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Nsx cranks awhile before starting?

Anyone know the part number for a 95' for the fuel pump relay?
 
Mine does that too. When its cold it starts on the dime however, if I drive her for a while and make a pit stop after she's warmed up it wont crank over. So what I have to do is take the key out and turn to let the fuel pump start and then crank her over and at the same time give it a little gas. After a couple of cranks, it turns over and starts. Keep in mind this only happend once in a while not consistently. I wonder if it might be fuel pump? Or pump relay? Ive changed main relay and fuel filter already.

Same for me. Colds starts are fine but at time when the car is warm it does exactly what you say. I already changed the main relay... might be a good time to check out the fuel pump relay as well then.
 
Have any of you guys changed the fuel pump relay & stopped the long cranking problem?
 
I have a SOS supercharger managed with a HKS fcon pro. Cold starts were never an issue but warm starts occasionally took a few cranks.In any event, a good friend of mine who I consider a master tuner came to TO. The first issue....the IAT sensor when heat soaked fooled the ECU into thinking the car was overly hot when in fact it was not....he dialed this out. Secondly, he reduced the amount of fuel being injected on start up after 165 f. Problem resolved.It now starts in all conditions with one crank.
Hope this helps.
 
I had this problem on my 2000. I also had an intermitent no start but could wait and it would start right up just like a main relay problem. I knew about main relay problems from past Acura's and also replaced to elimate the posibility of this being the cause along with swapping relay. The car finally broke down and would not start. I had to have it tow it to my shop. The problem was the fuel pump resistor. It's function is to slow the fuel pump down to for noise reduction in the car at idle when not much fuel is needed. At least that is what I found through research on it's function. I disconnected it to verify the fix and ordered a new one to replace. The location is in the engine compartment on passenger side firewall. I looked on Prime when I was trying to figure out the problem but unless I missed it have never seen this failure mentioned. Thought I would share this in case anyone else is chasing this intermitent problem.
 
I had this problem on my 2000. I also had an intermitent no start but could wait and it would start right up just like a main relay problem. I knew about main relay problems from past Acura's and also replaced to elimate the posibility of this being the cause along with swapping relay. The car finally broke down and would not start. I had to have it tow it to my shop. The problem was the fuel pump resistor. It's function is to slow the fuel pump down to for noise reduction in the car at idle when not much fuel is needed. At least that is what I found through research on it's function. I disconnected it to verify the fix and ordered a new one to replace. The location is in the engine compartment on passenger side firewall. I looked on Prime when I was trying to figure out the problem but unless I missed it have never seen this failure mentioned. Thought I would share this in case anyone else is chasing this intermitent problem.

Thanks, I was about to place an order for parts and was contemplating adding the fuel pump resistor to the cart.




edit: I cleaned out my ignition switch & the car starts up much faster. It is cranking for far less time before it starts up now.
 
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Not really.

If the main relay is dead you can crank the engine until the cows come home and it will not start because the ECU and / or the fuel pump are not powering up. A failing main relay may lead to hit and miss starting before it eventually fails completely. A main relay that has not operated will usually give you the tell-tale that the check engine light does not come on when you first turn the key to run. The fuel pump relay (really the fuel pump resistor by-pass relay) has no function during starting so is not contributing to your problem.

All first gen NSXs are getting old. Some older than others. The fuel pump has a check valve on it the purpose of which is to try and retain fuel and some fuel pressure in the fuel lines following engine shut down. If the check valve is worn or gets a piece of debris in it, it may not close off when you shut the engine down allowing for fuel leakage back into the tank and loss of pressure. Lose enough fuel back into the tank and the fuel pump prime pulse that occurs when you first turn the key to run may not be sufficient to pressurize the system which then results in a lean fuel mixture (hard to start or no start) until the pump has run long enough to pressurize the fuel lines.

My 2000 will do this perhaps once every 2 - 3 months. Just infrequent enough that it causes a little panic attack because I am used to a consistent 1-2 second delay on start up. If it doesn't start I don't keep on cranking. I just turn the key back to run and then try the start again. It always returns to its normal start-up time of 1-2 seconds.

If your starting problem is infrequent and always resolves itself when you try a second time, then I suspect its loss of fuel pressure. If the problem does not resolve itself then it might be something other than loss of fuel pressure while the engine is off.

Loss of fuel pressure can be caused by a leaky fuel pump check valve, a fuel pressure regulator that is failing to close off or drooling injectors. However, if its drooling injectors the problem would occur on every restart after the car had sat long enough to lose fuel through the injector(s). The fuel pressure regulator could have the same problem with debris holding it open; but, the more common problem is wear causing it to fail to close off the by-pass line on shut down. The leaky regulator would be more like the injectors and you would have a consistent hard start problem. The check valve problem can be hit and miss until the point at which the check valve completely stops closing. The check valves are typically integral to the pump so replacement means a new fuel pump and all that associated hassle.
 
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