Valve is new.
Could the CAS cause something like this? Or is it a problem with the injectors or even the timing?
Thank you,
Smiley
Rebuilt N/A motor, rough idle.
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Smileysauce
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- Car: 1990 300ZX Z32 N/A
- Location: Tulsa OK
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Ken@PTUNING
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Re: Rebuilt N/A motor, rough idle.
Make sure that the engine is in time correctly. If you're off by a tooth, the engine could run extremely rough. You could check to make sure the engine is sparking at the correct time with a timing light if you want to see if the CAS could be a contributing factor.
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Smileysauce
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- Location: Tulsa OK
Re: Rebuilt N/A motor, rough idle.
Okay, thank you Ken. I will definitely double check my timing and CAS.
If I may ask another question, It has been brought to my attention that if I mistakenly got the incorrect output injectors I could experience symptoms like what I've currently got due to the ECU being tuned for only one set output. (i.e. 370cc injectors instead of 270cc) Is that also a possibility or am I mistaken?
If I may ask another question, It has been brought to my attention that if I mistakenly got the incorrect output injectors I could experience symptoms like what I've currently got due to the ECU being tuned for only one set output. (i.e. 370cc injectors instead of 270cc) Is that also a possibility or am I mistaken?
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Ken@PTUNING
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Re: Rebuilt N/A motor, rough idle.
Yes, that is also a possibility. However, a 370cc injector running a car tuned to run on 270cc injectors should only be running 37% richer than normal. Most ECU's will be able to trim fuel well enough to run correctly as their range is about +/-20-25%. I would not expect it to idle rough and even if it started rough due to too much fuel, I'd expect the O2 sensor to trim it to a reasonable level.
What's more likely is that the cam timing is off for one of the camshafts. Since the CAS is driven directly by the bank 2 exhaust camshaft, an advanced or retarded cam will also advance or retard the overall timing if that camshaft happens to be out of time. The fuel and ignition timing will be completely off. Cam timing also affects overall engine VE. If the banks have uneven VE's because one bank has timing off, this will cause an engine to have a power imbalance.
What's more likely is that the cam timing is off for one of the camshafts. Since the CAS is driven directly by the bank 2 exhaust camshaft, an advanced or retarded cam will also advance or retard the overall timing if that camshaft happens to be out of time. The fuel and ignition timing will be completely off. Cam timing also affects overall engine VE. If the banks have uneven VE's because one bank has timing off, this will cause an engine to have a power imbalance.
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Smileysauce
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Re: Rebuilt N/A motor, rough idle.
Okay, I believe I understand but just to be sure, and you'll have to forgive my lack of knowledge for terminology and abbreviations, when you say "V.E." what are you referring to?
Also for curiosities sake, could a more drastic jump in injector output cause this? My reasoning for asking is that I think I bought something higher than 370cc.. (I have learned the hard way in between the time that I bought these injectors and present day, not to by sensitive parts from eBay as things are not always as they seem, thus my worry of these injectors..)
I apologize for constantly jumping back to the subject of the injectors after all that you've told me. I am just not one for letting a question scratch at the back of my mind. I am definitely going to recheck my timing first before I pour money into something that may not be needed. I appreciate the help greatly.
Also for curiosities sake, could a more drastic jump in injector output cause this? My reasoning for asking is that I think I bought something higher than 370cc.. (I have learned the hard way in between the time that I bought these injectors and present day, not to by sensitive parts from eBay as things are not always as they seem, thus my worry of these injectors..)
I apologize for constantly jumping back to the subject of the injectors after all that you've told me. I am just not one for letting a question scratch at the back of my mind. I am definitely going to recheck my timing first before I pour money into something that may not be needed. I appreciate the help greatly.
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Ken@PTUNING
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Re: Rebuilt N/A motor, rough idle.
VE refers to volumetric efficiency. It's a representation of how efficient an engine is with respect to its displacement, temperature, pressure, and RPM.
At the shop, I normally see issues with cars running on injectors larger than 40-50% compared to stock. They typically won't run or start well until a new starting map has been loaded. Lucky for you, most injectors are color coded, and the same goes for Nissan injectors. Check out the link:
https://z32.wikispaces.com/Fuel+Injector
At the shop, I normally see issues with cars running on injectors larger than 40-50% compared to stock. They typically won't run or start well until a new starting map has been loaded. Lucky for you, most injectors are color coded, and the same goes for Nissan injectors. Check out the link:
https://z32.wikispaces.com/Fuel+Injector
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Smileysauce
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- Car: 1990 300ZX Z32 N/A
- Location: Tulsa OK
Re: Rebuilt N/A motor, rough idle.
Okay, i see now. Thank you for the lesson there.
On the subject of the injectors, I found my receipt that they came with, they are JECS and the part number is A46-00 (how much that would help, I don't know). When I search "JECS A46-00" I get a multitude of different results in both design and output. As for the color, I'll have to get back to you as to what I have because I am color blind. I do know that it was a darker color though.
On the subject of the injectors, I found my receipt that they came with, they are JECS and the part number is A46-00 (how much that would help, I don't know). When I search "JECS A46-00" I get a multitude of different results in both design and output. As for the color, I'll have to get back to you as to what I have because I am color blind. I do know that it was a darker color though.