thefridgeisempty Posted January 26, 2014 Report Share Posted January 26, 2014 NOVICE ALERT!!!! I have not owned this truck long. I have no business owning this truck, except that I do want to learn. Assume I know nothing. Thank you for your patience. Right, so it's got that DGEV carb on it, has been backfiring since day one and has finally gotten bad enough to drive me to post something after annihilating my muffler. Sick of it. Joe mechanic says "You got more carb than engine" but I see a lot of these swaps; seems like the thing to do. Put new gaskets in but of course that did nothing. Tinkered with that mixture screw and that idle screw to no avail. That's the extent of my understanding. Here it is, I'm suspicious of the big hose coming off the filter housing and into the the top of the engine. That just doesn't make sense to me. If that's right, can anybody tell me what's going on there?: (I'll figure out pictures, heres a link:) https://drive.google.com/file/d/0B9e1LERbEIIzOGFoQ0ZLMVlIc0U/edit?usp=sharing Anyway, what's happening, what am I looking for, don't make fun of me, I love you all, and thank you very much! Oh, and for future reference, should I post this in "engines" or "620" like I did? Quote Link to comment
datzenmike Posted January 26, 2014 Report Share Posted January 26, 2014 Exploding muffler? This sounds like an interrupted ignition to me. Failure to ignite the fuel air allows it to enter the exhaust. When the ignition fires another cylinder it lights off the fuel/air in the pipes and boom. Usually on deceleration. Needs more info. Year of truck will say if points or electronic ignition Exhaust backfire??? accelerating or decelerating??? Quote Link to comment
thefridgeisempty Posted January 26, 2014 Author Report Share Posted January 26, 2014 Right so I was content with the gurgles and farts and burps. A couple weeks back it was quite a bit colder out, took my foot off the gas, could feel/hear that build up with a looooong delay, thought "OH $#!+" and then there was a cloud of snow behind me and I was driving a motor boat. It was like a land mine, never close to that bad before. Impressive, really. Quote Link to comment
Kirden Posted January 26, 2014 Report Share Posted January 26, 2014 Firstly, welcome to ratsun and datsuning. Usually this would be posted in the engine section, but many people will help non the less. There are some nazis here, but we don't tell them that... If you can provide the year that will help, but if your truck is 75+ it should have the L20B. In that case, unless the jets are totally off, the 32/36 weber should be perfect or even a little weak for your engine. I'm running a 32/36 on my L18 and have never tuned it but still don't have this pop. It sounds like you have an ignition problem to me. Does your truck still smoke badly since the latest bang? It could have detonated and damaged something internal. If I were you I would check the timing (there is a video on this site about changing a headgasket that will be very helpful for timing). Also, check your plugs, wires, distributor parts (cap, rotor) and all of the electrical connections to your distributor and coil. I had a loose connection to my coil and had issues of bogging and deceleration on bumpy roads. Once we found it it cleared up. Quote Link to comment
datzenmike Posted January 26, 2014 Report Share Posted January 26, 2014 First off... Ensure that your wiring is clean and dry and looks in good condition. I carefully pull one wire at a time and wipe down with a WD-40 soaked rag. This allows me to visually inspect it completely and remove oil and crap from the silicon/rubber covering. Check that you have NGK plugs for your year of motor. Clean on the outside and properly clean and gaped on the inside. Check the distributor cap for cracks or carbon tracking. Carbon tracking will look like a fine crack where the spark is arcing between plug wires or to a ground. Is the cap dry inside??? very important as water will condense inside without having to drive in the rain. Is the small carbon conductor to the top of the rotor all worn out??? Is the rotor in good shape or all burnt looking? Coil. Are the wires clean and tightly bolted to the terminals? Is there evidence of carbon tracking on the Bakelite surface of the coil between the high voltage electrode and the negative terminal? Still don't know the year... so look at the points. Are they all burnt and eroded? NOVICE ALERT!!!! I have not owned this truck long. I have no business owning this truck, except that I do want to learn. Assume I know nothing. Thank you for your patience.. The only requirement for owning a Datsun is that you want to learn about them. Every owner started out this way. Quote Link to comment
ggzilla Posted January 27, 2014 Report Share Posted January 27, 2014 Weber DGEV runs OK even on a 1.2 liter engine, so the size is not the problem. Engine tune-up or carb jetting is the problem. Quote Link to comment
dr.feltersnatch Posted February 2, 2014 Report Share Posted February 2, 2014 hard to see but in the pic it looks like he has a match box on there. i would start with what has been said. go buy a new distributor cap and rotor, spark plugs and a manual. Quote Link to comment
