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Rb20Det Fuel System Help Needed.

mattymatty4

By mattymatty4,
in Engines & Forced Induction

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mattymatty4 Explorer

mattymatty4

Posted
Posted

Alright so i need help with my fuel return. I bought and rb20det and when i went to start it up for the first time it ran like shit. I had the injectors professionally cleaned as two were had it so it was running on 4 cyl, but it only seemed to make it run worse. all vac lines are hooked up, plenty of fuel going into the injectors but nothing is coming out of the return line. any ideas? i put new spark plugs in recently and they are already black from fuel.

help much appreciated thanks

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D.I.Y. Mik Veteran

D.I.Y. Mik

Posted
Posted

Black plugs is way too rich, so the injectors are too big without some sort of control to make it run right.

sounds like they are using all the fuel, so none is returned.

What mods were done to that motor? Compression test? Leaking injectors? Blocked or kinked fuel line? Clean filters? Afm plugged in?

How did you test fuel pressure?

Rubber hose can kink under suction, like the fuel pump intake.

Once i left a rag in my intake pipe, doh! That made it run like sht.

mattymatty4 Explorer

mattymatty4

Posted
  • Author
Posted (edited)

Are you sure that you have the fuel supply and return connected to the correct side of the rail and reg and so on? Have you put a pressure gauge on it to see if the reg is actually doing anything?

this is the order i have it in 2lygrc.png

Edited by mattymatty4
mattymatty4 Explorer

mattymatty4

Posted
  • Author
Posted

Black plugs is way too rich, so the injectors are too big without some sort of control to make it run right.

sounds like they are using all the fuel, so none is returned.

What mods were done to that motor? Compression test? Leaking injectors? Blocked or kinked fuel line? Clean filters? Afm plugged in?

How did you test fuel pressure?

Rubber hose can kink under suction, like the fuel pump intake.

Once i left a rag in my intake pipe, doh! That made it run like sht.

the injectors are only stock, no mods to the engine what so ever besides a front mount intercooler. pressure was tested by an auto electrician with a fuel pressure gauge, it showed good pressure but shit fuel flow. i will replace the fuel filter on monday when i can buy one but surely it couldnt just be that could it? i will check the lines for kinked pipes thanks

89CAL Grand Master

89CAL

Posted
Posted

I'm going to replace the fuel pump and filter, if that doesn't fix it f**k it im going rb25

Your having a minor fuel issue and your going to change the whole engine?

Have you tried revving it and seeing if fuel comes out on engine decel?

mattymatty4 Explorer

mattymatty4

Posted
  • Author
Posted

Changed the filter, slightly better but still not revving properly down low.

Thanks for the tip cal, fuel is coming out on decel.

Since my plugs are black should i get new ones again?

I think i will replace fuel pump and plugs.

89CAL Grand Master

89CAL

Posted
Posted

Simple things first. New plugs, gap to .8, try again. If its better then it may have been your plugs or your coilpacks might be a bit sad

Get copper plugs, dont bother with iridium etc. Bcpr6 or bkr6 should be fine. One is slightly longer than the other. Forget which is the more commonly used

Otherwise I can give you the part number for the plugs I get from nissan. They are still ngk plugs but were reccomended by my tuner.

mattymatty4 Explorer

mattymatty4

Posted
  • Author
Posted

Simple things first. New plugs, gap to .8, try again. If its better then it may have been your plugs or your coilpacks might be a bit sad

Get copper plugs, dont bother with iridium etc. Bcpr6 or bkr6 should be fine. One is slightly longer than the other. Forget which is the more commonly used

Otherwise I can give you the part number for the plugs I get from nissan. They are still ngk plugs but were reccomended by my tuner.

thanks :) my auto electrician friend has 5 new coilpacks (couldn't find the other one) so im going to get some of those plugs you suggested and change the coilpacks, besides one..

89CAL Grand Master

89CAL

Posted
Posted

With it idling, unplug them one at a time, the one that makes the most difference to engine note/idle will be the strongest. Leave it in. Might not help much at idle but probably how id do it if I didnt want to waste too much time

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