pshepard327ci Posted November 4, 2004 Share Posted November 4, 2004 Hey all, i got another question for you guys. i recently swapped a 83' l28et into my 240. i got all the wiring done i believe everything is on i believe. i get spark and the injectors click. i tried starting in about a month ago and it ran for about 6-8 seconds. i was told to check fuel pressure i put on a guage and it was at like 60psi. so i checked the fpr and it was bad so i got a new stock unit, installed and pressure stays at 36 or so. but now it doesnt run at all. I dont have some things hooked up im just trying to get it to idle that way i know everything works so i can permantly hookup everything. why would it run at such a high pressure but not at correct pressure. After it wouldnt start when i corrected the pressure i pulled the plugs and they were dirty, real dirty, i cleaned them up to new finish with some contact cleaner. still nothing. but my battery is barely able to turn the starter. Any idea on what might keep it from starting. the only things that arent hooked up are the oil pressure sending unit and the Ox-sensor, that i know off. Would the battery being so low not allow it to run? any help would be awsome. thanks for your time. Peter Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 5, 2004 Share Posted November 5, 2004 Yes a low battery could cause the car not to run, the EFI system needs a certain voltage to operate properly. However, I must say I've had times where the battery was so low the starter barely turned, and yet I was still able to start it. Still... the easiest, first thing you could and should check, would be that, charge the battery (stores like Auto Zone will do this for free) or get a jump start and see what happens. The O2 and oil pressure unit being disconnected would not cause the car not to be able to start. So... barring the low battery, you've got one clue that your car seemed to want to run when it was running more rich. L28ET's do like to run very rich at start up... so maybe something isn't working there causing you not to get your cold start enrichment. Another clue, the car ran, but then stopped after a few seconds. To me this hints at something electrical... I had gremlins like this for a long time... and I can't tell you they aren't usually a pain in the butt to figure out. I had issues with both my ignition module, and with a bad wire connecting to the EFI relay, that were causing the car to run and then suddenly cut out like that. Now that you can't even get the car started, it's just going to be that much harder to diagnose... I think the only other solution at that point is to get a multimeter and start checking wires. Quote Link to comment Share on other sites More sharing options...
Guest 2slo4u Posted November 5, 2004 Share Posted November 5, 2004 Plug in the oil pressure sensor. It will keep the fuel pump from staying on if it is disconnected. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 6, 2004 Share Posted November 6, 2004 Plug in the oil pressure sensor. It will keep the fuel pump from staying on if it is disconnected. Not true, I have a autometer mechanical oil pressure gauge and NO electrical connections going to oil pressure switches. The fuel pump on a L28et is controlled by the ECU via a relay. The ECU can tell if the engine is running by the airflow reading. If the engine is not running and you try to start it the fuel pump should to into a "priming mode" as soon as you turn the key to the "on" position. The priming mode will only last a few seconds and the fuel pump will automatically shut off unless ECU gets a airflow reading suggesting that the engine is running. Also the priming mode is also like a "computer boot up" Meaning if the fuel pump runs when the key is turned to on, then that means that computer is likely functioning properly. If you don't hear the fuel pump turn on then the ECU is either fried or something isn't connected properly. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 6, 2004 Share Posted November 6, 2004 Sorry, my last post didn't really answer any of the original questions first, the engine will run just fine without the O2 sensor second, do yourself a favor and get a good charged battery in there because if you can't turn the engine over good and strong it will be impossible to say what the problem really is. third, you said that you have spark and the injectors are clicking so I'm gonna "assume" that it is a fuel problem.. Maybe the injectors are dirty causing a poor fuel spray, or flooding the engine. In which case it may yet start (even if it runs crappy) providing you can get it turning over long enough. If you can get it turning over really good and it still won't start and you think it is flooded, take out ALL of the plugs and turn the engine over (this will clear it out) Then put the plugs back in (or better yet new plugs) and hopefully it will start. If you still have problems you might want to take the injectors out and test them, if this engine came out of a junkyard or had been sitting a long time.. the injectors could be messed up from sitting. Quote Link to comment Share on other sites More sharing options...
