dasz33 Posted May 10, 2006 Share Posted May 10, 2006 Hey all, A friend of mine with a 240sx and red top SR20 needs a hand. Ive done all the trouble shooting I can, so any questions comments help would be appreciated. My recommendation to him is to sell the car and give me the motor for my '71Z. But thats not working out so far. Below is a copy of a post he made and a link to it on zilvia.net. Let me know what you think. I think the free beer would apply to you all too, if youre in the Parker CO area. http://www.zilvia.net/f/showthread.php?t=109081 SR20 Won't Start I haven't posted on here in a long time because I thought all my quirk were finally worked out, but apparently not. So last summer/fall my 240sx with a redtop SR20 was running fine. Never ridden in another SR powered car so I am not sure it was running smoothly, but it felt and sounded plenty strong. I went to start it this weekend (after it had been sitting for 5+ months in my garage) and nothing. It doesnt even try to turn over. The starter sounds like it is doing its thing, but it never even tries to turn over. From what I can tell it has all the necessary components to run, but it doesnt. -Air - Not sure how to test this...but I disconnected the pipe to the throttle body at one point (for testing), and it still didnt start, so if it is an air problem, it is not in the Intake or IC piping. -Fuel - Confirmed fuel is making it to the fuel rail (disconnected the fuel line at the rail and put it in a bucket as I turned it over). Also confirmed that the injectors are atleast clicking, which leads me to believe they are spraying. -Spark - Hooked plug wires up to a spare plug I had and they were able to arch onto the valvue cover. Spark seemed a little less then normal, but I tested with a spare/old plug. I am by no means a mechanic so I really don't know what else to test at this point. Like I said, it worked fine 5 or so months ago when I parked it, but now it doesn't. Any ideas? BTW...if anyone in the Parker, CO area wants to stop by and take a look...I will supply the beers. Quote Link to comment Share on other sites More sharing options...
Hugh Posted May 10, 2006 Share Posted May 10, 2006 Thats pretty weird... he's got fuel, clicking injectors, firing spark plugs... but no cylinders firing? OK, the MAF could need to be cleaned or replaced. I've seen that happen before. If his car sat for 5 months, the MAF could've easily corroded to the point where it doesn't work now. Remove the MAF, spray the element with brake parts cleaner or carb cleaner. Brake parts cleaner is nice for a MAF because it dries out quickly. This problem puzzled us for hours one day until we swapped MAF's with a friend's SR and it fired right up. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted May 10, 2006 Share Posted May 10, 2006 Sounds plausable. This is from the 240sx ka24de manual, which Might work on the SR. Set crank to TDC, mark on the distributor the TDC point (not testing for spark, testing the injections circuit). Unmount the dizzy. With the ignition set to ON but not cranked, rotate the dizzy shaft, you should hear each on of the injectors click. The injectors may be fine, but there might something along the wires that maybe wrong, maybe even the ECCS (ECU). Only way to know with the MAF is to replace ans see. Quote Link to comment Share on other sites More sharing options...
Hugh Posted May 10, 2006 Share Posted May 10, 2006 It's direct ignition though. For the ingnition to be firing, the CAS signal has to get to the ECU, and then from the ECU back to the ignitor. Thats what makes me speculate the ECU is ok. If you had someone else's handy, its worth swapping just to see. But its also less likely for an ECU to corrode from sitting. Quote Link to comment Share on other sites More sharing options...
Guest shaggy240sx Posted May 10, 2006 Share Posted May 10, 2006 But would the dirty MAF prevent the car from even trying to fire? It turns over, but it never even sputters like it is almost starting...it just turns over and nothing else happens. So clean the MAF, the Filter, and the connectors for the MAF plug? The KA MAF is supposed to be the same, just a different plug...I think I still have them sitting around...I could try that out too I guess. Quote Link to comment Share on other sites More sharing options...
Guest shaggy240sx Posted May 10, 2006 Share Posted May 10, 2006 BTW...I am on my second ECU and second Harness already. Both were bad when shipped. I know the old ECU kind of works (doesnt tell Injector 1 to spray...ever)...I suppose that is something else I could try to narrow it down a little. Quote Link to comment Share on other sites More sharing options...
Lewis Maudlin Posted May 10, 2006 Share Posted May 10, 2006 Mine didn't have spark. I thought it was the ecu and it turned out that the CAS was not properly installed. Also, I had to get a new starter. The starter would not crank hard enough to start the engine. Are you sure your starter is working properly? Quote Link to comment Share on other sites More sharing options...
Guest shaggy240sx Posted May 10, 2006 Share Posted May 10, 2006 Starter sounds like it is trying just as hard as normal. I suppose I could try push starting it, but if that doesnt work it would be a PITA to get it back into the garage. I will check the CAS too...I had an extra one of those too...but I might have trashed that (have I mentioned that I am on #2 for most components). Quote Link to comment Share on other sites More sharing options...
AK-Z Posted May 11, 2006 Share Posted May 11, 2006 Yeah check the CAS to see if oil some how leaked inside. Happend with the KA that I have. even says to check that in the service manual. Does it flash an error code? Does JDM engines even have OBD? Quote Link to comment Share on other sites More sharing options...
dasz33 Posted May 11, 2006 Author Share Posted May 11, 2006 Shaggy240sx is my friend I was talking about, looks like he signed himself up on our hybridZ. Just wanted to say thanks for your help, and keep the ideas coming. The sooner he gets his car back on the street, the sooner he might wreck it and then I can have the motor ! Quote Link to comment Share on other sites More sharing options...
