# Won't Accelerate at all intermittently



## mmaumio (Aug 24, 2018)

Hello folks,

I won a Nissan Sunny 2003 B15 (JDM). Though it's a pretty old car but the Engine condition seems to be really good.
Not being driven a lot.

I'm having an issue where the car won't accelerate after starting the engine, which by the way starts very smoothly.
I have press the accelerator for a while and restart the car quite a few times before it starts to accelerate again.

And importantly while the acceleration is OFF the check engine light remains ON. 
As soon as it gets fixed the engine light disappears. 

I have taken it to quite a few workshops, but they couldn't figure out anything vital. 
I really doubt their efficiency on handling such issues, moreover, Nissan is not a very popular car where I Live (Dhaka, Bangladesh).
They tried changing few parts, like the butterfly valve, MAF sensor and finally the entire ECU (which I replaced back though) without any luck.

There are few patterns of that issue I can tell you.
1. If the engine gets drenched somehow or moisturized due to heavy rain (in the night) it happens in the morning.
2. it's CNG converted. When I run it on CNG it happens a lot. Then, I stopped using CNG. Still happening for last few weeks.

I've been struggling with the issue for almost 1 year.
If anyone had such issue or heard someone having could shed some light, that'd be a great help.

Thank You, everyone.

Please accept my apology if that's not the right place to post this.


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## rogoman (Dec 16, 2004)

The Nissan Sunny is a midsize car built by Nissan from 1966 to 2006. In the early 1980s, the brand changed from Datsun to Nissan in line with other models by the company. Although production of the Sunny in Japan ended in 2006, the name remains in use in the Chinese market for a rebadged version of the Nissan Latio. In North America, the later models were known as the Nissan Sentra; so for trouble shooting, you can download a copy of the FSM for the Sentra from this web site: http://www.aubreyandcharles.com/ServiceManuals/. The section EC.PDF is the one you need to read.

One of the first things to do is perform an ECU code readout with a portable scan tool to see if any fault codes are set. The tool can be purchased at most auto parts stores. Post the actual codes here on the forum so that we may be able to help you further. If there is one or more fault codes set, they can help point to the malfunction. If you have a copy of the FSM, the code readout procedure is described there along with a listing of codes.

Here are some possible causes of slow acceleration:
* - Bad engine grounding points.
* - Vacuum leaks in the intake system.
* - Low fuel pressure. 
* - Retarded ignition timing.


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## Chriscom32 (Aug 25, 2018)

One possible reason is the acceleration pedal ,if it is not cable type, they give trouble from time to time. If it's a cable type, the cable might be worn or stretched. But do get the vehicle scanned.


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