btd19m Posted August 24, 2015 Author Report Share Posted August 24, 2015 I just replaced the filter. Putting my hand over the filter gives no change. Any chance the intake isnt connected at the base or theres a gap somewhere? Quote Link to comment
btd19m Posted August 24, 2015 Author Report Share Posted August 24, 2015 the 81 720 had an L18 5 speed here. and the missing bolt through the filter does what/ blocks what? Quote Link to comment
Doctor510 Posted August 24, 2015 Report Share Posted August 24, 2015 Best guess here is: While it's running you put your hand over the snout, no suck? Just maybe it's sucking air thru the cold air fitting on the bottom of the snout. Shucks man, if it runs, its drawing air. Missing bolt is a non-issue connects the air cleaner to the bracket. Quote Link to comment
btd19m Posted August 24, 2015 Author Report Share Posted August 24, 2015 ^^ is acting as an intake Quote Link to comment
banzai510(hainz) Posted August 24, 2015 Report Share Posted August 24, 2015 OK if had stuff in the fuel filter before then ck it again. maybe its plugged. This is a L motor and should be pretty simple to figure out. Knowing what I know about L motors is I ck the valve lash then ck for tightness on carb and manifolds Ck the dist for loose shaft and spark , if points c the point and condensor then ck carb if very old a weber32/36 is planned for the next soon upgrade. that hole isnt going to do anything. You should be able to run the truc with out the whole aircleaner on there Quote Link to comment
btd19m Posted August 24, 2015 Author Report Share Posted August 24, 2015 its a factory carb. never had a rebuild. the l18 never had a single thing done apart from fluids. and d21 break cylinders (mast/slave) and a d21 clutch cylinder a weber is an 800 dollar upgrade here. even a clone is 400$ (not going to try a clone just putting it out there) Quote Link to comment
btd19m Posted August 24, 2015 Author Report Share Posted August 24, 2015 carby isn't blocked near as i can tell. Quote Link to comment
flatcat19 Posted August 24, 2015 Report Share Posted August 24, 2015 Is the throttle restricted? Does it move freely? Quote Link to comment
btd19m Posted August 24, 2015 Author Report Share Posted August 24, 2015 It does from time to time it randomly loses throttle. today in 5th at 110kmh it just dropped the throttle for a bit with the pedal to the floor it just didnt wsnt to rev up then suddenly it responded Quote Link to comment
flatcat19 Posted August 24, 2015 Report Share Posted August 24, 2015 Grab the throttle wheel on the carb. Do you have a specific thread for your truck? Rather than making 29 separate threads, making 1 thread will keep all your problems and knowledge in one spot. It's like inviting someone in to your garage by having a build thread. 1 Quote Link to comment
datzenmike Posted August 24, 2015 Report Share Posted August 24, 2015 Your throttle is stuck open. Maybe you jammed it while changing the filter. This can't be so hard to figure out. Shut it off and look down the primary and secondary throttle bores to the bottom. Use a flashlight and check the brass throttle plates. One is part open. Yes you need a build thread and I'll move these 20 odd posts all there for you. Like a scrap book you can look up anything you have done to it. 1 Quote Link to comment
datzenmike Posted August 24, 2015 Report Share Posted August 24, 2015 It will probably still work wired backwards but the spark will be jumping from the ground to the electrode tip rather from the tip to ground. Quote Link to comment
btd19m Posted August 25, 2015 Author Report Share Posted August 25, 2015 It will probably still work wired backwards but the spark will be jumping from the ground to the electrode tip rather from the tip to ground. yeah as far as i know its never had spark problems. its a factory distributor and i have a factory coil afaik Quote Link to comment
btd19m Posted August 25, 2015 Author Report Share Posted August 25, 2015 http://community.ratsun.net/topic/67161-my-up720datsun-dualtwin-cab-project-running-waterdual-bats-air-shocksbullbarcanopysound-system-upgrades/ and im uploading some stuff now. (videos) first start is 2000rpm. timing is normal. anywhere below 2000 it stalls out changing mix doesn't do anything to fix the issues. Quote Link to comment
flatcat19 Posted August 25, 2015 Report Share Posted August 25, 2015 If you already have a thread going what's with the 28 other threads you have started? :poke: 1 Quote Link to comment
datzenmike Posted August 25, 2015 Report Share Posted August 25, 2015 my 720 is not intaking any air now from the filter. No idea whats up. Dont even know where to start being used to a holly and all. Replaced the air filter as well. Its not blocked. And the motor the last day or two is reving dangerously high and Temps are pushing redline. Last hour or so its struggling and pushing 7000. Somethings wrong. No idea what. Changing idle seems to last a few hours then it juat goes back to this. Carb is not blocked and throttle return is normal. No smoke for now. Also had suprise rain today. Cab is full of water in the floor pans. Motor is seemingly uneffected. Also starting to have issues with the pedal (gas) not working/responding. Even idling or in some cases losing power on the freeway at 110km/h. http://community.ratsun.net/topic/67161-my-up720datsun-dualtwin-cab-project-running-waterdual-bats-air-shocksbullbarcanopysound-system-upgrades/ and im uploading some stuff now. (videos) first start is 2000rpm. timing is normal. anywhere below 2000 it stalls out changing mix doesn't do anything to fix the issues. We know it's revved up. Only way for this is the throttle is open. Part open, stuck open. Instead of a video take a look for the problem, can't be that hard. Your throttle is stuck open. Maybe you jammed it while changing the filter. This can't be so hard to figure out. Shut it off and look down the primary and secondary throttle bores to the bottom. Use a flashlight and check the brass throttle plates. One is part open. Quote Link to comment
btd19m Posted August 25, 2015 Author Report Share Posted August 25, 2015 point is today its suddenly okay. yesterday it was not, https://www.youtube.com/watch?v=ktFzqZCXIT0 about 30 minutes now and rpms have gone from 1200 idle to 4000-5000 idle throttle isnt jammed right now. could it be getting stuck somewhere? Quote Link to comment
flatcat19 Posted August 25, 2015 Report Share Posted August 25, 2015 Again...go grab the throttle wheel on the carb and twist it. You are trying to feel if it gets hung up or tight. Look down the carb and see if there is something in there causing a restriction. No one is going to do it for you. Quit asking the same thing over and over when the answer has already been handed to you. Put your spoons away. This guy isn't even trying. Quote Link to comment
btd19m Posted August 25, 2015 Author Report Share Posted August 25, 2015 figured it out. need a throttle return spring. (old one is returning most of the time but not all the time) anyone got a part number (factory carby l18) 1 Quote Link to comment
datzenmike Posted August 25, 2015 Report Share Posted August 25, 2015 That tach is stuffed. Reading twice as high at least. When you rev it up that's only 3-4K by the sound of it. No way that's reading right so you don't have a problem. When started up cold the fast idle is on so 4K reading but really about 1,800 to 2,200. Explains everything. Quote Link to comment
5t341tH Posted August 25, 2015 Report Share Posted August 25, 2015 yea i agree. just watched the video. make sure its on 4cyl mode behind the tach. I believe universal ones have options for 4/6/8 cyl Quote Link to comment
datzenmike Posted August 25, 2015 Report Share Posted August 25, 2015 Must be on 2 cylinder. Quote Link to comment
btd19m Posted August 25, 2015 Author Report Share Posted August 25, 2015 Its on 4 cyc. Dont have the resistor in though. Dont get any reading if i solder one in line Quote Link to comment
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