please help last attempt, sluggish 240

[smokin240]

My 93 240 just doesnt have any "snap" to it at low (under 2300) and high (over 3300) RPM after about 3 minutes of driving it, basically after it warms up (which I think is the key to the whole thing). But, when I gear down to second going about 45ish the exhaust pops and passing about 5500 RPM the engine seems to kick in and actually throws me back in the seat, like it should all the time. Any other time its really sluggish (other than when I just started it up) and it also smokes extremely bad the first time I drive it and drive it hard but I think thats due to the thick oil I put in it to help the engine tapping. In fact if I stomp it to the floor it’s actually more sluggish than If I ease into the pedal. I have to rev it a little more than normal to get it moving from a dead stop because the engines dogs out so much. I’ve tried the MAFS but it was from a used car, that didn’t help. I’ve checked the rotors and cleaned the erosion off, still no go. Also tried replacing the coil. I think I have narrowed it down to three things, clogged cat, bad injector(s), o2 sensor, or fuel pump and maybe possibly a vacuum leak. I really don’t have the money to dish out and fix all these problems so im hoping maybe someone has had this exact problem before or seen it and knows how to fix it. Not to discourage anyone but i’ve had 5 or so mechanics actually look at it and try to guess whats wrong and I lost count on how many i’ve talked to about it and they can only guess. This has been going since i’ve had this car and this is the last attempt im going to try and fix this, if no worky then im selling. It’s suppose to be a sports car not a sentra with real wheel drive. Thank you all for the help and hopefully i can finally get this fixed.

[NateDogg]

100% no questions asked...

Coolant Temperature Sensor! (the red one)

Good luck and don't forget to burp the coolant after you replace it!

[smokin240]

Ok its 29.99 at Napa not too much but if this works you will be my new best friend. Im picking it up today and wont have my car running until this weekend but i'll let you know. By the way how are you 100% sure? I've had so many mechanics look at it and could only guess. Someone today again mentioned the catalytic converter but I don't see how that would be it if it runs fine until about 2 minutes later its crap. Makes since if it was on a domestic car but with imports it could be anything.

[slide240slide]

Have you checked the timing? Exhaust popping, Sluggish acceleration, Ticking noise, those sound like problems associated with loose timing chainoor out of time how many miles does this 240 Have? The Coolant temp. sensor just signals the PCM to switch to closed loop after it see's specified engine temp. although if it is bad the PCM will think the engine is still cold and supply more fuel thinking the motor is cold when in fact it is at operating tempature. Did you pull the plugs were they black (rich)? does the exhaust smell heavy with fuel? if you checked these things and they did check out to be true i would guess it to be the Coolant temp sensor. and i have seen Cat's that the car runs good for a few minutes and then runs like **** after warmup from The Cat being expanded by the Heat of the exhaust. most the times with a Restriced exhaust you will have very high RPM's and engine sounds like it is under a severe amount of loadwithout and you can get under the vehicle and hit the case with a glove on and if it rattles it's bad the Honeycomb has separated from the case and has most likely cracked into smaller pieces clogging the outlet. Hope some of this helps! Good luck man!

[coolcloo1019]

i have the same exact problem. Replaced the coolant tempurature sensor, checked timing, new fuel pump, fuel filter. Nothing is working. Can't figure it out.

[NateDogg]

All you dudes should try cleaning your electrical sensor connections with electrical contact cleaner and/or sand paper. Then check to see if the readings are within factory spec.

Some common failures include: MAFS, TPS, Coolant Temp Sensor, O2 Sensor.

BTW SMOKIN240: I would NOT use a NAPA part. Nissan's parts and QC are hard to duplicate so you should only use a Nissan part. Shouldn't be any more expensive than $30.

[coolcloo1019]

i paid 19.99 for my coolant temp sensor....

NateDogg: ill give those things a try...i've cleaned most of my connections but ill see if there is anything im missing. When WOT it seems like the engine is racing like crazy but im not going anywhere...

[smokin240]

It has about 168k on it. The cat doesn't glow at night and the engine idles fine at around 700 after warming up. So maybe it is the sensor? Maybe the timing chain? How do you check it if it is working correctly? thanks again

Edit: Also one guy actualy took off the oil cap as the car was running and the engine didn't dog down like he said it should, which means, he said, that it was probably a vacuum leak. He suggested spraying some carb cleaner around the hoses to see if the engine actually revs up and that will show the leak. Sound right? Could it even be this?
Modified by smokin240 at 1:54 PM 2/3/2005

[NateDogg]

It has about 168k on it. The cat doesn't glow at night and the engine idles fine at around 700 after warming up. So maybe it is the sensor? Maybe the timing chain? How do you check it if it is working correctly? thanks again

Edit: Also one guy actualy took off the oil cap as the car was running and the engine didn't dog down like he said it should, which means, he said, that it was probably a vacuum leak. He suggested spraying some carb cleaner around the hoses to see if the engine actually revs up and that will show the leak. Sound right? Could it even be this?