Hugh Posted May 11, 2006 Share Posted May 11, 2006 Umm... the 89-90 KA is supposed to have a MAF that puts out the same signal. It's not ideal for performance, but so long as you wire it correctly you would know if that fixed it. If you wire it wrong, you will probably burn up the ECU, so be careful with that. Anyway, yes. I've seen a car not fire because of a bad maf signal. Try unplugging the MAF altogether and starting it. This should put the ECU in limp mode, and allow it to run up to about 1500rpm. I once idled my car for a long time with no MAF hooked up. (to keep power brakes while being towed after twisting the output shaft on the transmission off) Quote Link to comment Share on other sites More sharing options...
Guest shaggy240sx Posted May 11, 2006 Share Posted May 11, 2006 Wires on the KA24E are the same color as the SR MAF...so I would imagine the wiring should just be a matter of matching colors, right (black to black, black/white to black/white, and white to white)? So no MAF puts car in limp mode, but bad/dead MAF puts it in paper weight mode? Seems strange to me, but is worth a shot. Thanks for all the help guys. I really appreciate it and will keep you posted with the results. Quote Link to comment Share on other sites More sharing options...
Hugh Posted May 11, 2006 Share Posted May 11, 2006 Hey... electronics are funky like that. One thing might act differently in your car than the next guy's.. It's worth a shot to unplug the MAF real quick and see what happens. Have you pulled the plugs to look at them yet? Make sure you're not flooding the motor and then trying to change things to get it started. You might find the fix, but its flooded so it doesn't start. Obviously you should smell some fuel in the exhaust (especially if you have no cat on the car) and that would tell you its flooding. To flush out the fuel, I usually pull the fuel pump fuse and run the car til it dies. (or just turn it over for a few seconds in your case... so long as the plugs can fire, they should clean themselves up) Quote Link to comment Share on other sites More sharing options...
Guest shaggy240sx Posted May 12, 2006 Share Posted May 12, 2006 Hmm...so apparently the connection to the ECU wants to be about 1/2 turn loose. Once I loosened the bolt a little it fired up...only problem is I was messing with the CAS before that...so now I have to fix my timing. But at least it starts now. I hate electronics. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted May 12, 2006 Share Posted May 12, 2006 the center one on the ECU connector? That should be the ground connection to the ECU. See if cleaning it will make it work with the bolt screwed in. I don't think you want to drive around with a ecu connector too loose. Quote Link to comment Share on other sites More sharing options...
Guest shaggy240sx Posted May 12, 2006 Share Posted May 12, 2006 Yeah...thats the bolt I am talking about. Its not really loose at all, and it is still beyond hand tight, just not quite all the way to the point that it no longer spins is all. I will probably try cleaning it in the next day or two. Thanks for all the suggestions guys. I appreciate it. Quote Link to comment Share on other sites More sharing options...
Hugh Posted May 12, 2006 Share Posted May 12, 2006 Wow, that would be a tough problem to diagnose. Definitely falls into the "visual inspection" stages of the troubleshooting. Heh heh Glad you got it running. If you need timing help, use the service manual. I've got them on my site in the tech section for download. ( http://www.zeroyon.com ) Quote Link to comment Share on other sites More sharing options...
AK-Z Posted May 12, 2006 Share Posted May 12, 2006 Haha. thats where I got my service manuals for my KA. I found that sight before I found this site. Thats where I first heard of stony and first time I've seen a S30 with a RB motor (long time ago). I would of like to say that that would of been the first thing that I would of checked, but honestly I would of check that last. Thinking about it, if you checked that first in any engine problem, you would isolate about 1/3 of your electrical problems. Quote Link to comment Share on other sites More sharing options...
Guest shaggy240sx Posted May 12, 2006 Share Posted May 12, 2006 Found a FSM on another site. Got it dialed in good enough for now. The ECU thing...I really just got lucky. I would have never thought to not tighten it all the way down. I figured you would want it as tight as it would go without breaking. I got lucky when I was putting my old ECU in...I left it a little loose and it almost started (old ECU is crap). Took me 4 or 5 times of switching the ECU's out back and forth with no success before I got the idea to leave it a little loose. Not really sure an ECU connection that is too tight would be something that anyone would intentionally check. The connection was snug, so it would pass the visual inspection. I just dont know sometimes. I hate electronincs. Thanks again. Quote Link to comment Share on other sites More sharing options...
Guest s13redtop Posted September 1, 2007 Share Posted September 1, 2007 hello, i was hoping someone would have some advice for me. my sr20 front clip will not fire. the motor is still installed in the clip. i have hooked up a fuel pump to the rail, and i cant seem to get fuel. when i checked the plugs, they wer dry. the motor also has poor spark. while turnig it over with the front plug touching a intake manifold bolt, i cant see any spark. but when the key is shut off i will see a quick spark. i cant understand why i get a spark after the key is off, if any one can help, please do. Quote Link to comment Share on other sites More sharing options...
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