Help with analyzing my problem (video attatched)

[Burnsey]

I've got a 1989 240sx 5-spd with a DOHC (from a '91 240sx) and have replaced about everything including MAF, timing chain, water pump, intermediate sprocket, dual 12 inch fans, koyo dbl row radiator, etc, etc, etc ...

Well I am reading a 12-14 on my Vac gauge when I think its supposed to be a 20

Also problem two would be that my car makes an annoying air horn-ish sound and its loud as all get out ... and my car seems to redline at about 4,000-4,500 RPM's ... I'm going outside to make a video right now so you can see ... but does anyone know what the problem might be???

Please save me from taking it to the shop I don't trust anyone around here with that stuff.

Thanks in advance, Scott

[Burnsey]

video

http://s26.photobucket.com/alb...b.flv

[penthief]

my mustang had the same prob check the cat could be stopped up or somewhere in the exhuast

[gumby]

check for vacuum/ exhaust leaks

maybe replace O2 sensor

you sure you did everything correctly during the timing chain install?

[Burnsey]

i just got done gutting the cat ... and its got "newer" type piping from cat-back ... but it didn't make that noise while the cat was off (the air horn type noise) but was obviously LOUDER than heck b/c it was just the downpipe

[Burnsey]

check for vacuum/ exhaust leaks

maybe replace O2 sensor

you sure you did everything correctly during the timing chain install?

yeah it was all installed correctly and timing is dead on....

I do have a vac leak (its reading 12 when it should be 20)

shouldn't it throw a code if o2's are out of whack or w/e? it seemed "newer" also when i swapped it over.

[Burnsey]

anyone else else have any ideas? ... could it be like the Idle air control valve? ... I took it off and cleaned it out awhile back... but would that maybe where the vac leak is coming from and then the lack of vacuum won't let the engine rev up or something? ... I'm not so great when it comes to these things.

[CotBU]

Looks like your limiter would be at 3k not 4,000-4,500 RPM, disconnect the MAFS and run test again. It spiked to 4500 but settled at 3000 so, it's close enough to say check MAFS and the tach is always off a little. And also check the ecu for codes first, so you can tell everyone you have code 55 or whatever or not.

[Burnsey]

it is throwing the all go code (no problems).. can't remember which it was ... i think it was 55 i will get a new video tomorrow morning before class if i can get up in enough time and post up around 8 am. thanks for the response and tune back in for more

[Burnsey]

*--NEW VIDEO--*

http://s26.photobucket.com/alb...2.flv

I started the car, let it warm up ... then reved ... still got same response as earlier so I went up and unplugged MAFS and then reved again ... this time it would only rev to 2,500 RPM's ... so I dunno... also the whole time my car is like ****ting smoke. (near end of video you can see) ... anyways ... that's the updated video ... does anyone have any ideas?

Also, how many o2 sensors does the 240 have ... just the one in the downpipe o r ...?

Modified by Burnsey at 5:24 PM 8/30/2006
Modified by Burnsey at 5:51 PM 8/30/2006

[nelson8708]

sounds to me like you have a intake manifold leak. I am not sure but the hissing sound could be that. And from what i have heard your car could start to cut out early because i being too rich or too lean. If you have intake mani leak you would be running really lean. A easy way to check for a vac leak is to take brake cleaner or starting fluid and spray it around where you may suspect a leak and see if the idle changes. Hard to say with out being there. My friend had a problem with his sohc not reving very high when he hit the throttle. He ended up having some vac lines mixed up after the rebuild and install. Check to make sure your secondary butterflies are opening up when you hit the throttle. I dont have a dohc but i know the s13 dohc motors have the secondary butterflies as well. Some one get a pic of the actuator for the butterflies on the dohc so he can see what i am talking about.

p.s.all s13's only have one o2 sensor.

[Burnsey]

yeah its reading a 12 on the vac gauge when I rigged one up ... but I've tried spraying cleaner and what not on the lines but can't get the idle to change or anything to make noise ... can't seem to find the leak... and the FSM isn't the most wonderful guide to vac diagrams cause all the pics like ... the hoses just go off into an infinite abyss of white lol. but choices now are ... take mani off and do the strip down as per the Article written on it ... or take it to the shop tomorrow... I haven't decided yet, cause I seriously can't put too much more into this car ... I've already spent close to $2,000 now