Silvia Club of NSW

Recently I have this problem with my 180sx

When i try to rev to about 4k - 5k rpm. It seems like a lost of power (the feeling is like the engine has not enough fuel running through). The sound of the exhaust is like puffing like sound...

Does anyone of you encounter such a problem before?

I have check the air filter (infact i have just change it).
I have check the fuel filter (change to new one).
I have check the pipings (it's not leaking).
I have check the fuel pump wiring and relay (it's ok).

The only thing I have not check and replace is the fuel pump itself.
Could it be the fuel pump is not good enough? Currently i am using a stock 180sx fuel pump.

Please help...

Thanks & Rdgs

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puffing?

If you said popping i would suggest a misfire, so check sparkplugs and coils. It's in the right area of the rev range to be a miss too.

It could also be a lean miss which would point towards the fuel pump, but i'd swap spark plugs with some bkr6es or bcpr6es copper ones at a cost of about 16 bucks and see if it improves as a start.

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meh

i tried replacing the spark plugs. It's still the same...

btw, it is not mis-firing...
The popping sound of mis-firing normally is pretty loud...

This "puffing" sound is soft but u can feel that the car is lack of the "push" - like as if it have not enough fuel...

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get a fuel pressure gauge and check what its doing at around that rpm range. if you haven't got one, most mechanics should be able to do it for you.

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Cruise & Event Photos

it sounds like you have a leak somewhere
when X amount of air is pushed through (at 4-5k) the leak opens up

i had same issue before on old car and found it was just some piping had come loose only under high pressure (boost)

I have check on the fuel regulator gauge in my car. It's seems ok.
I didn't try throttling till that rpm (4k - 5k rpm) stationary. But I did try throttling abit say to about 3k rpm, the fuel pressure gauge reads from 3 bars to about ~ 4 bars.

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thanks guys for the help...

actually it is pretty difficult to diagnose the problem as it could be anything along the line of Fuel, Air or even electronics.

But I am trying down to narrow the problems...

cheers!

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Hi Badhairdave,

You say that there might be a lean miss which would point towards the fuel pump? But previously i do not have this problem... Only recently these problem arise. In this case, could it be fuel pump?

Secondly, I would like to check. Will the fuel pump flow rate be affect by the voltage? Meaning that if the voltage supply to the fuel pump is say less than 12V, will it slow down the flow rate? Hence, not enough fuel pump to the engine?

If this is the case, how do you suggest I increase the voltage level? Will changing a higher flow rate /LPH fuel pump helps in this case?

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Can I check which area did you check that your leak comes from?

Intercooler piping?
Air Filter piping?
Exhaust piping?

Initially I thought i was leak as well... but after i check... i didn't find any leaks. Maybe I miss it out somewhere...

FYI, I find the exhaust sounds abit weird. Not the normal sound that i used to hear. Could it be exhaust leaks? I think exhaust leaking will not lead to this lose of power "symptoms", right?

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could be a turbo/exhaust manifold gasket leak...

that really sounds like a overboosting problem how much boost you run and if it is a stable amount then check all hoses incase of a tear, this happened to me last week

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SiDeWaYz
A Black Panther

I just changed my turbo (the day before) and the gasket should be new. Before i change the turbo, the problem already there.

I'll be trying to do a few things tonight to see if the problem still there:
1) replace another ECU
2) replace the coil pack
3) replace the Air flow sensor

Will let you guys know the outcome...

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yeah...!
I would think so it is an overboosting problem as well... But I cannot confirm what's wrong with it. So i have to slowly debug the problem stage by stage...

I am running at about 5k rpm and the boost reads about 0.8 - 0.9 bars. somewhere around this range.

"...overboosting problem how much boost you run and if it is a stable amount then check all hoses incase of a tear, this happened to me last week..." This sound logical to me. Because I was do 0.9 bar of boosting quite a fair bit before while playing. So i won't be surprise if there is a tear somewhere. The exhaust sound abit funny (not the usual).

Where did you find the tear?

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the tear was on my vacume hose off the BOV, but all vacume hose to do with the BOV or the boost controller can be a victim

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No one does it better than an S15
SiDeWaYz
A Black Panther

rather than spending all that time and money to diagnose a problem that could be any number of things, why not just take it to a workshop with a dyno and pay them $60 for a diagnostics run...

easier, cheaper, quicker and safer for your car. plus there's no guesswork on a dyno