needing help with an engine miss

[slammed04ram]

Alright first off my brother just bought a 95 240sx 5 spd with 154K on it..Has a dead miss on the number 2 cylinder..put in new plugs, wires etc..getting plenty of fire through the wire to the plug but the cylinder just doesnt wanna fire..(idles the same with the plug wire on or off) I took the oil cap off and am getting blow by out of the cap hole..not for sure where to go from here.should i just go ahead and call it a valve problem or??.Told him id sell him my 240 for the engine and plenty of parts lol ...but he wants to try and fix this one first.Any help on this guys would be greatly appreciated..thanks

[S13 240SX]

the miss can be a crappy fuel injector for cylinder 2... thats just my guess..... But ,

what your doing with taking the oil cap off checking for blow-by.. I couldn't tell ya on that one cuz i'm not sure on that.. How can you fill me in on that trick by checking that?..

[InsanityInc]

Alright first off my brother just bought a 95 240sx 5 spd with 154K on it..Has a dead miss on the number 2 cylinder..put in new plugs, wires etc..getting plenty of fire through the wire to the plug but the cylinder just doesnt wanna fire..(idles the same with the plug wire on or off) I took the oil cap off and am getting blow by out of the cap hole..not for sure where to go from here.should i just go ahead and call it a valve problem or??.Told him id sell him my 240 for the engine and plenty of parts lol ...but he wants to try and fix this one first.Any help on this guys would be greatly appreciated..thanks

Put one end of a screwdriver on your ear and the other on your #2 injector while the car is running. You should hear a pretty loud clicking noise. If you don't, that injector is busted. Listen to your other injectors for a reference on how it should sound.

[S13 240SX]

yeah it could be his injectors... but yet i want someone to explain to me that trick he done by taking the oil cap off to dected for blow-by? Only reason why i wanna know is because I don't know that trick

[InsanityInc]

yeah it could be his injectors... but yet i want someone to explain to me that trick he done by taking the oil cap off to dected for blow-by? Only reason why i wanna know is because I don't know that trick

Taking your oil cap off and feeling for air is done to check for leaking gases through your crankcase, since your PCV system sends crankcase gases into the valve cover. You usually do it when you're doing a leakdown test, not when the engine is running.

[S13 240SX]

uh ohhh.. so if any kinda air comes out like that... slow air, fast air, little air, or a lot air, then the motor could be going???? **** cuz i took my oil cap the other day to get a closer and better hear for my valves and it was blowing out some air... : (

[InsanityInc]

uh ohhh.. so if any kinda air comes out like that... slow air, fast air, little air, or a lot air, then the motor could be going???? **** cuz i took my oil cap the other day to get a closer and better hear for my valves and it was blowing out some air... : (

It will always blow out some air, as all engines have some blowby. Also, doing it while the engine is running could be totally misleading. You have camshafts whirling around under there which will move air.

[slammed04ram]

thanks for the quick replys guys..i thought the same thing..i switched out the number 3 injector with the number two..(since i knew number three was firing) still the same problem.maybe a bad connection to the injector or something..i dunno im gonna check alittle more into this tommorrow for sure..

[InsanityInc]

thanks for the quick replys guys..i thought the same thing..i switched out the number 3 injector with the number two..(since i knew number three was firing) still the same problem.maybe a bad connection to the injector or something..i dunno im gonna check alittle more into this tommorrow for sure..

You can test for a bad connection by using what's called a noid light. If I recall, the GM one fits in the injector connectors. However, the bad news is that if the noid light doesn't blink, the problem is probably the injector driver in your ECU.

[S13 240SX]

It will always blow out some air, as all engines have some blowby. Also, doing it while the engine is running could be totally misleading. You have camshafts whirling around under there which will move air.

pshhhhh then I"m alright then I think..

[InsanityInc]

pshhhhh then I"m alright then I think..

Just do a compression or leakdown test if you want to know for sure.

[S13 240SX]

i did a compression test a few days ago....and it was this...cylinder 1. 160cylinder 2. 150cylinder 3. 160cylinder 4. 155

[InsanityInc]

what would you guess the temperature outside was when you did the compression test?

Also, was the engine warmed up?
Modified by InsanityInc at 5:15 AM 12/23/2005

[S13 240SX]

hrmmm it was really cold out but my engine as fully warmed up in a garage but it wasn't much different from standing in the garage and standing outside. both places were kinda cold but in the garage it was just warm enough for me to work in. lol. why does it matter?

[InsanityInc]

hrmmm it was really cold out but my engine as fully warmed up in a garage but it wasn't much different from standing in the garage and standing outside. both places were kinda cold but in the garage it was just warm enough for me to work in. lol. why does it matter?

Temperature will affect your compression readings. Your readings are OK, but you definitely don't have anything seriously wrong.

[S13 240SX]

does it affect it if my compression tester was sitting in my car for days while it was cold out? like does make the tool weaker or anyting if i had it out in the cold in my car for days before i used it.

[InsanityInc]

I doubt it would have gotten cold enough to cause any meaningful differences.