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411 HP GSXR / 203 HP Vrod
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Discussion Starter #1
I had the extra Supra fuel pump installed with an HKS Fuel rail and 720 cc injectors, VPC chip and fuel pressure regulator and I have hell in the morning with startup. The car has to be cranked at least 7 times to "catch" and then it puffs dark smoke until it clears itself up. Once the car is warm it's okay except for the fact that at least one time per day I would be driving down the road and the car just cuts off. I will start it while coasting and then everything would be fine. What could this be?
 

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Check your fuel pressure, check to see if BOTH pumps are working, and reset your ecu. Dont HONESTLY know if this will help, but give it a shot. Wish I knew the exact answer for your problem.


stephen
 

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Twin pumps

I'd say make sure both pumps are operating also.. Check the wiring for your pumps. It might not hurt to check and make sure both of the pickups for the pumps are in the sump in the tank, and arent interfering with each other too much.

Whats your idle fuel pressure?
 

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Yes, brothers own Supras
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Check your pump wiring. I have the exact same setup. I have the sound-performance kit. No disrespect to Larry but the wiring with the kit sucks ass. I think it is like 16 guage. I was having major voltage problems and the car would cutoff when I stopped. What I did was run a single 4 gauge wire the length of the car back to the pumps and then 2 8 guage wires to the pumps. I have an upgraded alternator also.
 

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Super Moderator!!ON PATROL ALL OVER!!
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talk to henry from the nemkiv forum he can help you out as he has a special mod he made for just such a thing i think hes getting it patented too!
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #6
Thanks for the input guys. I'm absolutely pissed about this because I just spent over $10,000 for everything and my car doesn't even start reliably anymore. I'm going to get a fuel pressure gauge today and I'll keep you guys informed...
 
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Your post mentions that dark smoke comes out after your car finally starts, that sounds like a rich condition to me. If this is the case, considering your mods this would most likely be the result of too high a fuel pressure level, or it could be something else entirely like an electronics issue from the VPC. If you had a lean condition you would not see dark smoke on start-up, in any case the fuel demand at engine crank could almost be supported by a hand squeeze bulb let alone the 2-pump setup you have.
 
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check your battery voltage while enigine idling. if its under or quit 12 volt your car is running on the ecu emergency programm in the ecu. That means that the ecu gives your engine tonns of fuel at idling until it dies. I had the same trouble, I cheched my alternator (should load arround 14,9 volt, if not change the alternator or the power regulator in the alternator) while engine idling and I got 14,9 volt on the alternator but only 12 volt at the battery....... I checked all connectors between the alternator and the fuse case, and the fuse case to the battery. there was nothing to see visible about corrosion, but I decide to solder all connectors again.
After finish by job I had 14,9 volt at the alternator and 14,9 volt at the battery at idling.
I was searching for this problem for about 2 weeks daily at 5 hours..............
hope it helps. check it, it sound like this problem. I got this bad problem over night......
Markus
 
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That’s a good idea to check the battery voltage. I recommend checking it while you are cranking the engine and ensure that it is over 12 volts (while cranking). The voltage at rest should be just under 13 volts (engine off). If you have a low voltage condition in the battery, which could easily happen from battery damage caused by having the car sit for awhile, the ECU can send some strange commands to the injectors...

Good luck!

Bob
97 6-speed
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #10
You guys aren't going to believe this... I keep my VPC tucked in a crevace below the steering wheel (Because my son would turn the knobs) so I pulled it out and decided to turn the gain back 2 clicks. Upon doing this I noticed that the car wouldn't start. Then I figured what the hell, maybe this thing needs MORE fuel (Which I doubted) so I turned the gain up two clicks from the original position and "Whamm" the car started up on the first try. I figured it must have been a fluke so I decided to wait until the next morning to see how it would start since the mornings are usually when it would give me hell. Well, this morning I got in the car, turned the key and it started right up! Damn I'm happy! The one thing I noticed was that before when it would act up in the morning the idle would stay down upon warmup around 1,000 RPM whereas now it idles up like it is supposed to at around 1,600 I believe... Hey guys, I want to thank everyone who provided input on this. Hopefully I can help you someday. Peace.
 

