How To Artical: 240sx Bad Idle And Bogging

[foulplayer]

I just recently purchased a 1992 FASTBACK SE. The car would idle would bounce up and down, dangerously, to the point where it would stall the car, and would bog in around 200rpm during hard acceleration.

Things i did:Seafoam in gas tank, in break booster, and in oil.Changed O2 sensorCheck for vaccum leak

As my luck would have it that did not fix my problem.

I took it to a respectable shop in my town, and they noticed that the LOWER head gasket (nobody in town had the lower head gasket not even the Nissan dealership). That fixed my car idle from bouncing up and down dangerously, but the idle was still rough, and the car was bogging all of the time (it felt like the car was in a too high of gear, all of the time).

I took the car back to the shop and they said that the No.4 injector was bad, they replaced it.

Now the car is running great, the car pulls hard in all RPM ranges no hesitations, and the idle is always at a 750-850 rpm.

Car Shop Costs:New Lower Head Gasket installed: $450New Injector: $136

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So Things to check first (PLEASE CORRECT ME IF IM WRONG):

-Run 'SEAFOAM' through your car: $5.60 a bottle i used 3

-Check 02 sensor: new one costed me $38

-Check for a vaccum leak

-Check the fuel injectors, injector voltage, injector pulse-width, or the nozzle tips. The O-rings tend to leak quite often giving you a lean mixture at mid-high rpm. The electical connectors also tend make a bed connection and get contaminated with corrosion once the rubber boot on the end of the plug gets ripped, torn, or worn out.

-Then if all else fails, take it to a shop and have them do a compression test. Maybe then you will find the source of the problem.------------------------------------------------------------------------------------

I hope this helps. If this Turns out to be useful PLEASE "STICKY" this post.

Like i said, if you have something to add or something to correct me, or if any of the information is useful to you, please post your 2 cents.

[JJ240]

What are you talking about lower head gasket? theres only ONE headgasket. You may have gotten ripped off because the headgasket is between the head and the block. Unless youve got a second head on your car where would you put a lower headgasket?

[U12 2NR]

he's probably talking about the gasket betwee the intake manifold and the head.

anyway..it's nice that your problem was solved, but idle problems are caused by a vast amount of things, the solution for you will most likely not be the solution for someone else.

[JJ240]

weird to refer to the intake manifold gasket as a lower head gasket though. Especially fishy for a professional mechanic to refer to it that way imo.

[Touchdown038]

Yup, I'm with JJ on this one and saying that you got ripped off. How "respectable" is this shop?