Knock knock......

[Grand natty garage]

I been chasing knock at higher rpms for a while now. Think I finally figured it out, fuel pump is original and I noticed the pressure drops after reving out. O2 milivolts seem to be normal but I haven't watched them when it's reed out. I'm about to install my a/f gauge to see what that's reading. Blm 128 and alky kicks on amd ramps when it's supposed to. I ordered a new deatchwerks 255lph pump. Once that's installed, I'll post an update if any one is interested. I'm not gonna do any more pulls until that new pump is in, don't wanna open a can of worms..

 

[TexasT]

You are playing with fire on that original fuel pump. New pump and a hot wire at the minimum or you will be going deeper into the engine sooner then later.

 

[Grand natty garage]

You are playing with fire on that original fuel pump. New pump and a hot wire at the minimum or you will be going deeper into the engine sooner then later.

You are playing with fire on that original fuel pump. New pump and a hot wire at the minimum or you will be going deeper into the engine sooner then later.

Absolutely, I agree! Honestly it should have been the very first thing I did when I got the car years ago. I've had the hotwire for a wile but never touched the pump. New one gets delivered Monday

 

[Chuck Leeper]

fuel pump is original

What Rich said, and....
Filter too?
Injs clean?
When the tank is down, change the tank to frame hoses.
Verify voltage and ground at the tank hanger connection.
Volt drop tests are always a good idea with this type of issue.

 

[dynoman]

First , list all your mods to the car in your signature so we don't have to ask " do you have this or that " . I'll assume you have a Scanmaster ...correct ? If you don't have a Powerlogger , get one . It will help narrow down any issues . Also are you checking alky pump pressure ? Just because it's turning on doesn't mean it's pumping with any pressure and this is overlooked on many Alky injected cars .

 

[Grand natty garage]

What Rich said, and....
Filter too?
Injs clean?
When the tank is down, change the tank to frame hoses.
Verify voltage and ground at the tank hanger connection.
Volt drop tests are always a good idea with this type of issue.

New 42 injectors, put a new online filter in last month. Just got the new pump, came with sock. I'm getting 12-14v to the tank when I Rev it because of the hot wire kit. I'll be replacing the hoses when I do the pump.

 

[Grand natty garage]

First , list all your mods to the car in your signature so we don't have to ask " do you have this or that " . I'll assume you have a Scanmaster ...correct ? If you don't have a Powerlogger , get one . It will help narrow down any issues . Also are you checking alky pump pressure ? Just because it's turning on doesn't mean it's pumping with any pressure and this is overlooked on many Alky injected cars .

I'll have to do that, thanks. The mods are 42lb injectors and a TT chip combo, chip is flashed for alky and 20-22 of boost. I have it at 20 right now. Has a racetronix regulator and gauge, hot wire kit, and a GN1 performance stock size turbo, and the alky control kit. That's it. Yes I have the scan master G, I also have an A/F gauge with the wide band sensor. I know the pump has pressure and is working. It bogs and dies when I hit test wile idling. Also after a few runs, the tank level drops a good amount. However, I can't confirm exactly how much pressure. The knock is a pre existing issue to the alky Install, even at lower boost. I'll have the new pump in hopefully this weekend and will update.

 

[SCOOBY DOO]

Chasing KR with an original fuel pump. Someone stop by and take the keys from him.

 

[Grand natty garage]

Chasing KR with an original fuel pump. Someone stop by and take the keys from him.

Your a riot! I love this guy!

 

[Mr.Spool]

New 42 injectors, put a new online filter in last month. Just got the new pump, came with sock. I'm getting 12-14v to the tank when I Rev it because of the hot wire kit. I'll be replacing the hoses when I do the pump.

Dosnt mean your getting fuel to the cylinders Take the injectors and have them flowed

 

[Grand natty garage]

Dosnt mean your getting fuel to the cylinders Take the injectors and have them flowed

I'll do that, thanks!

 

[Grand natty garage]

Update, new pump is in. That solved some of the knock, still have it sporadically . Decided to change my tensioner pulley and that solved it. Crazy how something like that could cause it.

 

[Chuck Leeper]

Decided to change my tensioner pulley and that solved it. Crazy how something like that could cause it.

A well known problem.

 

[Grand natty garage]

I appreciate the advice and help