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OK, Heres the deal. Did you get a fuel pressure gauge yet? I believe the gain is used to richen / lean out the fuel. Get a fuel pressure gauge and make sure it is at 40-45 psi when static(car is not running, jsut the fuel pumps). I was having a problem with my car running WAY to rich until Larry at Sound Performance told me what to look for. Good luck. Glad you got it running.


stephen
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #13
Ok guys, I bought a fuel pressure gauge today and installed it. When I started the car it read 19 psi. I figured this was way low so I have it at 30 psi now. Where should I be? Everything seems to be okay so far except for the fact that when I'm pulling up to a stoplight the idle comes down very slowly now. (Running rich?) Also, I was at a gas station and upon leaving I saw a motorcycle headed in my direction. I got behind him immediately from the gas station and floored it for about 5 seconds then let up once I caught him then all of a I noticed that the car wasn't responding when I tried to accelerate! I was like WTF! Anyway, I chilled out for a second and the problem went away. I headed to a highway where I could analyze the problem but for 5 miles I hammered the car and it never happened again. Maybe upon leaving the gas station the car hadn't obtained proper fuel pressure just yet? At this point I'm going to check my voltage and have the car fine tuned at a local shop. Peace.
 
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You should get full pressure less than a second after your pumps kick on. 30psi is way too low. You should have it set at about 45psi (static, vacumn line disconnected). Then tune back the VPC to have to running at the right mixture.
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #15
45 psi? Really? So which vacuum line do I disconnect? Give me a brief rundown on the procedure. Thanx.
 

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This is the way I can check mine. Turn the key to Accessories, but do NOT start the car. THe fuel pumps should be flowing, at least both of mine do at this point and they are loud as crap. That will give you your static fuel pressure as the car sits there but is not started. The fuel pressure should be between 40 and 45. If you are runing WAY RICH, you will know it. You will be dumping black smoke out.


stephen
 
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HKS T04R said:
45 psi? Really? So which vacuum line do I disconnect? Give me a brief rundown on the procedure. Thanx.
Presuming that you have a full fuel system, including the Fuel Pressure Regulator (adjustable one). There is a vaccum line running into the FPR, so pull that off (carefully, air barb is small and brittle) and you should have the pressure set at 40-45PSI at idle (adjust the top FPR nut). 30 is too low. Then connect back the vacuum line, and from that point on your fuel pressure will go up as the boost goes up (1PSI fuel pressure per 1PSI boost).
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #18
I started the car up this morning showing 30 psi fuel pressure and 7 seconds later the fuel pressure shot up to 37 psi and the car cut off. The car ran rich (Barely running) for 3 minutes as the fuel pressure went up to 40 psi and finally cleared up when I drove off from home. About 5 minutes later I got out to check the fuel pressure while the car was running clear and it was at 30 psi but my exhaust pipe was emitting black smoke even at idle. 30 psi is too much for some reason. Is this due to the fact that I have low voltage and the ECU is in emergency mode?
 
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Yes that could be possible, I had this problem as you can see on my earlier post in this thread. figure out if the alternator charges like he should. What kind of plugs do you run, are they new?
Markus
 

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element217 said:
This is the way I can check mine. Turn the key to Accessories, but do NOT start the car. THe fuel pumps should be flowing, at least both of mine do at this point and they are loud as crap. That will give you your static fuel pressure as the car sits there but is not started. The fuel pressure should be between 40 and 45. If you are runing WAY RICH, you will know it. You will be dumping black smoke out.


stephen
The pumps will only run if you have the 12v mod done. I trigger my second pump off the primary pump after the 9/12 controller, so they only run when the motor is running(controlled by the ecu)... I do have a way to manually run one pump so I can check the pressure though....

FOR HKS T04R... Do they have the FPR vacuum line running through the factory VSV valve like the stock regulator or is the source straight off the intake?
 
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