I own a 1992 240SX and having problems with acceleration. It only does it in first gear and at the beginning of the accerleration, around 1000 to 3000 rpm's. what do you think is the problem? I changed my spark plugs and wires. I also change my distributor cap and rotor, but still shows these problems.

MaKeysa Walters
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Check to see you don't have any vacuum leaks, specifically from the BPT Valve and EGR Valve. I have been having the same problems for the past two months and I opted to find the answer to this problem once and for all. At first, I thought it was the injectors, since I've had several instances where my check engine light turned on and the code it read was "45", which is "fuel injector leak." Upon removing the injector rail, I noticed a crack in the rubber hose that connects the BPT Valve and the EGR Valve. It is like a 5" long hose under the BPT Valve that goes directly to the EGR Valve. After replacing that hose, as well as other tubing attached to the BPT Valve to avoid future problems, my first gear acceleration improved significantly. So, check for cracked hoses that causes vacuum leak.


Question 2

I have a 90 coupe, and I'm having problems accelerating. If you accelerate really slowly, i.e. barely keeping up with traffic, the car runs fine, but when you apply even moderate throttle pressure, the car bogs, backfires, and seems to misfire. It seems the   timing chain tensioner is gone, ( makes a rattle when starting ), but a Nissan mechanic said that's not it (?). We have changed or checked: O2 sensor, driver side engine mount, BPT valve, AAC valve, FICD solenoid, hoses ( gonna recheck ), MAF sensor, Throttle position sensor, and the computer cannot detect anything as not working properly. I still have to adjust the ignition timing ( mechanic set to 10 deg instead of 15 ), and I'm gonna replace the ignition wires just to be sure, oh yeah, new distributor as well. Any help would be really appreciated. I'm pretty stumped.

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Re. 1

I would not offend anyone by suggesting a fuel filter? You shouldn't just
replace stuff and hope it fixes it. find out what's wrong. it'll save money.
the tapping may be the lifters pumping up. the chain would rattle all the time,
not just at start up. good luck

Chris Tice
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Re. 2

The problem is your fuel pump. I had the EXACT same problem in a toyota of mine. have your fuel pumped replaced and your filter cleaned.

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Re. 3

I recently fixed this problem on my 1990 240sx by simply replacing the air feeder hose. There was a big crack in it which I actually just taped up first with duct tape...the part cost me $100 CAD so I had to save up for it ;)

The hose is about 5" across and not too long. It sits right behind the radiator - if you're facing the car its behind the left corner of the rad...you can't miss it, really big and made of plastic. You might want to check other hoses for vacuum leaks etc.

With that simple change, the engine runs like new again!! It really incredible actually...doesn't bog down low anymore and feels much peppier.

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Re. 4

I  changed my fuel filter and now the car runs fine. also use ngk plugs and wires. i used motomaster once(canadian tire brand) and they really hurt my acceleration.

Name: jimmy arfanis
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Re. 5

Like the guy above, i had the same symptons on my 1983 honda prelude and it turned out that there was a kink in the fuel line right after my fuel pump. turns out that this kink screwed up my fuel pump as well... so i had to replace the pump and fix the line...

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