You should have a FSM (Factory Service Manual). You can download it from northwestnissans.com in the general section I believe. It will tell you what the specs are for your sensors.

The true test for the vacuum leak is to take a pair of plyers and pinch the blow-by hose that goes to the intake pipe. If the idle does not change, you dont have a vacuum leak. Another way to check if you have a vacuum leak is to get a vacuum gauge and stick it onto the charcoal canister line (near air filter). Should read about 18-22in Hg. Anything much less will indicate a vacuum leak or worn piston rings/valvetrain.

coolcloo1019: sounds to me like your clutch is slipping. Please provide a detailed description of what is happening in your case.

[JPG0511]

I had the same problem with mine until i cleaned the inside of the maf senor. I just used carb cleaner once i got it off and sprayed it off. Now my car runs alot better. Even if it doesnt fix your problem a can of carb cleaner is under 2 bucks.

[smokin240]

Do you mean by pinching it and it does nothing it has a leak? Because if it did wouldn't it be sucking air from somewhere else and be fine, therefore showing it has a leak? By the way, how do you install a coolant temp sensor anyhow? Not too hard I hope, this clutch replacing thing is a nightmare and alot of people said it was generally easy, and I have the right tools too I had to actually drimmel the wire harness's off the transmission because they wouldnt come apart, and theres 15 million screws and getting to them is another story and trust me thats not even half of it.... uggghh don't want to get me started

[smokin240]

By the way, what did you mean by "the red one"? Theres only 1 to choose from.

[coolcloo1019]

By the way, what did you mean by "the red one"? Theres only 1 to choose from.

you will also see another sensor near the coolant temp...it might be yellow, mine was anyways.

replacing the coolant temp sensor is easy...you need a deep socket, i believe 19mm, correct me if im wrong anyone. take off the wire, unscrew the sensor, and put the new one in...simple as that

[gumby]

you could eliminate the aiv system in case its malfunctioning. wont affect performance just emissions. for the cost of a manifold plug and a couple rubber caps like $10. my engine had 2 open vacuum lines because of that stupid thing.

if it was the cat youd probly smell it.

also give seafoam a try if your gonna change the o2 sensor anyway it really works well at freeing up the valves. im gonna try an oil wash with it in the spring.

seafoam gooooooood

ah hell im just guessing. for your sake i hope it isnt injectors, or timing cause then your sunk. those are the 2 major things that go. not smelling fuel or hearing tickin are good signs.

[smokin240]

my engine is "ticking/tapping" but I thought it was for other reasons....

[coolcloo1019]

natedogg...figured out my problem...compression is 90 across the board...that could explain my slowness...

[drftnassmofo]

that ticking coming from the front of your motor is most likely the upper timing chain guide..just remove the valve cover and take it out..better do it b4 it eats a hole through the water jacket..if it already has then you are screwed....i still havent removed mine but..ill be doin it as soon as i bring my car into class..btw..this willNOT affect performance unless it eats up the water jacket..but believe me eventually it will

[hpdrumakk]

the upper timing chain guide wont EAT through a water jacket.... itll just eventually break loose and most likely end up in the bottom of your oil pan.... the ticking noise most 240 owners hear from their cars is the LOWER timing chain.... the tensioner wears out and it gets loose and starts hitting the front cover.... not really a big deal at all unless u drive w/ it like that for like 50000 MILES.... and besides if it ever did happen your oil would have a **** load of coolant in it

[smokin240]

I finally figured out the problem, 6 mechanics, numerous non mechanics, $500, and almost 2 years later. It wasn't the coolant temp sensor, I replaced that and nothing happened. My engine light wasnt on which means non of my sensors were malfunctioning... I didn't think of that until after I replaced it. Anyway, what it was was spark plug wires. I went and took it to get and induction service done to clean out the fuel system and the mechanic drove it and said you have something seriously wrong, referring to the sluggishness. He instantly recommended a tune-up then said spark plug wires. So we did the Induction and put the new plug wires and I went to drive it and about cried. Not really but I was so freakin happy I could've hugged the mechanic Even though he overcharged me out the arse for it im still happy. It runs like a dream now besides the ticking, probably the mechanic said is caused by the lifters. Out of all things, the spark plug wires? Apparently they were sparking against the wall inside the engine and there was carbon like deposites on the plug wire. Next thing is new plugs! Thanks all for helping

[nab911]

Lol good job man. Glad to hear your not throwing it away!