Okay so heres whats up. I just aqquired a 1990 240sx with a Redtop SR20DET in it. Mods are as follow:apexi 3" exhaust, 3" down pipe, 3" test pipe, SAFC, K&N, MBC. Car is at 7psi right now. I know I need a new valve cover gasket and sparkplug gaskets cuz its letting all kinds of oil drip and get into the spark plug wells. Other then that the car is acting like so, it idles high and really rough. like 1200 but goes up and down from 1100ish all the way to 1300ish. The car is also missing like crazy. Another problem I noticed that it is very hard to start. you have to crank it then give it some gas for it to fire up. I think I found the solution to that problem though. The bolt that holds the #1 coilpack down broke off inside so the coil pack isn't in all the way so have the time the car is probally running on 3 cylinders. The timing was also WAY off. It was set all the way to the advanced side(yikes ) Also I dont know how to hook a timing light up to this car. Its really weird. But I read the CAS should be turned a little bit clockwise from center. So I did that and its running a tad bit better. I still wanna figure out how to hook a timing light up to it so I can set it exactly to 15btdc. The motor also bogs down everyonce and awhile, im thinking this is because of the coilpack kicking in and going out? Also there is tons of oil leaked into the spark plug wells because ofthe gaskets. So tonight I ordered a Valve Cover gasket and Spark plug gasket from Courtesyparts.com Hopefully once I replace those and spray starter fluid to get all the grease and crap off the coil pack boots that the car will run alot better. Also tomorrow I am tapping out the broken bolt and getting a replacement. So hopefully after its all cleaned out and free of oil everywhere and its running on all 4cyl correctly it will run better, what do you guys think? And now tot he compression test. I did the compressin test(wrong I might add) and got a very consistent 120 all the way accross. Thats low though isn't it? But heres how I did the test. I just drove to a buddies house, turned the car off. sat there and talked for 15ish minutes, then went and did it. I just popped the hood, pulled the plug out, threaded the gauge on, cranked it, got the reading, then screwed the plug back in and move on. I've read that your supposed to pull the fuel pump fuse and have the car warm and have all the plugs out when your doing it? Would me re-doing it like that result in higher numbers? I think pulling all the plugs out would just make it easier to crank it without the car starting and I dont get the fuel pump fuse thing. Im just kinda worried about the lower numbers. Please someone tell me whats up with my motor. I dont understand them all being consistent as but a little low? Aren't they all usually good except for one that is drasticly lower? I am lost and ran out of ideas. The gaskets aren't coming for a few days and im just sitting here worried in the mean time. Please someone let me be at ease about the whole thing, any future help will be GREATLY appreciated.
PS. I also dont think there is a boost leak because when im driving the car it has very consistent boost and goes right to 7psi very smoothly.
Few SR problems, rough idle, hardstart, compression numbers?
Your panicing here bro.
Your miss and rough idle is most likely due to the oil in the plug wells causeing the car to arch out.
you did do the compression test wrong. car must be warmed up, all plugs must be out, the fuel pump fuse must be removed [this is to prevent fuel washing down the cyl,giving you a low reading]. the throttle must be held wide open during cranking to allow the maximum intake of air possible. you will get much better readings if you do it that way.
Your miss and rough idle is most likely due to the oil in the plug wells causeing the car to arch out.
you did do the compression test wrong. car must be warmed up, all plugs must be out, the fuel pump fuse must be removed [this is to prevent fuel washing down the cyl,giving you a low reading]. the throttle must be held wide open during cranking to allow the maximum intake of air possible. you will get much better readings if you do it that way.
yeah i know im freaking out here. I like can't sleep and stuff either. So you think after the valve cover gasket, and spark plug gaskets get here. And when I clean it out, and clean off the coil pack boots and put the #1 cylinder coil pack on right. And time it to 15btdc it should be running perfect?
when I re-do the compression test what should the numbers be reading? I know they had to be off cuz the motor was just bought from Zerolift Tuning in October and wasn't even put in till january and only driven a handful of times. And they say they compression and leak down test ALL their motors before selling them.
ahh..I hope your right man I've been so freaked out the past 2 days. And its been snowing out so its really hard to do anything. And I just wanna get this running right ASAP. And im just worried the since the timing was so advanced that it melted a piston or since my compression was low that maybe I have fried piston rings ahhh
so mine is only like 8 off. THANKS so much Nistech, you da man!! And nico is the place, screw Zilvia. Have any input on timing? I tried searching but I dont think I can do the method that consist of cutting an old plug wire and a coil pack, I dont have either of those laying around so im lost. Also I'd like to use a timing light if all possible instead of the removing the VC and setting the cams or whatever that was talkign about.
