Need your help!

Bustedsm

Bustedsm

Numbered Car Crazy
Alright fellow SyTyer's, I've been dealing with this phantom knock issue for several months now to no avail. The distributor is brand new, wires are brand new, plugs are getting replaced Thursday, knock sensor is brand new, intercooler pump works.

I can't seen to figure out what to do next, for a near stock truck at 16lbs I'm seeing almost 19* of knock at WOT!! :oops: I don't go around mashing the gas all the time because I'm afraid of ruining my truck, which I don't need to do.

I played around with Tunerpro and completely yanked all the timing at WOT and seeing a peak of 2* advance I still see 8 counts of knock. :rant:

What else am I missing?
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Need your help!

DanenGraham said:
False knock??

Does it do it when you are just reving the motor up, in neutral.
Click to expand...

No, I haven't gotten it to do that. I'm spending the whole day tomorrow trying to get ready for Nats, I don't want to go down there, try to run my truck just to blow it up :(
 
G

GM TURBO

Sell Out
Re: Need your help!

If you have less by adjusting the timing I'd say it's for rizzle knock.

What's your build? What's your ignition condition?
 
G

GM TURBO

Sell Out
Re: Need your help!

Sorry - I missed the first paragraph.
Depending on age and type of plugs - it could be that.

New knock sensor make a difference? More? Less?
 
Loeryder

Loeryder

New member
Re: Need your help!

When you change the plugs use an ohmeter to check the resistance of the wires.
I know they are new but the boots can be damaged pulling them off and on.
I use a boot puller on the plug ends every time to help prevent this.
Little dab of dielectric grease also keeps them from "freezing" to the plug.

Also be sure they are all seated on the dist cap.
Some dist caps have longer "necks" where the wires snap on and if you have a wire with a deeper boot they don't sit down like they should.
Saw this issue on my wife's Subaru running Magnacore wires buts its japanese. ;)

If the plugs don't help and the wires all check good I would start looking at the fuel pump also.
I will have a press gauge and timing light at Nats for you to use.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Need your help!

Loeryder said:
When you change the plugs use an ohmeter to check the resistance of the wires.
I know they are new but the boots can be damaged pulling them off and on.
I use a boot puller on the plug ends every time to help prevent this.
Little dab of dielectric grease also keeps them from "freezing" to the plug.

Also be sure they are all seated on the dist cap.
Some dist caps have longer "necks" where the wires snap on and if you have a wire with a deeper boot they don't sit down like they should.
Saw this issue on my wife's Subaru running Magnacore wires buts its japanese. ;)

If the plugs don't help and the wires all check good I would start looking at the fuel pump also.
I will have a press gauge and timing light at Nats for you to use.
Click to expand...



Thanks Jason, I've had all the plug wires off before and used an actual puller as so I wouldn't damage the boots. I'll be picking up plugs today and putting them in tomorrow a long with a ton of other things I'm doing to prep for Nats.

I have a really good light and will also be picking up a pressure gauge to check the pump.

The new knock sensor did help out a little, but not much. I still don't understand how I'm seeing soooo much knock though, my motor should of given out by now if it were 100% real.

I've also seafoamed the truck but might do it again.
 
Loeryder

Loeryder

New member
Re: Need your help!

Sounds like you are on the ball and covering all the bases.

Seafoam intake cleaner requires the plugs to be trashed and replaced after a burn off like that.
Good for evacuating the area of any mosquitoes also.

You might check your coil also, weak spark could cause knock like that.
Ign module under the distributor, usually that's an on or off type device. it works or it doesn't.

Have you pulled the cap n rotor to inspect it for wear?
Might have some arcing buildup or wear on the tip of the rotor.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Need your help!

Loeryder said:
Sounds like you are on the ball and covering all the bases.

Seafoam intake cleaner requires the plugs to be trashed and replaced after a burn off like that.
Good for evacuating the area of any mosquitoes also.

You might check your coil also, weak spark could cause knock like that.
Ign module under the distributor, usually that's an on or off type device. it works or it doesn't.

Have you pulled the cap n rotor to inspect it for wear?
Might have some arcing buildup or wear on the tip of the rotor.
Click to expand...


New cap and rotor, coil is brand new as well. I'm pretty sure the ignition module is within spec but I didn't check it.

I guess you're right with the plugs, I'm going to seafoam the truck again and then change the plugs to NGK UR6 and gap 'em a little tighter (.031) and see hwat she does.
 
G

GM TURBO

Sell Out
Re: Need your help!

I hate to preach the ignition sermon - but it seems more times than not, that's the issue.
 
K

KGB Pilot125

New member
Re: Need your help!

pull the front propshaft and see if it goes away. had the same problem on 2234 and after the front shaft blew itself apart the false knock went away...
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Need your help!

KGB Pilot125 said:
pull the front propshaft and see if it goes away. had the same problem on 2234 and after the front shaft blew itself apart the false knock went away...
Click to expand...

I want a good launch!!! Ok, I'll give that a shot tomorrow. The shaft is stock so I'm sure it's junk or getting there.
 
K

KGB Pilot125

New member
Re: Need your help!

Bustedsm said:
I want a good launch!!! Ok, I'll give that a shot tomorrow. The shaft is stock so I'm sure it's junk or getting there.
Click to expand...

we were actually reading datamaster and trying to fix the phantom knock issue when the drive shaft came apart. the rear joint broke and flung around taking out the cable and denting the floor pan but ill be damned if the knock didnt disapear.
 
S

syclone0209

Member
Re: Need your help!

did you try putting some high octane in it and see if any of it goes away. also look for downpipe hitting frame, or a loose rocker.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Need your help!

syclone0209 said:
did you try putting some high octane in it and see if any of it goes away. also look for downpipe hitting frame, or a loose rocker.
Click to expand...

I put E85 in a little while ago which is known to suppress detonation (From previous experiences with my VR4) and it didn't change. Had the valve covers off previously and all the rockers were in spec. My injectors click pretty badly but I don't see how that'd cause "false knock."

I'll be pulling the intercooler to the side tomorrow and looking at the downpipe also.
 
SloGN

SloGN

9Sec Alky V6
Re: Need your help!

check the motor mounts. if the downpipe is hitting my bet the pass side mount is crushed.
 
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