pshepard327ci Posted November 6, 2004 Author Share Posted November 6, 2004 ok, i will get that battery charged immediatly, about the injectors they are the shearco ones i purchased from a guy on this board, there was some dirty fuel in the tank that i found out about after installing them and running. That was when it was running super rich for a couple seconds. I really dont wanna have to take that rail off again, but i guess thats the next step after battery and checing all connection over. thanks for all the help i really appreciate it. if anyone else has any ideas throw them my way!! peter Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 6, 2004 Share Posted November 6, 2004 Ok this may be a stupid question but if you bought injectors from a guy off the board, what cc's are the injectors? Unless you are running some sort of modified ECU or AFM anything but the stock 260cc injectors will flood the engine for sure! Quote Link to comment Share on other sites More sharing options...
pshepard327ci Posted November 7, 2004 Author Share Posted November 7, 2004 they are the stock injectors for the '83 280zxt, but not a stupid question, ive made so many mistakes on this project , nothing is stupid. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 7, 2004 Share Posted November 7, 2004 my fuel pump doesn't ever go into 'priming mode' if I turn to key to the ON position it will run forever. Never did figure this out.... Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 7, 2004 Share Posted November 7, 2004 my fuel pump doesn't ever go into 'priming mode' if I turn to key to the ON position it will run forever. Never did figure this out.... Most likely your fuel pump relay is not hooked up correctly. It is a good idea to get it working properly as it is a safety issue. You see, if your fuel pump is allowed to run forever even if the engine is not running then imagine what could happen in a a car accident and the fuel line is broken an you've hit your head and don't realize that gas is being pumped all over the road. I'm sure a car would fail a government safety inspection and be taken off the road for reason like that. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 7, 2004 Share Posted November 7, 2004 I'd fix it trust me I dont like it that way either... but being as I didn't wire it in I have no idea how it's set up. It's been like that ever since the turbo swap. Even afterwards Tim240z wired in a new relay and hooked my pump up to the starter instead, and it still did the same thing. The only relay I know about other than the one he installed, is one green capped relay out of the ZXT donor car, with four wires going to it? Is this where I would need to look? Do I just wire it differently or what? Or is it possibly bad and that's why it doesn't shut off? Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 7, 2004 Share Posted November 7, 2004 I suppose it is possible that your fuel pump relay is "locked" up in the on position but I doubt it, more likely that it is wired up wrong. There are many ways to wire up a fuel pump relay on a L28et, it depends on your setup... A: are you using the module to reduce voltage to the fuel pump at idle? B: are you using a L28et ECU or the Z31/MAF upgrade? Using the module is a little more complicated and seeing that I never did get the module from my donor car I decided to do without it (my pump isn't so loud that it was ever a issue for me anyway) Nissan relays generally have 5 terminals but you only need to use 4 for the FPR. Two terminals control the coil or "triggering" part of the relay. one of these pins goes to the ECU (the "LR" wire on the 6 terminal plug of the injection harness near the knock sensor) and the other "trigger terminal" goes to ground when using a L28et ECU (+power source on a Z31 ECU) NOTE: If you hook up power (+ and -) to these two terminals you will hear a definate "click" from the relay. Now the other two terminals are the power circuit of the fuel pump and will only have continuity when the there is a signal coming from the ECU One terminal should be connected to 12v+ (best choice is directly to the battery, but make sure to use a fuse) The other terminal goes to the + terminal of the fuel pump. The - terminal of the fuel pump is best hooked up directly to the - battery terminal Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 7, 2004 Share Posted November 7, 2004 No module for reducing idle voltage, as far as I know. Running L28ET stock '82 ECU. The green relay is hooked up as you say, it's got five spades but only four have a wire on them. So I have to trace the wires from the relay and see where they go... Things are a little different now as I said Tim wired in a new relay at the rear of the car and wired the pump directly to where the positive battery cable bolts to the starter. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 7, 2004 Share Posted November 7, 2004 The green relay is hooked up as you say' date=' it's got five spades but only four have a wire on them. So I have to trace the wires from the relay and see where they go... quote'] If your fuel pump is wired to the battery cable at the starter then it has a good strong source, and must have a relay hooked up somewhere or it would never stop running at all (even if you pulled the key out) So it sounds to me like the fuel pump relay is wired up fine with the exception of what is being used as a trigger. Sounds to me like there is just a +ignition source being used as a trigger instead of the ECU. You should also know that there is another relay on the injection harness mounted around the same area (the EFI relay) Make sure you don't just start messing with that. If I remember right the EFI relay has a connector right on the main injection harness, where the FP relay is connected further down the line (on the other end of the 6pin connector I was talking about earlier) The LR wire (blue with red stripe") is the FP relay's "trigger and it is pin 16 at the ECU. So if you think you found the right wire, unplug the ECU and use a ohm meter to check for continuity to pin16. Then you will know for sure. My apologies to pshepard for the highjacking of this thread. Quote Link to comment Share on other sites More sharing options...
