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Showing results for tags 'Pressure'.
Found 5 results
High fuel pressure on boost
Timecode posted a topic in Nissan L6 ForumI'm experiencing a slight rich issue and need the groups help. Its an l28et running a JWT 550 kit in a 71 240z. Using the stock l28et fuel rail, Aeromotive FPR with psi gauge, upgraded to bigger fuel line (still using the oem return line), and an unknown in tank pump. Prior owner says its a 300zx turbo pump, but I have yet to drop the tank. I have seen it go to 65 psi with no pressure drop at all. 11.5 AFR until boost crosses the 10 psi mark, then fuel pressure shoots up 5 psi too much (relative to boost )and stays that way. At idle, fuel psi is correct. Cruising, it's correct. The problem shows up only after 10 psi of boost, thats when my AFR's go to 9.5-10.5. Myself and other can't see any smoke from the tail pipe during acceleration. I believe there is an restriction thats not allowing the fuel to return fast enough. Maybe the oem fuel rail? I don't see any pinches in the rail that would cause such a thing. Maybe its my setup. Any ideas where the restriction might be?
260z oil gauge
nitekillerz posted a topic in Ignition and ElectricalI have a 260z thats wiring wise all stock. My fuel, clock and tach(sometimes) gauges all work. My voltage is stuck somewhere in negative so I'm not sure if thats electrical issues involving alternator but i don't mind that one not working. My oil and water gauge does not work. I have a newly bought oil sender, the bullet type water temp sender(is this the sender) with single bullet connector connected but the sensor next to it with two wires coming out isn't connected because they were cut completely off. I took off gauge and put battery + terminal to ign(G) and the black wire to ground. i then grounded my oil wire(Y/B) and it only moves to the 0 position. i thought it was supposed to move all the way? Is the gauge bad? Any help is appreciated as i really can't afford one right now and don't want to run my car without either of these gauges. Also how can i tell if my water pump is working? I have no leaks but i feel the engine gets very hot very quickly. I took the radiator cap off and i thought bubbles would come out or you would see the coolant flowing or moving but it was very still. I'm afraid thats also bad.
Low Fuel Pressure (76 280Z)
Pac_Man posted a topic in Fuel DeliveryHey everyone, I've got a 1976 S30. It's effectively stock as far as the EFI system goes, all I've done is change the plug wire connectors for the injectors and I've replaced the fuel send lines with new hose. Of course I also put a new filter on it after I got it as well. During the summer, it started having an issue where it would randomly lose engine power entirely for brief moments- a number of seconds, really. Then it would pick back up and drive normally. I thought it was just crud working its way through the lines from the gas tank and I wasn't too concerned about it. Shifting up a gear would usually make it stop. Then it started to bog down on the rare occasion. It would run rough, misfire, had no power, and wouldn't rev over 1500 rpm (or if it did, it went kicking and screaming). I would drive it for a minute and then it would start running normally. On my way to my first day at a new job last month, it died in my neighborhood and wouldn't start again. My dad and I were trying to push it back that night but it was tough since it was on a slight slope. He went to get the truck to pull it back and I decided to try starting it again to see what it would do. It caught a couple times and then finally coughed back to life. I changed the fuel pump thinking it was the old one going bad. I used an Airtex pump from O'Reilly (I know, you're probably rolling your eyes now) and installed a Fram G3 between the tank and the pump to keep tank crud from messing up the pump. It worked fine for a couple days and then the issue came back with a vengeance. As it sits now, the car idles fine. Driving it, it starts to stumble around 2500 rpm and the power cuts completely at ~3000 rpm. It's almost undriveable unless I'm really careful with how high I rev. Even then, it can be fussy. The general manager of the auto shop I work for knows the car really well so he helped me diagnose it on Saturday. He checked and adjusted the TPS and AFM. We tried a new computer since we had one laying around and there was no change. He checked for leaks on the intake and found none. He removed the vacuum from the FPR on the fuel rail and fuel pressure rose accordingly which, if I've read correctly, means that the FPR is functioning properly. The last thing we did was check fuel pressure (probably should have done that first but hindsight is always 20/20). It was running at 32 psi @ idle and under load (revving the car) it would dip to ~30 psi. If I'm correct about the FPR working properly, I've narrowed it down to 3 suspects: - The G3 filter I installed between the tank and the pump - The new pump - Fuel damper near the pump I read about people installing the G3 so I thought it was a good idea. The pump is new, but it is a random O'reilly brand. Since I was having issues before and after replacing the pump, that leads me to believe that the issue does not lie in the pump setup I installed. My old OEM pump was probably still working alright for its age. As I type this, the most plausible cause in my eyes would be the fuel damper. I'm not sure what the symptoms of a bad fuel damper are, however. Anyone have any suggestions? I'm going to try running it without the filter when I get the chance, but I've been obscenely busy the last few days. Thanks. Pac_Man
rebuilt l28et has no oil flow
98cobra+75280z posted a topic in Nissan L6 ForumHey guys, hopefully someone can lead me in the right direction. I recently rebuilt my l28et that is in my 77 280z. I took my time with the rebuild and checked all the bearing clearances and replaced any and all gaskets. I also cleaned all the oil and coolant passages and made sure to triple check everything during the rebuild. I purchased a new turbo oil pump to ensure that everything in the motor was at least mostly new. Well fastforward and the motor is back in and I am attempting to prime it for first start and break in. I took the oil pressure sending unit out as well as all the spark plugs and oil fill cap. I crank the motor (or have my brother crank it) while the other looks for oil flow through the oil pressure sending unit port as well as oil on the cam. Well we have neither!! I cant figure out what it could be as the oil filter is a new bosch which I have never had problems with bosch filters pre-rebuild. And the pump is brand new and the dizzy shaft gear and pin seem fine. Any ideas would be greatly appriciated. Thanks guys
Oil pump only pushing 25 psi
98cobra+75280z posted a topic in Nissan L6 ForumI recently rebuilt my '82 l28et for my '77 and am having oil pump issues now. The car idles fine but with cold oil my mechanical only sees around 20 psi and as it warms it goes down to 12-15 like it use to. My worry worry is that with cold oil the car use to see 45-50 psi at idle and increase with revs to 60 or so. With revs the pressure never goes above 20 psi. I installed the pump and shaft like the "how to rebuild your datsun OHC" book states but ran into a problem with the oil squirt hole not lining up with the punch mark on the pump shaft gear. With the marks lined up the dizzy shaft end isn't even close to being lined up. When I line the tang of the dizzy side up to where it needs to be the marks on the shaft and pump housing no longer line up. The pump is off an '83 turbo motor where as the shaft is from the '82 motor. I don't see how the shaft mark needs to be lined up with the pump housing since the shaft just spins along with the motor but maybe I'm wrong in this thinking. I am planning on getting a different gauge to see if maybe my gauge is faulty. Taking the oil cap off I do see oil squirting up to the cam but I am not sure if it is a sufficient amount. Any ideas on what may be causing my lack of oil pressure. Oh and the oil pick up tube is free and clear from debris as well. Thanks guys, Kevin