ggzilla Posted February 2, 2014 Report Share Posted February 2, 2014 Everybody likes to buy things. Instead inspect those parts and replace only if they are bad. The manual will help you inspect the parts, manuals have a great section on plug inspection. Quote Link to comment
thefridgeisempty Posted February 23, 2014 Author Report Share Posted February 23, 2014 Right, so took the easy road here and threw on a new cap/rotor/coil. Can't hurt, play it safe, start there I thought. Buttoned all back together, turn my key half on, lights, fuel pump check... Then as soon as I hit it to spark the engine I just get "click" and everything goes dark. If I disconnect and reconnect the battery, I get my accessories back but only until I try to engage again and "click" dark. I've double and triple checked my red and green off the coil. The fudge did I do???? Gotta get to the airport Monday morning! Quote Link to comment
thefridgeisempty Posted February 23, 2014 Author Report Share Posted February 23, 2014 Oh! And brand new wires/plugs, and it's a 79! Y'all are great. Quote Link to comment
ggzilla Posted February 23, 2014 Report Share Posted February 23, 2014 > Then as soon as I hit it to spark the engine I just get "click" and everything goes dark. Scrape the battery terminals and cable ends to bare shiny metal. This should be done every 12 months. Quote Link to comment
thefridgeisempty Posted March 7, 2014 Author Report Share Posted March 7, 2014 As for the dead click, missed a ground connection. Started and ran, same as before (maybe a little stronger, especially higher RPMs it seemed). Ready to shift attention to timing, which scares me but time to stop being a b@*%#... its the weekend. BUT, drove it as such for a couple of days, and lost [spark?] coming home, while accelerating to be specific. What makes it a squeeze more menacing to me (but gives me hope that its a simple problem) is that about 24 hours after it died, it fired up and ran just great! Got about 15 minutes out of it and crank no start ever since. To summarize: Backfiring New plugs/wires New distributor cap/coil/rotor Ran kind of better but generally that just meant bigger backfires, then died- crank no start, with one phantom start in the middle. The only other thing I can say that might be telling is that that stator and reluctor in the distributor are at least a 1/4" off contact resting- as close as I can get them with the distributor turned as far as it can go clockwise. I don't know why but something in my soul tells me that's off. Did I mention I was a novice? I leave this new question in this post because of the proximity of the new problem relative to the couple of part swaps I did for the original problem. My assumption is that they are related/the same problem. Thank you again, everybody. Nothing like Community. Quote Link to comment
thefridgeisempty Posted March 7, 2014 Author Report Share Posted March 7, 2014 Reading the manual a little more closely, maybe I've lost timing altogether? How do I turn the crankshaft? Quote Link to comment
banzai510(hainz) Posted March 7, 2014 Report Share Posted March 7, 2014 you got all weekend to watch this https://video.search.yahoo.com/video/play;_ylt=A2KIo9SJSBpT6FcAx.j7w8QF;_ylu=X3oDMTEwNm1iZGMyBHNlYwNzcgRzbGsDdmlkBHZ0aWQDVjE0OQRncG9zAzEw?p=hainz&vid=2046a71184f79aba37dcabcb9192656c&l=1%3A19%3A07&turl=http%3A%2F%2Fts1.mm.bing.net%2Fth%3Fid%3DVN.608043390653694260%26pid%3D15.1&rurl=http%3A%2F%2Fvimeo.com%2F19077890&tit=L+series+Head+Gasket+replacement&c=9&sigr=10pcg9tcr&sigt=110nkn4ss&age=0&&tt=b get some tools Turn crank shaft I use ny hands the turn the pulley when not in gear or use start to get close then use your hands. The only other thing I can say that might be telling is that that stator and reluctor in the distributor are at least a 1/4" off contact resting- as close as I can get them with the distributor turned as far as it can go clockwise. I don't know why but something in my soul tells me that's off. Did I mention I was a novice? Did I mention my vedio?????????? what year 620 I assume a 78-79? olddatsuns.com the tech section is good. i you get it to idle ck the timming and tell us what it is and if the dist is cranked all to one side or not Quote Link to comment
thefridgeisempty Posted March 7, 2014 Author Report Share Posted March 7, 2014 Thank you, I'm on it! Yes, a 79 Quote Link to comment
ggzilla Posted March 7, 2014 Report Share Posted March 7, 2014 Always start with the ignition timing. Don't touch the wires or carb until the timing is correct. 1 Quote Link to comment
datzenmike Posted March 7, 2014 Report Share Posted March 7, 2014 I don't understand the exhaust backfire. Watch Hainz's video. You need to check the valve lash. A tight exhaust valve could let the fire out and set off the fumes in the pipes. Quote Link to comment
Dillon scott Posted October 18, 2020 Report Share Posted October 18, 2020 What has everyone been doing to hook up dashpots making brackets not using it? Quote Link to comment
datzenmike Posted October 18, 2020 Report Share Posted October 18, 2020 Dash pots are used mostly with automatics and prevent and delay the sudden closing of the carburetor. Automatics are always in gear and there is a load on the engine. If you step on the gas but suddenly let, off this load can stall the engine. If you have a manual you don't need one. Quote Link to comment
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