Fuel pump testing advice

freshduckie · 05-20-2006, 02:14 PM

Hey I was told I can test my fuel pump myself. How kind of gauge do I need to buy and where can it be found?

Secondly how do I do it, do I just put the gauge on the Schrader Valve?

Thanks alot

**mrr23** · 05-20-2006, 02:32 PM

yes, you put the gauge on the schrader valve and start the car and see what pressure you have. what's the reason for testing it?

freshduckie · 05-20-2006, 04:50 PM

I am get this shudder upon accleration. Can you give me any figures of pressure, what pressure am I suppose to have a idle? Do I need to check at different rpms?

What guage should I buy and where do they sell them?

Thanks

**mrr23** · 05-20-2006, 05:03 PM

auto or manual trans? you should have about 58-60 psi. most local parts stores sell a fuel pressure gauge.

freshduckie · 05-20-2006, 05:44 PM

Its a M6, is that 58-60psi at idle then? Do I need to test at different rpms as well?

freshduckie · 05-20-2006, 07:16 PM

so I got over 50psi at key on position and at idle, so I guess that means my fuel pump is fine, its probably the plugs or wires, darn it!

**ttocs** · 05-21-2006, 02:01 PM

Originally Posted by freshduckie

so I got over 50psi at key on position and at idle, so I guess that means my fuel pump is fine, its probably the plugs or wires, darn it!

You say "darn it" like its bad thing

I would much rather change my plugs and or wires then a fuel pump. I take it you dont know how to change one, it isnt fun...

Just some bogging and hesitation??? Could be as simple as you said, plugs or wires...could also be some bad gas or a clogged filter.

freshduckie · 05-22-2006, 07:26 AM

Well the filter has been changed and I really don;t want to go through all my plugs and wires cause I checked them to see if they were tight a while back, but of course I ddid not pull the plugs out. I have a warranty still and a fuel pump would be covered so I think that would be easier for me. Anyhow I am thinking maybe its the timing, any thoughts?

**ttocs** · 05-22-2006, 10:37 AM

I doubt its your timing. If its under warrenty then bring it to the shop. Dont know if will be covered or not. I can also tell you that it prolly isnt your pump. Pumps usually dont give signs of going they just die. If it does give warning its very sudden and doesnt last long. Might be your fuel pressure regulator too.

freshduckie · 05-22-2006, 10:56 AM

How do I test my fuel regulator? Why don't you think its timing? Fuel pressure was good when I tested it with with a fuel pressure gauge at key on position and idle

Thanks

**ttocs** · 05-22-2006, 03:36 PM

Originally Posted by freshduckie

How do I test my fuel regulator? Why don't you think its timing? Fuel pressure was good when I tested it with with a fuel pressure gauge at key on position and idle

Thanks

lol my bad, i totally forgot you already checked your pressure...Scratch that then. But what would make you think its your pump if your pressure is fine? It could be the timing but have you done anything to your car? miles?...i wouldent think just a degree or 2 of timing being off would make it seem as big of a prob as your describing. Unless of course youve modded your car and changed stuff around, then that increases the possibility. Some other things to throw out there...air fuel ratio-once again i doubt it...and is your motor heavily modded (bored and such?) i doubt it is but if it is then your stock pump prolly cant keep up with the fuel demands of the motor.

freshduckie · 05-23-2006, 04:19 AM

The mods are SLP Loudmouth 2 cat back (had problem before installed this), k & n filter, slp lid, skip shift gone, ws6 short shifter.

I might just have to replace all the plugs/wires one by one and see if that it.

Another problem is my rpms drop below 750 at idle and then bounce up to about 900 and settle back down to 750 so maybe I should look into TPS or is it the IAC that affects that, but I was thinking this was unrelated.

**Danger731** · 05-23-2006, 04:33 AM

Have you disconected the battery lately ?

**Danger731** · 05-23-2006, 04:34 AM

Originally Posted by freshduckie

The mods are SLP Loudmouth 2 cat back (had problem before installed this), k & n filter, slp lid, skip shift gone, ws6 short shifter.

I might just have to replace all the plugs/wires one by one and see if that it.

Another problem is my rpms drop below 750 at idle and then bounce up to about 900 and settle back down to 750 so maybe I should look into TPS or is it the IAC that affects that, but I was thinking this was unrelated.

the computer can do that.

freshduckie · 05-23-2006, 05:56 AM

What do you mean the computer can do that excatly? I have not touched the battery since teh 1st of May when I took it out of storage.

**dcperdue** · 05-23-2006, 07:31 AM

Originally Posted by freshduckie

Hey I was told I can test my fuel pump myself. How kind of gauge do I need to buy and where can it be found?

Secondly how do I do it, do I just put the gauge on the Schrader Valve?

Thanks alot

I was just the opposite first I changed my plugs wires cap and rotor and still had the jerking problem tested the fule pump and it was pulling 25 psi which is shit. So droped the exaust drained the gas tank removed gas tank and replaced fule pump. Make sure you change your plugs wires cap and rotor to do it right chances are if your plugs are that worn your cap and rotar are as well.

**dcperdue** · 05-23-2006, 07:38 AM

Originally Posted by ttocs

I doubt its your timing. If its under warrenty then bring it to the shop. Dont know if will be covered or not. I can also tell you that it prolly isnt your pump. Pumps usually dont give signs of going they just die. If it does give warning its very sudden and doesnt last long. Might be your fuel pressure regulator too.

True but surely you will notice a great loss in performance and a sure way to tell a pump is going bad is at a cold start car runs fine but after the pump gets hot you will have acceleration issues ect ect. I spent about 2k having my plugs wires cap and rotor replaced only to find out it was the fule pump. But the before mentioned can cause the same symtoms.

freshduckie · 05-23-2006, 08:18 AM

Correct me if I am wrong but does the LS1 have a cap and rotor. I am not super familar with this engine, I do know the wires go from the plugs right up to the coil packs.

Note: I have almost 52,000 miles on car, I change the plugs/wires about 7k ago.

**dcperdue** · 05-23-2006, 08:34 AM

Originally Posted by freshduckie

Correct me if I am wrong but does the LS1 have a cap and rotor. I am not super familar with this engine, I do know the wires go from the plugs right up to the coil packs.

Note: I have almost 52,000 miles on car, I change the plugs/wires about 7k ago.

No it dont I just threw that in there as an in case you have one. If you changed them 7k miles ago then thata definately not your problem and you have allready ruled out the fule pump. Take it to your dealer and have them diag it. The computer will store any NON ECM codes as well people sometimes are confused in that the computer only reports ecm problems which is not true.

freshduckie · 05-23-2006, 10:39 AM

Yes maybe I will do that, when I first did my plugs I did not have them tighten enough and I drove that way for a few days until I noticed it, could that have caused a problem?