randomly weak engine (Fuel system me thinks)
Thread Starter
kill it with BOOMSTICK!
Joined: Mar 2004
Posts: 1,227
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From: McHenry, IL
randomly weak engine (Fuel system me thinks)
Well, lacking the diverse knowledge of the english language to phrase this right, sporradically my car ('90 GXL, N/A of course) will spit and sputter beyond 7k rpm, as well as be a little weak on the HP (according to the good ole' butt dyno), but turn it off, wait a minute, start it again, and the problem may (stress MAY) disappear and the car will run like a champ up to 8200 rpm like she used to. My question is, from looking at all the options, it appears to be the fuel pump, but I am not sure wether or not it is the electrical or mechanical aspect that I have to worry about. I have checked voltage from ECU to pump wire at pump, and everything checks out sound. Is there any way to tell if the pump is electrically burning out (i.e. high resistance in pump) instead of foreign object damage internally?
Further more, what are my options for a decent upgrade pump that is plug and play (you know, no mechanical mods) that will work with the stock ECU and fuel system reliably and affordably (i.e. no $400 Apexi pump from rx7store). I was looking at the walbro, but I am not sure about it from some stuff I've read on the forum about them.
Thanks!
Further more, what are my options for a decent upgrade pump that is plug and play (you know, no mechanical mods) that will work with the stock ECU and fuel system reliably and affordably (i.e. no $400 Apexi pump from rx7store). I was looking at the walbro, but I am not sure about it from some stuff I've read on the forum about them.
Thanks!
dirty injectors maybe, try rewiring your fuel pump too. also a tii fuel pump would be a stock drop in and will flow a lot more. I have an extra one if interested and in good working condition. PM me if interested.
Mountain Rotary Mod
Joined: Nov 2003
Posts: 2,411
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From: Freaking Poland!!
You and I seem to have similar problems.
I've alread replaced my injectors and that helped some, but not as much as it should.
Also my SAFC shows that my car is knocking (yes the convertible cars have a knock sensor on the NA engine), so I'm guessing my car is running lean.
My next step is to replace the fuel pump with a walbro255. My plan is to make the car run rich and lean it out.
You might try and see if you can borrow a wideband O2 sensor and see what it says.
I've alread replaced my injectors and that helped some, but not as much as it should.
Also my SAFC shows that my car is knocking (yes the convertible cars have a knock sensor on the NA engine), so I'm guessing my car is running lean.
My next step is to replace the fuel pump with a walbro255. My plan is to make the car run rich and lean it out.
You might try and see if you can borrow a wideband O2 sensor and see what it says.
Thread Starter
kill it with BOOMSTICK!
Joined: Mar 2004
Posts: 1,227
Likes: 0
From: McHenry, IL
^ Well, I just got the injectors cleaned at Cruzin peroformace (forgot to mention in last post), and that didn't seem to help much, just got it running smoother, not really better. I'm thinking of going with the Walbro 255 as well, but if I can get a TII pump cheap enough, I'll take it.
