Ok, here is my situation. I recently bought a 1991 240sx, auto, with 138k miles on it. I bought it cheap, though not running, with the hopes of fixing it and using it as a daily driver. This is the first real experience I've had working with cars at all.
The guy I bought it from told me it needed a new water pump, and had timing issues, resulting in the failure to start. I have since replaced the water pump, but don't really know where to go next. When I try to start the car, it cranks and sounds like its about to start up, but never does. Also, I noticed that the belt going from the engine to the AC compressor pulley and idler pulley was not there, but I assumed that would not prevent starting the engine up. Where should I look next to get this thing running? Thanks for any help.
Car almost start, but fails
welcome to NICO 
Ok with a car you dont know the history on ,you need to start with the basics. get a fuel pressure gauge and check your fuel pressure while cranking should be around 30 to 40 psi and hold within 10 psi when you stop cranking if it rapidly drops off when you stop cranking you probably have a leaking fuel injector. if it holds you know you have fuel supply. Quality of the fuel in it is important. how long has it been in the tank?? get fresh fuel if its been there more then 6 months. Now look for spark pull a plug wire off and put in an old plug in the wire boot, lay it on the valve cover and crank the engine. spark should jump the gap. if not try it with the coil wire if you got spark now you need to check your dist cap and rotor. This should get you started post back your test results and we can go from there.
Ok with a car you dont know the history on ,you need to start with the basics. get a fuel pressure gauge and check your fuel pressure while cranking should be around 30 to 40 psi and hold within 10 psi when you stop cranking if it rapidly drops off when you stop cranking you probably have a leaking fuel injector. if it holds you know you have fuel supply. Quality of the fuel in it is important. how long has it been in the tank?? get fresh fuel if its been there more then 6 months. Now look for spark pull a plug wire off and put in an old plug in the wire boot, lay it on the valve cover and crank the engine. spark should jump the gap. if not try it with the coil wire if you got spark now you need to check your dist cap and rotor. This should get you started post back your test results and we can go from there.
well, at first, it cranks like normal, and the shaking is what typically happens when an engine starts, the familiar roar like its about to start, but it doesnt. i'm pretty sure it has something to do with the timing or possibly timing chain, as that is what the previous owner told me. What do I need to check out to make sure the timing is right and what not?
BTW, i jsut replaced the spark plugs and I am getting a spark. The fuel in the tank has been in there for who knows how long though, but I wasnt sure if that wouldnt prevent it from starting all together.
BTW, i jsut replaced the spark plugs and I am getting a spark. The fuel in the tank has been in there for who knows how long though, but I wasnt sure if that wouldnt prevent it from starting all together.
ok, well i drained out all the old gas, filled it with fresh 93 octane, replaced the spark plugs, and am for sure getting a spark and gas, but i'm still not starting. my distributor lock bolt came off, and the distributor can turn freely, so i'm sure thats a problem, but no matter what i did with the distributor before, it wouldnt start. what needs to be done to fix this? thanks.
as long as the distributor is inserted and you know the rotor is not off any teeth the car should start if you set it in the middle of its travel on the bolt.
even though you drained the fuel out did you get the fuel out of the lines to the engine as well. it would take some time to clear those lines via cranking the engine. if thats all ok your at the point you know your spark plugs are firing, you know you have fuel pressure to the injectors. next step is to determine if the injectors are squirting into the cyl.
Did you ever try the carb clean into the intake air tube? if not try that and see if that makes it run for a couple seconds. have someone crank it over while holding the throttle about 1/4 while you spray carb clean into the intake tube be sure the air flow meter is hooked up or it wont fire. it needs to see a signal from that.
even though you drained the fuel out did you get the fuel out of the lines to the engine as well. it would take some time to clear those lines via cranking the engine. if thats all ok your at the point you know your spark plugs are firing, you know you have fuel pressure to the injectors. next step is to determine if the injectors are squirting into the cyl.
Did you ever try the carb clean into the intake air tube? if not try that and see if that makes it run for a couple seconds. have someone crank it over while holding the throttle about 1/4 while you spray carb clean into the intake tube be sure the air flow meter is hooked up or it wont fire. it needs to see a signal from that.
the carb clean will tell you if it is a lack of fuel problem. since you have spark. if its sparking at the right time it will run on the carb clean for a couple seconds.
if its timing you are going to have to do a mechanical timing check. pull the valve cover so you can see the align ment marks on the cams. then bring your crank pulley up to top dead center check the cams. if the marks are oppisite where they are suppose to be rotate the crank pulley around one revolution and look at the cams again if they are at their top dead center point and the crank is. now check your distributor rotor it should be pointing at #1 on your cap. if all match up your mechanical timing is ok.
