KA24E with inconsistent fuel pressure, my issue and fix.

by ryandriftingfat on July 6, 2010

This new 240 is reminding me daily that it is almost 22 years old.  Not much productive work on the 240 lately, chasing down coolant leaks takes too much time.

Stupid cooling issues aside, I had an issue that started becoming apparent as I got more comfortable with this shell – when turning, the car was losing power, struggling to stay running. Dialing up the speed around a turn up just a bit, and the car had major problems – to the point of completely stalling. Kicking the clutch with it rolling did nothing. I could usually get it started after waiting a bit though.

My car had clearly had some work done to the fuel pump at some point; and back-alley style work at that. The top cover wasn’t bolted down and the harness plug connector cover was missing, replaced with two pieces of e-tape in an ‘X’ – classy.  Still, this felt like spark problems.

Drove the car some more, it died rounding a corner right by my office and wouldn’t start again. So it rolled the rest of the way under one human power.  Parked the car backwards in a spot and went to work, hoping it would start at the end of the day.

It didn’t. Tow truck home it is. The spot was slanted up so we had to roll the car down to get it on the truck. That’s important as I would realize later.  After the tow, I fixed some other stuff, drove the car down the street and flipped a 180 – same thing, car died and wouldn’t start, pushed it home again.

The correlation between turning hard and loss of fuel is clear here now, but this still felt like a spark problem. Pep Boys was already closed for the night so I decided to pull the fuel pump just to rule it out. This is what I found.

Hitting Google Images for “s13 fuel pump” yields a few images, one of which is this showing what a normal fuel pump assembly looks like.

The entire pickup sock for the fuel pump was missing. So the starvation condition was being caused due to fuel shift during cornering.  Also, parking on a slope, prevented the fuel from entering the pump simply due to the incline – a fluke. The part is called a “fuel pump screen” at Pep Boys, and it’s kinda pricey – mine was $22.

Quoting an excellent post from Ziptied regarding this subject, “…its not just a filter, but uses capillary action to maintain fuel around the pickup of the pump. The screen design works in a manner that, if even just one corner of the screen is touching gas, it will allow the pump to be able to suck it in.”

Makes sense to me.  The car doesn’t die going around corners anymore.  It dies for other reasons now; because it hates me.

UPDATE: 12/27/10; Make sure you buy a new fuel tank gasket after you pop open the cover. Mine was stretched over an inch beyond normal. I tried to re-use the old one because no one in town had one in stock, and I thought I got it. The smell of gas reminded me daily that I was very, very wrong.

Seriously, buy one: http://www.enjukuracing.com/nissan-fuel-pump-cover-gasket-198994-240sx-p-7633.html