Draker Posted June 20, 2015 Report Share Posted June 20, 2015 The CAS (Crank/Cam Angle Sensor) simply tells the ECU where the engine is in the rotation and calculate RPMs. Based off of this reading, the ECU(or PTU) can make decisions on when to fire plugs and injectors, how much fuel is needed, etc. The O2 sensors read amount of oxygen in the exhaust and report that to the ECU to trim fuel as needed. There are a bunch of other sensors that are also taken into account when determining how much fuel is needed. For example the Mass Air Flow Sensor(MAF)/Manifold Absolute Pressure(MAP) sensor, Engine Coolant Temp(ECT) sensor, FTS (Fuel Temp Sensor). ((Some of which the KA might not have)) This might sound complicated but it's pretty simple. I'm by no means a KA expert, this is just EFI theory. 2 Quote Link to comment
Rhino13 Posted June 20, 2015 Author Report Share Posted June 20, 2015 Alright, well I understand the past replies much more now. Thanks Craig. I'm really looking forward to getting everything together so I can visually see how it's all hooked up. I know I'll have questions when I'm hooking it all up, but it'll be another learning experience. 2 Quote Link to comment
Brohemius Posted June 20, 2015 Report Share Posted June 20, 2015 Stoked to see you slap a sweet engine in your truck ryan! Youve got a nice 720, the body is clean as hell and now the engine will match! Also excited to learn with you lol. 3 Quote Link to comment
Rhino13 Posted June 23, 2015 Author Report Share Posted June 23, 2015 Alright so while I wait on the ka I decided to check up on the z24 since it's been sitting since I got home Canby. I lost an exhaust manifold bolt on the way home but didn't notice until it was already hot, so we kept going. Just replaced it with one I got from Harlow and noticed the other 3 bolts holding that side of the manifold on we're loose, and one of the bottom stud's will tighten up decent, but then skip and get loose. Is that a normal stud that I can take out and replace? I'm thinking of doing both manifolds and a head gasket soon just to freshen it up a bit and not throw too much $ at it. 1 Quote Link to comment
Draker Posted June 23, 2015 Report Share Posted June 23, 2015 From what you are describing it sounds like the lower stud might be stripped? That could be a bit of work to get that fixed correctly. Of course the easy win could be a heli-coil or a more expensive time-sert. You could always drill it and tap it larger. 1 Quote Link to comment
Rhino13 Posted June 23, 2015 Author Report Share Posted June 23, 2015 Yeah sorry, didn't make that clear haha. The bottom one closest to the cab is stripped. So are they pressed in then? If they are threaded in I may be able to cut off some of the stud once the manifold is off and catch threads with bolts to back it out. 1 Quote Link to comment
Draker Posted June 23, 2015 Report Share Posted June 23, 2015 Yeah sorry, didn't make that clear haha. The bottom one closest to the cab is stripped. So are they pressed in then? If they are threaded in I may be able to cut off some of the stud once the manifold is off and catch threads with bolts to back it out. They are threaded into the head. 2 Quote Link to comment
Rhino13 Posted June 23, 2015 Author Report Share Posted June 23, 2015 Thanks Craig. Well I drove it a bit today, and after shutting it off for about 10 minutes it started shuttering and stalled. I found a vacuum hose going into the intake from the air cleaner that came off so I hooked it back up, drove it another bit and the next time I drove the same thing happened. The vacuum hoses all check out, I can hear the pump and the float bowl has plenty of fuel. I'm pretty stumped at what it could be, the pump and filter are new, oil is clean maybe a little gas smell, and everything appears to check out. 1 Quote Link to comment
Charlie69 Posted June 24, 2015 Report Share Posted June 24, 2015 Exhaust Manifolds are one of the things that need to be check often to be sure they are tight.. 1 Quote Link to comment
Rhino13 Posted June 24, 2015 Author Report Share Posted June 24, 2015 Exhaust Manifolds are one of the things that need to be check often to be sure they are tight.. Good to know, thanks Charlie. The truck starts and runs fine now but I'm leaving it close to the shop overnight, I want to check fuel system and hopefully put my Weber on and delete all of the vacuum lines other than the advance. I got the rebuild kit, just have to get the adapter made by our shop neighbor. 1 Quote Link to comment
Rhino13 Posted June 24, 2015 Author Report Share Posted June 24, 2015 Well I drove it a bit today, and after shutting it off for about 10 minutes it started shuttering and stalled. I found a vacuum hose going into the intake from the air cleaner that came off so I hooked it back up, drove it another bit and the next time I drove the same thing happened. The vacuum hoses all check out, I can hear the pump and the float bowl has plenty of fuel. I'm pretty stumped at what it could be, the pump and filter are new, oil is clean maybe a little gas smell, and everything appears to check out. Still have this issue of it'll run fine for 10-20 minutes, then start shuttering and die, and won't restart until it's sat a while. Quote Link to comment
