Replacing fuel pump

Re:Replacing fuel pump (TwoDogs)

Mon, 15 Jun 2020 04:45:04 GMT

This guy gives an excellent presentation on how you can determine whether your fuel pump (as well as many other areas in the fuel management) need to be adjusted/replaced.
https://www.youtube.com/watch?v=XQYDwIWS6Ho

Re:Replacing fuel pump (TwoDogs)

Mon, 15 Jun 2020 04:31:41 GMT

Hi Matt, I am in a similar situation as you. I have resisted the advice to go for an aftermarket ECU despite the superior results one would achieve. My JDM 90T was bought cheaply with the intent of teaching my 15yr old(now 21) about cars. In about 4 hours it goes back on the dyno to check fuel ratios, since replacing the 30yr old wastegate actuator with an adjustable preload Kinugawa, hopefully the AFRs have improved. Previously would only boost to 6psi, now I've had to adjust the fuel cut higher, so I know I'm getting 12psi. It is an interesting exercise, but my final goal is about 240 -250 rwhp. If I was thinking >300, I wouldn't waste time with a stock ECU. The flexibility and ease of diagnosis and adjustment of both timing and fuel trims is impressive not to mention crisp acceleration throughout. I suspect you will need that eventually so why not now.
Just my opinion.....

Re:Replacing fuel pump (Matts_SW20)

Sun, 14 Jun 2020 11:12:46 GMT

The end goal is beyond the stock fuel pump hence me wanting to replace it. The hesitation is likely from the boost solenoid as above but I'm still curious about what aspects of the fuel system can be upgraded with the standard ECU.

Re:Replacing fuel pump (TwoDogs)

Fri, 12 Jun 2020 22:15:58 GMT

Sorry just saw your comment of a significant "end goal" which may be beyond the stock fuel pump.
A hesitation sounds like something else.

Re:Replacing fuel pump (Matts_SW20)

Fri, 12 Jun 2020 20:46:46 GMT

It's fine at the moment but I don't know if its been replaced and its getting old so its prudent to think about it. There's a hesitation in acceleration at peak boost but thats potentially the boost solenoid.

Re:Replacing fuel pump (TwoDogs)

Thu, 11 Jun 2020 21:43:12 GMT

Hi Matt, why are you replacing your fuel pump ?
Is your fuel pressure weak? or AFR lean ?

Re:Replacing fuel pump (Matts_SW20)

Thu, 11 Jun 2020 20:20:43 GMT

Tried to search forum for info and results have been confusing with regards to upgrading the fuel pump or other aspects of the system when using a standard ECU. Not knowing much about upgrading a fuel system on a stock ECU I'm trying to learn as much as possible. It's been 30 years with my fuel pump so I should consider changing it soon. Given the difficulty of the task I'd like to select a pump that offers use-ability with current ECU and also not restrictive if I want to go aftermarket e.g. Link or Haltech (obviously knowing there's no pump that does stock and 500Kw, end game goals are 250Kw-275 if I get greedy).

In 2020 are the Walbro 255 and Supra TT pumps still the best option for a stock upgrade? Also what components of the system can be upgraded without changing ECU, can I use bigger rail and injectors? I would have thought that might throw ratio's all the way out with the standard ECU as it would have defined variables for fuel management.

Re:Replacing fuel pump (track_mr2)

Sat, 21 Sep 2013 11:47:05 GMT

Installing the surge tank will be very quick and easy. I would just mount it above the factory petrol filter and below the air box, that general area. You will basically use the fuel lines that are already there and having an external fuel pump is way easier to replace and check if something is wrong. I'd only replace the in tank if it let go.

Re:Replacing fuel pump (robk)

Fri, 20 Sep 2013 17:03:07 GMT

track_mr2
Why does everyone change the factory internal fuel pump? Couldn't you put a surge tank and fit a external instead using the factory in tank as the lift pump for the surge tank? Seems much easier to do.

That's definitely another option, but you would only be swapping one big task (removing the fuel tank) with the equally time-consuming task of installing and plumbing a surge tank.
In some cases a surge tank is worth having anyway, eg. a dedicated track car.

Re:Replacing fuel pump (track_mr2)

Fri, 20 Sep 2013 16:18:52 GMT

Why does everyone change the factory internal fuel pump? Couldn't you put a surge tank and fit a external instead using the factory in tank as the lift pump for the surge tank? Seems much easier to do.

Re:Replacing fuel pump (zmit)

Fri, 20 Sep 2013 14:52:37 GMT

I'm currently in the process of removing my fuel tank now, and was about to make a bit of a writeup about it. Instead, I found this from mr2oc.com. Enjoy.
http://www.lovehorsepower.com/MR2_Docs/mr2_fuel_pump_removal.htm

I got the tank ready to come out in about 2.5 hours. missing tools doesn't help though...

Re:Replacing fuel pump (Ant1)

Thu, 14 Feb 2013 17:50:53 GMT

Haha yep, that's it for sure.

Re:Replacing fuel pump (MRTurbo)

Thu, 14 Feb 2013 13:42:24 GMT

Ant1
Nope, the mechanic did though hahaha.
Yeah I did a search too, it's a stock WRX fuel pump. What the hell was that doing in there?

Iuno...your car had sex with a Rexy? " />" />

Re:Replacing fuel pump (Ant1)

Thu, 14 Feb 2013 13:22:52 GMT

Nope, the mechanic did though hahaha.

Yeah I did a search too, it's a stock WRX fuel pump. What the hell was that doing in there?

Re:Replacing fuel pump (MRTurbo)

Thu, 14 Feb 2013 09:06:03 GMT

Ant1

Got the fuel pump replaced. The one that was in it was a Unisia Jecs a42h24 fuel pump? Is that stock? I thought stock would be Denso.

So how was it... did you want to kill yourself at some point during? :D

a quick google tells me that "JECS Corporation is an automotive components company headquartered in Isesaki, Gunma, Japan and a wholly owned subsidiary of Hitachi. "

I know NISSAN had a lot to do with them, but nothing much relating to Toyota..." />