Re: (TheLocust)
If you have a standard inductive type timing light you dont need to go throught the wire and coil hassel. There is a loop on the harness near the back of the valve cover you can use.like in this picture.
yea sorry you had to endure that site, Its kinda hard to run with the big dogs when everyones sittin on the porch.TheLocust wrote: THANKS so much Nistech, you da man!! And nico is the place, screw Zilvia.
once again thanks, if all this works im gonna pay pal you a ten spot hahaha Im gonna check the gaps on the plugs tomorrow, and time it.. It still might run rough like you said because of the oil in the wells but hey im sure its gonna be better. My gaskets should be coming Thursday, thats my day off so it will be perfect. I'll clean everything, tap that bolt out. installt the gaskets, make sure to get all the oil off the coil pack boots, Re-check timing, gap plugs to 29, make sure the #1 coil pack is actually bolted down lol and see what happens. If that doesn't work then I do not know what is wrong.. if that happens then I may leave the Nissan family and I dont wanna do that. I love RWD, I love Vrrm Pssh, I love the ****ing car but I will be OUT of ideas if all that fails and I really dont feel like putting piston rings in this thing..so it'll be traded off for some FWD, No torque, N/a crapness
Im kinda nervous about that....I just hope its because of me doing it wrong........ my fuel pump has an on/off switch wired in. So I should just start the car.. let it idle for a few minutes, then flip the killswitch and let the car die. Then pull All the plugs out. thread the gauge on, hold my foot on the gas and let it crank untill the needle goes up 4 times or roughly 5 seconds? And you promise that i'll get higher numbers
I understand, I trust you over them actually as you seem to know whats up when it comes to SR's and 240's in general. Which is why I came here for help instead of relying on them. Once again thanks for all your help. As soon as I get a day off school and work and am not busy as can be then im gonna do another compression test and hope for the best. Also someone on Zilvia said that since the 10mm bol that holds the coil pack down broke off that my coil pack may be fried now? Is this true? If so how would it be acting once I get everything put back together if it did infact have a fried coil pack on the #1 cylinder, im guessing it'd just be like it running on 3 cylinders correct?
Thank you for your trust, but for the record on this issue it doesnt really matter what engine it is. The test is a basic test performed on all engines.
They are wrong about the bolt. The coil does not rely on an external ground. That bolt is mearly to hold it in place. Once you extract the old and rebolt it it will be fine as long as something else wasent already wrong with the coil. Further more as long as the coil was on the plug it wouldnt of effected the cars drivability unless it popped off. The bolt is only to keep it from coming out of the whole.
They are wrong about the bolt. The coil does not rely on an external ground. That bolt is mearly to hold it in place. Once you extract the old and rebolt it it will be fine as long as something else wasent already wrong with the coil. Further more as long as the coil was on the plug it wouldnt of effected the cars drivability unless it popped off. The bolt is only to keep it from coming out of the whole.
Alright, where you at NISTECH? I finally found the time to screw with the car some more. I cleaned all the oil out, changed the oil, changed all the gaskets under the valve cover. Drilled the bolt that was snapped out, cleaned off the coil packs and got everything back together. The car is timed perfect. Alligned it like it says on Heavythrottle then checked with a timing light on the black and yellow wire. It was perfect. Went to start it..nothing then I realized that im dumb and my fuel pump switch was off. Turned it on. Started up awesome. car has a way smoother idle. Its at about 1100 rpm but doesn't really sound high or anything. And I took the car out and everything is fine untill you get up to the point where your about to shift(higher RPM range) 3000ish roughly and the car misses and pops A LOT. Runs fine untill you get to that point. Once you shift it is fine untill you get up to that spot again. Does this in everygear. it is not driveable its so bad right now. The only thing I can think it is is the plugs? Am I right? because the car ran better then this before. it had a rough idle and was hard to start because the #1 coil pack was 'loose' and the timing was way off. but once you started going it was fine. So I went to autozone and asked for the NGK BKR7ES11(I think, something like that dont know for sure off the top of my head) and they didn't have them. So I had the old plugs that were in the motor when I got it. They are like Denso I believe. And were gapped to .42. When I bought the new Denso's(same exact kind, because they didn't have the NGK's) the plugs came gapped to close to .42. I always thought for the most part plugs came gapped pretty close to what they were supposed to be. But I said eh whatever and gapped them to .29 and put them in(this was when I was reassembling it, and thats what plugs/gap it was at when it was doing the mis/pop thing when your up about to shift) By that time it was dark so I called it a night. Im thinking its the wrong plugs and whoever had the motor before me was retarded or something? So tomorrow im gonna call around and find the NGK BKR7's somewhere and gap them to .29. Do you think this will solve the problem? I didn't really change anything else aside from correct the timing. And the idle and everything is better so I dont see what could make it worse besides the plugs. thanks for the future help
No plugs wont cause what your experiancing, If the idle is better and the early accel is ok, I am thinking a connection is dropping out somewhere like the maf or your loosing fuel pressure.
