Fuel Question

[C33_RB20DET]

My RB20DET has been giving me some problems lately. I'm thinking is a fuel problem because i changed the MAF and checked almost everything else.

I think maybe its the fuel pump..but i'm not sure so here is the problem in detail, I hope someone can help me out here..

I turned down the boost because i was getting sputtering after i press about 5% of the gas pedal. It worked ok for a while then i started missing while driving mostly in second gear.

Sometimes the engine dies and i have to pull over and wait a few seconds and start the engine up again. It starts with no problem.

Another thing is that the engine takes a while to build up in 1st gear and then on 2nd gear it dies down and takes a while to build back up,and also i notice in 2nd gear if i press the gas pedal over 5% i feel the engine holding back but if i release the pedal and slightly press it, it works ok.

Can anyone help me sort out this problem. Can you tell me if its the pump failing at a certain speed or something?I'm thinking it's happening after first because the faster you go the more fuel you need so thats why i'm thinking its the pump. ? ? ? ? ? ?

[Sil240]

Go to autozone and borrow their Fuel Pressure gauge kit.Better yet order from Summit a adapter to put a little gauge on the line.It will cost you like $25 in total.

Check your Grounds!!!I was having a similar problemI thought it was my TPS but it was just a bad ground.

[johnny butt]

Go to autozone and borrow their Fuel Pressure gauge kit.Better yet order from Summit a adapter to put a little gauge on the line.It will cost you like $25 in total.

Check your Grounds!!!I was having a similar problemI thought it was my TPS but it was just a bad ground.

Been looking for the same thing myself, having a bit of trouble locating it on their site, which one are you referring to that would work in-line with the adapter for 25$?

[kevwa]

this is what i got from summit....... http://store.summitracing.com/...w=sku http://store.summitracing.com/...w=sku i am going to switch to a fitting with AN fittings on it once i upgrade my fuel lines but for now that was cheaphttp://store.summitracing.com/...w=sku

on my truck

[johnny butt]

this is what i got from summit....... http://store.summitracing.com/...w=sku http://store.summitracing.com/...w=sku i am going to switch to a fitting with AN fittings on it once i upgrade my fuel lines but for now that was cheaphttp://store.summitracing.com/...w=sku

Cool, just the one I was looking at. The AN Fittings --- Why? I've got regular (ones it came with) fuel lines I believe, would I be alright with the fittings you've got here: (http://store.summitracing.com/partdetai ... toview=sku) ?

[kevwa]

yeah you would be fine, all i ment with the AN lines is that i want to upgrade to them eventually

[USMCgetsome]

QUOTE ME ON THIS!!! You have two independent failures. You are first experiencing a maf issue. This will cause you to die when braking towards a stop then the motor will just die. This will happen after a the engine is warmed up and driven for a few mins. Will idle great and rev great but die when coming off throttle.

The fuel pump issue should be like this...

WOT pulling revs you will feel a good flat spot in the rpms for about a sec or 2. Then it will come on hard like it's supposed to. This is a slowly failing fuel pump.

This issues your talking about is exactly what i went through with my swap down to the last detail!

Good luck.

Replaced maf. Car ran well for months. Replaced fuel pump after narrowing down all other sensors and wiring. It was then that my swap ran like it was supposed to and the power was released.

The fuel pump will show the proper pressure untill it completely fails. Hard to trouble shoot. The maf.. well we all know that's our weak link. Change it out and also think about going BLOW THROUGH SETUP.

[MATTs14]

How exactly do you do the blow through setup?

[BoostFab]

How exactly do you do the blow through setup?

i believe he's running the megasquirt, map based setup, so a maf isn't needed.

[C33_RB20DET]

well the engine is not starting at all today. so i'm 96% sure that problem would be the fuel pump..i have a spare one sitting around so i'll swap that in tomorrow morning and i also have a walbro still in the box GSS-341 so i need to get that in sometime this week but i have to clean the fuel tank first.

would have done all this today but it's sunday here and in addition to that i went out lastnight so i've got a bit of a hangover too...

Thank you so much again for your help and yes i will get rid of that MAF as soon as i can...Thank you again.

[Sil240]

If you pull down that fuel tank.Make sure you run out to the store and pick up all new lines and clamps.

The lines and clamps are probably 20 years old and dry rotted.