if its timing you are going to have to do a mechanical timing check. pull the valve cover so you can see the align ment marks on the cams. then bring your crank pulley up to top dead center check the cams. if the marks are oppisite where they are suppose to be rotate the crank pulley around one revolution and look at the cams again if they are at their top dead center point and the crank is. now check your distributor rotor it should be pointing at #1 on your cap. if all match up your mechanical timing is ok.
ok, ive done a little more tinkering and this is what i have found. I removed the valve cover, and inspected the cams. I cranked the engine to TDC, and expected the cylinder 1 cams to be pointing apart, as this is what I heard somewhere. The left cam was perfectly parallel and pointing left, while the the right cam was pointing a little more up, about a half inch off from being straight with the other cam. I am assuming that this is a problem, but I don't know what the next step would be. Any ideas?
dont let it move to much or you could bend a valve. we use a special tool to hold it but you can also put a wrench on the hex part of the cam shaft behind the first bearing cap. I dont have a picture of how it goes but I belive the marks on the gers are not both in the same angle when at top dead center. I cant recall if the dowels are both straight up for top dead or not.
ok, the intake cam sprocket looks just like the picture, but the notch on the exhaust cam is a little more to the left than the picture. also the 1 cylinder cam lobes are pointing a little up as opposed to straight opposite the intake lobes. THe upper chain is also quite loose as well. I've been trying to get that cam bolt off but try as I might, it won't budge. What can I do?
Int.cam lobe tends to point to the valve cover gasket surface at about 45 min as on a clock and the ex. cam is about 15min after and pointing to the valve cover surface. The links between int. and ex. cam is 14 links.14 links ex cam and lower idler gear and 24 links from idler to int. cam. The chain should still have shinie or faded yellow links on it at timing points. Make sure eng. is tdc on compression stroke before setting valve timing. On that model if you have it down that far remove and discard both top chain tensioners as they are not needed as per the factory. You should consider doing a complete chain and gear replacement if the timing has jumped do to loose chains.
neekap,
I didn't mean to give the impression that the lobes would be exactly opposite of each other (180 degrees). It's a reference that they should be pointing away from each other. drjohn stated how they should look for you though. Counting the links is a surefire way of ensuring the marks are the correct distance from each other. I don't know what the problem is with getting the bolts off. I used a 2-foot breaker bar and a crescent wrench. If need be get a friend to hold the wrench for you as you crank the bolt off. Just count to three and you both start applying force in the appropriate directions. I would go with drjohn's recomendation of getting a new timing kit if the chain actually slipped. Also, the chain will seem loose once the tensioner is removed. When the tensioner is reapplied, crank it by hand a couple times and youll see the chain tighten up it. It's just how tensioner's work. Best of luck.
It should be like this.
I didn't mean to give the impression that the lobes would be exactly opposite of each other (180 degrees). It's a reference that they should be pointing away from each other. drjohn stated how they should look for you though. Counting the links is a surefire way of ensuring the marks are the correct distance from each other. I don't know what the problem is with getting the bolts off. I used a 2-foot breaker bar and a crescent wrench. If need be get a friend to hold the wrench for you as you crank the bolt off. Just count to three and you both start applying force in the appropriate directions. I would go with drjohn's recomendation of getting a new timing kit if the chain actually slipped. Also, the chain will seem loose once the tensioner is removed. When the tensioner is reapplied, crank it by hand a couple times and youll see the chain tighten up it. It's just how tensioner's work. Best of luck.
It should be like this.
Ok, even with the tensioner on, there is what seems to be an abnormal amount of chain slack. I'm not sure about the link counting thing, maybe clarify that for me. sorry for sounding so ignorant, this is the first work i've done on any car. Also, where are you getting those diagrams, they are really helpful. Thanks much,
No problem !! If you are going to replace the chain,tensioners and all the timing chain related parts their is no need to count links and so on. The new parts come with all the identifing marks. You will need to pull the pan down and the frt. timing cover off. The best manual for this job and all jobs is the factory service manual but they are pricey. Aftermarkets can leave you hanging for needed info. You might try f.a.q. board for step by step info.
neekap,If there seems an abnormal amount then just get the timing kit as drjohn said. Then you wont have to count links. We I say countinng links, I mean just that. You count each link on the chain. I don't know really how else to explain (sorry). I get the pictures from the factory service manual. It is in PDF format. I can setup an FTP if you want to grab it. Let me know.
yeah hey, that would be great to get that fsm, I would greatly enjoy that. contact me at neekap2 on aim or [email protected] thanks
after some additional fiddling, ive noticed that when cranking the engine by hand, the top chain is tight sometimes and then it gets fairly loose, then tightens again as I crank it. It just goes from being tight and loose as I crank it. Still trying to get that bolt off, I'll probably have to find myself a bigger wrench or something.