Draker Posted June 24, 2015 Report Share Posted June 24, 2015 Sounds like a it's heat related. Stock carb? Quote Link to comment
Rhino13 Posted June 24, 2015 Author Report Share Posted June 24, 2015 Sounds like a it's heat related. Stock carb? Yup it's stock, I have a Weber I just don't want to fork out $45 for the new adapter. It's not overheating according to the gauge, and its always been accurate. Quote Link to comment
Draker Posted June 24, 2015 Report Share Posted June 24, 2015 Not over heating, but heat related. Engine runs good when cold.. it heats up to normal operating temperature after 10-20 minutes and it dies. Perhaps an issue with the choke on the carb? These are all guesses. Quote Link to comment
Rhino13 Posted June 24, 2015 Author Report Share Posted June 24, 2015 I was thinking it could be choke related, but it's disconnected and the butterfly's are zip tied open from when it broke. I think it may be vacuum related, all of the vacuum lines got all crispy from being so hot on the way home from Canby. They were all pretty brittle to begin with. I couldn't find any more broken pieces, but the AB valve has quite a bit of electrical tape on it... Quote Link to comment
uberkevin Posted June 24, 2015 Report Share Posted June 24, 2015 Shit like this pisses me off, hope you find out what the problem is. Quote Link to comment
arizonajones Posted June 24, 2015 Report Share Posted June 24, 2015 I actually had a vacuum leak from the AB valve on mine (the small line that connects it to all the air cleaner stuff) and it ran pretty terrible once it warmed up. My choke was working though, so as soon as the choke opened and leaned out the mixture it would die. Always worth it to just put fresh rubber lines everywhere though. Pretty cheap fix. Does it keep running if you keep the rpms up above idle, or does it die no matter what? 1 Quote Link to comment
Draker Posted June 24, 2015 Report Share Posted June 24, 2015 This might help you: http://www.nicoclub.com/archives/nissan-720-pickup-truck-vacuum-hose-diagram-repair-guide.html 2 Quote Link to comment
Rhino13 Posted June 27, 2015 Author Report Share Posted June 27, 2015 Thanks for the replies guys. The truck wouldn't idle even if you feathered the gas, it ended up being yet another vacuum line hidden under the power steering pump. Didn't find it until I already had the carb off because I bought a Weber adapter today so I just went ahead and deleted just about everything. It looks much better under the hood now, but I couldn't get my fuel pump to prime due to a bad connection, and once I got it hooked up I didn't have time to purge it again. I have faith it'll run awesome once I have it tuned up. 2 Quote Link to comment
denmarkboy Posted June 27, 2015 Report Share Posted June 27, 2015 Thanks for the replies guys. The truck wouldn't idle even if you feathered the gas, it ended up being yet another vacuum line hidden under the power steering pump. Didn't find it until I already had the carb off because I bought a Weber adapter today so I just went ahead and deleted just about everything. It looks much better under the hood now, but I couldn't get my fuel pump to prime due to a bad connection, and once I got it hooked up I didn't have time to purge it again. I have faith it'll run awesome once I have it tuned up. Sounds like you got it . I will be on the road again today but hit me up if I can lend some info . We need to have a BBQ I'm getting lonely on Saturday's . We should take the party to the lake . 2 Quote Link to comment
Rhino13 Posted June 27, 2015 Author Report Share Posted June 27, 2015 Thanks Al, I appreciate all the help so far. I'm down to have a BBQ at a lake, I still have to come down to your place soon anyway so let's try to set something up. 1 Quote Link to comment
Draker Posted June 28, 2015 Report Share Posted June 28, 2015 Man, when I had my 720 I would have killed that for AC setup. :) Quote Link to comment
Rhino13 Posted June 28, 2015 Author Report Share Posted June 28, 2015 Man, when I had my 720 I would have killed that for AC setup. :) Too bad it doesn't work :( I'm removing it because I don't have a condensor. Quote Link to comment
Brohemius Posted June 28, 2015 Report Share Posted June 28, 2015 Heres a picture of that component you are trying to identify. Anyone know what this is for? Quote Link to comment
datzenmike Posted June 28, 2015 Report Share Posted June 28, 2015 One is the vacuum switch for the single plug operation. Low vacuum indicates heavy throttle use. Switch closes and grounds the 4th (White) wire going to the distributor module. This shuts off the exhaust side plugs to reduce engine noise until throttle is lifted. The other is a vacuum switch that senses deceleration at high speeds (high vacuum) and allows the idle cut solenoid to shut off or close. This saves the fuel normally sucked in during deceleration from being wasted out the exhaust. Naturally, other switches like the clutch must be engaged and the transmission in gear to prevent stalling. When the intake vacuum drops to normal the system shuts off and the idle cut turned on. This is an emissions device that actually saves fuel. 1 Quote Link to comment
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