At this point T in a fuel gauge between your filter and the injector rail and position it so you can see it while your driving. Whatch the gauge as you approach the point where it starts to cut out and pop see if your pressure drops off substantially. If it does you may have a week fuel pump or a fuel pressure reg staying open. [When you punch the throttle from idle the fuel pressure reg should close off the return and your pressure should jump up about 5 to 6 psi.]
If the pressure seems ok then take a look at your maf voltages see if one is droping out on accel.
It really sounds like lack of fuel here is causeing the problem
At this point T in a fuel gauge between your filter and the injector rail and position it so you can see it while your driving. Whatch the gauge as you approach the point where it starts to cut out and pop see if your pressure drops off substantially. If it does you may have a week fuel pump or a fuel pressure reg staying open. [When you punch the throttle from idle the fuel pressure reg should close off the return and your pressure should jump up about 5 to 6 psi.]
If the pressure seems ok then take a look at your maf voltages see if one is droping out on accel.
It really sounds like lack of fuel here is causeing the problem
could it be lack of fuel, Or too much fuel and not enough of it getting burned? The car still puts out some(not much) but a little bit of black smoke. I have a spare SOHC MAFS laying in my shed. I was planning on buying a Walbro 255 in the very near future. Also I Was thinking maybe the fuel filter is clogged or something? You suggest just running to Autozone and picking up a Z32 fuel filter?
no, I have to find a fuel gauge somewhere... I replaced the MAFS with a SOHC KA one. That did nothing. So I guess tomorrow im gonna look around and try and find a fuel gauge somewhere. Also I pulled one of the plugs out and it was black as hell. My car is still running really rich and I have NO idea why. It has stock inj, stock fuel pump, stock everything. I took off the SAFC even to make sure that wasn't messing with it. Im thinking the way its running like this is just because the plugs were fouled out? Tomorrow im picking up the plugs I ordered(had to order NGK BKR7ES11's because no place around here had them. Right now the car has some cheap denso plugs that came pregapped to .42 so im GUESSING that those aren't the right plugs for my car. What could be causing the car to run so rich? Im just trying to figure out all possibilities for if tomorrow I hook up a fuel pressue gauge and that all checks out.
the coolant temp sensor can also cause it to run rich if it thinks its cold. It would not cause the car to caut out as you say its doing. also the o2 sensor but it wont cause it to cut out like your experiancing either. Maf and fuel pressure are the only components i can think of and possible restricted exhaust, since you have a turbo it could have a relation to restricted exhaust.
I have a 3" dp, 3" Catco free flow cat, 3" apex'i N1. I dont really think its restricted exhaust. And I know whatever is making it run rich isnt causing it to cut out and pop/misfire. But its causing me to foul out plugs really fast. and once I get these new plugs in that I had to order because no place around here stocks them, I really dont want them to get fouled again. Im really starting to think the plugs are fouled out and that is causing it to pop and all that jazz. Are you sure its not the plugs? It can't be the MAFS because I replaced that today. Im checking fuel pressure tomorrow if I can find a gauge anywhere. Im thinking it may be the FPR. Im stupid in this field, the FPR is located in the tank by the fuel pump correct? Im kind of hoping its not SR specific so I can find one easy if that is the problem. You think an old worn clogged fuel filter could be the perpetrator here? It runs fine in 1st gear till I get on it and get ready to shift then it just FALLS on its face and starts acting up. So its like when the car is needing more fuel(me accelerating harder) is when it starts acting up. Like it needs more fuel but either something isn't letting it(fuel filter, or either the FPR or pump like you said) or its getting to much fuel and not enough spark(because it IS running rich, and im starting to think the plugs in the car aren't the right ones) I just want this thing to run right
The FPR is on the fuel rail the injectors are connected to. This is why I asked you to test the fuel pressure when it acts up, to see if it is lack of fuel pressure or not. Yes a plugged fuel filter can give you a lack of fuel pressure. Denso are not the factory plugs, but I have not experianced any problems with having Denso in nissans as I believe NGK and Denso are made by the same company. not 100% sure on that though.