zigen9 Posted July 13, 2013 Share Posted July 13, 2013 I have a question about my Nissan rb25det. It starts good when the engine is cold. But when the engine is hot. It cranks but won't start. Here is what I've done so far. -I have changed all my spark plugs.still no help. -When my engine is cold, I turn my key I can hear the pump is on (because there is a noise from the fuel pump)even I switch my fan on to level 3 I can still hear the noise from the pump. -When hot engine, car is off. I've tried to turn my car on. I can hear the pump if my fan is off or in level 1. If I turn my fan on to level 3 and then turn on my car, then I cannot hear the pump. I have to turn the fan off and then try to crank my car. But still it won't start when engine is hot. - Put starting fluid in to intake manifold. success. it starts when Hot!!. But if I turn off the engine and try again. It won't. I have to put starting fluid again. I don't want to try too many times with this starting fluid. Because it's harmful to my engine. My conclusion is the fuel pump might be bad, fuel filter maybe?. Any other method to do more diagnosis. I really want to fix this part, and I fixed all mechanical of the ride. Please let me know, if there are any solution. Would be much appreciated. Quote Link to comment Share on other sites More sharing options...
ZT-R Posted July 14, 2013 Share Posted July 14, 2013 Yea kinda sounds like the fuel pump might be on the way out. What kind is it? How old? Wired with a relay or what? Quote Link to comment Share on other sites More sharing options...
zigen9 Posted July 14, 2013 Author Share Posted July 14, 2013 I have a feeling is the fuel pump. It's the MSD 2225. I believe it was changed probably 2.5-3 years ago. Yes it's wired with relay, but the that hot wire for the fuel pump does underneath the car (the guy who did the swap, put this hot wire underneath, which it needs to be re-wired). Do you think that will be a problem of the wiring? Quote Link to comment Share on other sites More sharing options...
ZT-R Posted July 15, 2013 Share Posted July 15, 2013 You could try swaping the relay out for a new one. I would just make sure the wire is fused so it it grounds out it pops a fuse first. I would prefer the wire be inside for as long as it could be but, no huge issue. Quote Link to comment Share on other sites More sharing options...
zigen9 Posted July 16, 2013 Author Share Posted July 16, 2013 Thanks I'll check it out tonight. Most likely I'll get another pump. incase there is no fuse. What amp of fuse should it be?? Quote Link to comment Share on other sites More sharing options...
dwarlick Posted July 17, 2013 Share Posted July 17, 2013 I would suggest adding a fuel pressure gauge as well. This would help with diagnosing this problem and other issues in the future. Quote Link to comment Share on other sites More sharing options...
ZT-R Posted July 17, 2013 Share Posted July 17, 2013 Fuse depends on what pump, probably a 15-25 Quote Link to comment Share on other sites More sharing options...
zigen9 Posted July 18, 2013 Author Share Posted July 18, 2013 I just brought a Bosch pump. How do I check how many amp of fuse to put with the pump?? if I put the fuel pressure guage. Around what degree is the normal pressure ?? Quote Link to comment Share on other sites More sharing options...
dwarlick Posted July 19, 2013 Share Posted July 19, 2013 (edited) The fuel should recirculate and maintain an ambiant temperature because it recirculates back to the tank and cools. It will have a rise in temperature as it approaches the heated fuel rail of a hot engine but it is moving at such a high velocity it should not rise too high. A faulty or cavetating pump will also cause an abnormal fuel temp rise. Also the act of the pump compressing will rise fuel temp but under normal operation not to the point of vaporazation. The reason I suggested a pressure guage is that when I was having motor issues it provided instant feedback as to what was going on with the fuel system. I had issues with the tank pickup, the lift pump, multiple clogged fuel filters and the surge tank. These issues were more quickly isolated because as I saw a rise to high RPM the fuel pressure would drop off to nothing and the motor would fall on its face. Edited July 19, 2013 by dwarlick Quote Link to comment Share on other sites More sharing options...
zigen9 Posted July 22, 2013 Author Share Posted July 22, 2013 Thanks for the advise dwarlick. I brought a jaguar bosch external pump, one part I'm not to sure is which side is the fuel tank hose. Let me attach a picture of the pump. I'll look into the fuel pressure guage also. I don't think is too hard to install it correct?? Quote Link to comment Share on other sites More sharing options...
zigen9 Posted July 22, 2013 Author Share Posted July 22, 2013 This is the type of pump I brought, Is the thread part side of the pump from the fuel tank??? Because the MSD I have look a bit different. Please let me know. Quote Link to comment Share on other sites More sharing options...
zigen9 Posted July 29, 2013 Author Share Posted July 29, 2013 Anyone can show me some lights? Quote Link to comment Share on other sites More sharing options...
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