Guest znow white Posted November 8, 2004 Share Posted November 8, 2004 check your timing, i would also check what zx fuel inj. you have green are NA and Brown are TURBO i believe. also stock turbo injectors says JECS or something like that. I would clean all your electrical connection from ecu, relays, sensors, fuel injector plugs all of that! these cars have major electrical gremlins. Blue on zcar has a nice website to clean electrical connections. also empty and clean fuel tank check fuel lines fuel filter. just some regular checks. http://www.atlanticz.ca/zclub/techtips/index.html very informative website Quote Link to comment Share on other sites More sharing options...
pshepard327ci Posted November 11, 2004 Author Share Posted November 11, 2004 ok, so i got the battery charged and it wants to start just doesnt. I have no clue why it doesnt start, but im thinking some dumb wire or something not hooked up, maybe a ground or something. on a side note i was beginning to hear some wierd scraping kind of noise right after i tried to start it. i was thinking oil so for the hell of it i pulled off the oil line to turbo and no oil flowing while cranking... me thinks no good , so i pull the valve cover off and same thing no fresh oil being circulated. There is 5 qts of oil in the pan, and the dip stick reads that as well, how much pain am i going to deal with fixing pump. im about to put the l24 back in because i could drive the car and it was fun, this is not drivable and far from fun. any ideas about oil problem. Any houston area Z guys want some free beer in exchange for free labor , thanks peter Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 11, 2004 Share Posted November 11, 2004 im about to put the l24 back in because i could drive the car and it was fun' date=' this is not drivable and far from fun.[/quote'] That was my daily saying for a while... I got stiffed pretty bad on my L28ET motor which had SUPPOSEDLY been rebuilt recently... I know that pain all too well. I can't say I've ever heard of an oil pump failing so dramatically that it just ceased pumping altogether, I've never personally had a problem with a stock oil pump on four motors I've had now, so I would guess it is a clog somewhere. The simplest quickest place to check is the oil filter... if you are unsure or dont know it's age and condition, swap it out. I've seen the oil pickup in the crankcase get clogged once on a really old tired motor... it's a short days work to pull the pan and inspect. Otherwise I dont think there's an easy thing to check, since the rest of the routing is all internal to the block. That scraping noise.... *cringe* that's really not good. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted November 11, 2004 Share Posted November 11, 2004 The L28et that you have, did it come from a manual or auto car? If it came from a auto it would have come with a engine oil cooler from the factory. I had to get some oil cooler lines custom made as the zx ones did not work in my Z. Did you by any chance just plug those holes off thinking that it would oil normally? I thought of doing that to avoid all the trouble with the oil lines (I'm in a cold climate anyway) but I wasn't sure how the oil direction/flow worked so I decided not to mess with it and make sure I had the cooler hooked up. Just a thought.. As for the oil pump failing Bastaad is right, I never heard of a failure on a L engine either. In fact L engines are VERY tough!! Could it be that the grinding was the starter or something else? It is possible that you won't get any noticeable oil pressure until the engine actually starts and turns at 1000 rpms or so.. Especially if the engine has been sitting a long time. As for starting, does it fire or buck/kick at all? or is it simply turning over like a log on a river. Do you still have spark? Get one of those little injector test lights and see if you are getting a injector pulse. Was your engine in unknown condition? maybe even a compression test would be in order. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 11, 2004 Share Posted November 11, 2004 If he's turning it over for more than a few seconds, he should get at least some oil coming from the turbo supply line, and some fresh oil in the head. When I'm adjusting the valves on my car... this is with the motor cold, and I use the starter to kick the motor over and rotate the cam, some oil comes out of the cams oiling holes almost immediately. Quote Link to comment Share on other sites More sharing options...
pshepard327ci Posted November 11, 2004 Author Share Posted November 11, 2004 There is no oil what so ever coming out of the oil hole on camshaft, i hope grayzee is right because i dont want to have to keep replacing parts. the motor came out of a manual i believe, when i put the flywheel on i had to spacer on it or anything. and that scraping noise only happens after i stop cranking or after it runs for half second then stops, might be something else but it still scares me. Quote Link to comment Share on other sites More sharing options...
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