I think I found another way to minimize 'phantom' knock

I purchased a set of factory injectors to get them cleaned out so I could try to elminate some of the knock I was having. Lo and behold, I think I found a major contributor to my knock and poor fuel economy.

When I pulled the injectors, the seals in the head were pretty hard. I couldn't flex them practically at all! Check out these shots.

Old seal, squeezing the SNOT out of them:



New seal, using far less pressure, getting even more flex:


I figure they were causing a vacuum leak at idle and a boost leak under pressure. That could contribute to my poor ass fuel economy (I've replaced just about everything else). What do you guys think?

twkd

 

Yep, they like to do that. It should be something that everybody replaces. I keep a few extras around because those little buggers like to disappear when you remove the fuel rail.

 

[spoulson]

Great find! I think I'm going to want to swap in a set of stock injectors from a 2G I have laying around and pop some new seals on them.

 

[steve]

When I swapped injectors today I put on new isolators, and the old ones were just like that, really hard and dried up.

 

[atc250r]

Yeah mine were pretty f'ed up too. I think it should definitely be part of maintenance for these cars at their age. Besides, they're pretty damn cheap and easy to do.

John

 

Did the old ones actually leak?

In theory leaks would richen you up, and reduce "real" knock (unless you are pig rich anyways), and in that case have nothing to do with PK.

 

[marvinmadman]

Is there any way the KS could "hear" the injectors clicking because of the hard rubber not insulating like the new rubber? Just wondering, I dont have PK by the way, yet. /ubbthreads/images/graemlins/wink.gif

 

Actually, continuously running pig rich can contribute to knock, just not directly.

I figure I have a crapload of carbon buildup in the head that I can't see. Excessive carbon buildup can cause hotspots which can easily cause knock.

I should have stated this more clearly.

twkd

 

[spoulson]

But if you had a vacuum leak, you'd run lean at vacuum, rich at boost.

 

my injector seals are bad.

 

Sean, that's exactly what I was running - lean at idle (125 fuel trims) and rich under boost (fuel trims normal, though, so that's got me a little befuddled).

Any other thoughts? The car improved greatly when I replaced the injector seals, but I think I am overrunning the stock fuel pump.

I have a new fuel filter along with stock injectors that just got back from Cruizin'. I've removed the restrictor pill from the boost control solenoid, so I am running about 15psi. Do you think that I am overrunning my fuel pump? I think my duty cycle is bad, but I don't seem to have a duty cycle column in my version of MMCd tools.

twkd

 

>(unless you are pig rich anyways)

>Actually, continuously running pig rich can contribute to knock, just not directly.

Actually, you didn't need to repeat what I said.

 

MattPark, I don't understand your comment, as I didn't repeat what you said. You said running pig rich doesn't contribute to PK. I disagree. Ask Kyle Tarry about 'rich knock'.

twkd

 

dammit man this new motor in my car has all types of knock and ive tried it all including mobil 1. im with you on this one man. this sucks. i get 43 counts cruising at 65mph at 3k rpm and no boost.

hector

 

I tried EVERYTHING. The only thing that worked for me was a particular keydiver chip.

 

well i have had a keydiver chip since he started making them. 3 months ago with the motor that went south i have no knock. actually i havent seen more then 10 counts on 2 years. this motor just sucks. it doesnt do it all the time thats what pisses me off. one drive it will run perfect the next knock all over the place so the problem comes and goes. oh well one day ill figure it out.

hector

 

[steve]

I think he's referring to keydivers Phanton Knock code. Unless you asked for it, he didn't put it in your chip.

 

[Aaron]

what is the mitsu part no. for these little o-rings?

 

Quote:
what is the mitsu part no. for these little o-rings?


The top little O-ring is MD614813. The grommet that seals to the head is MD087060.

 

what im saying is that i had no knock issues before and i beat the crap out the car. this new engine just sucks with all this damn knock. its going to make me get started on my 2.3L so i can fix the knock right. what does the knock code do?

hector