Odd Miss Fires??
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From: Lake of the Ozarks, MO
Odd Miss Fires?? Im still trying to work out the bugs with my car after the cam swap. Been I fawkin nightmare. Car has a miss fire under load. It will idel just fine but if I drive it it has no power. I did injectors when I did a cam swap. Iv checked fuel pressue..its good. I thought I had a coil pack going bad, but I hear they dont go bad that often. Thought Id change the plugs to see if I had any bad ones. Well they are all BLACK as hell after two weeks of run time?? # 4 plug was wet with gas when I pulled it out, thought that would fix it, Nope pull the new plug this morning after driving it, its wet again..idk Im lost..Could it be in the tune? I know nothing about fuel injection or LS stuff..I guess I need to have someone hook it up to a scaner..
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From: Lake of the Ozarks, MO
Something else when I had the cam done, The guy told me my FAST intake had a crack in the bottom of it, not bad, very small, Its been like that for ever, I dont think that would have anything to do with it, so why now is it running like ****?
Well, a crack in teh intake, would cause a LEAN condition anyways.
Check things like a clogged or obstructed air filter, MAF screen (run a code scan and see what you come up with) and things like that.
What about fuel pressure? You got gauge? A malfunctioning regulator can cause excessive FP, could also have an injector hanging open, etc..
Let me ask you this, are ALL the plugs black and wet with fuel? Or just 1 or 2?
If ALL, you can rule out bad injectors or coil pack or wires, etc.. as the odds of every single coilpack or wire or injector going out at once, NOT gonna happen.
If just a couple of plugs are fouled, then you can look at those listed above (injectors, coil pack, wires, etc..) and NOT the MAF or clogged air filter, etc..
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From: Lake of the Ozarks, MO
Ill start by listing stuff done to the car,
LS6 Swap
.650 lift Cam/Valve Springs/Injectors
Fast90/90
Longtubes
Did the cam swap about a month ago..the car turned into a unrelable pos..before with just the LS6 it was a fast/relable bad *** car..
I had only one plug that came out wet with fuel. The rest were just black. It has New MSD wires, ACDelco Plugs, but the car runs rich to me..idk, I tested the TPS I had good voltage all the way to WOT, Fuel Pressure is 60lbs at idel and jumps from 55-65 or so at WOT. After reading about misfires, I thought maybe Crank sensor, or something like that. Under load it just has NO power and shakes..like a misfire to me. Power loss is in the higher RPMs. And after I drove it a few hunder yards and back home, the car idles kind a high like 1200-1300 RPMs..Could it be a vacum leak? Iv unhooked the battery thinking that it had a stupid spot in the tune, nope..didnt help.
Also Iv read some stuff and Im so worried that a valve spring broke or something like that. But wouldnt that make the car pop a lot.
Tomarrow its going to get hooked to a scaner..
LS6 Swap
.650 lift Cam/Valve Springs/Injectors
Fast90/90
Longtubes
Did the cam swap about a month ago..the car turned into a unrelable pos..before with just the LS6 it was a fast/relable bad *** car..
I had only one plug that came out wet with fuel. The rest were just black. It has New MSD wires, ACDelco Plugs, but the car runs rich to me..idk, I tested the TPS I had good voltage all the way to WOT, Fuel Pressure is 60lbs at idel and jumps from 55-65 or so at WOT. After reading about misfires, I thought maybe Crank sensor, or something like that. Under load it just has NO power and shakes..like a misfire to me. Power loss is in the higher RPMs. And after I drove it a few hunder yards and back home, the car idles kind a high like 1200-1300 RPMs..Could it be a vacum leak? Iv unhooked the battery thinking that it had a stupid spot in the tune, nope..didnt help.
Also Iv read some stuff and Im so worried that a valve spring broke or something like that. But wouldnt that make the car pop a lot.
Tomarrow its going to get hooked to a scaner..
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From: Lake of the Ozarks, MO
Thats my next step, but after thinking I thought I would pull the plug that was wet. Turns out its not wet, its just clean. The next plug back and in front are both black or geting dirty because they are fireing. I hooked the plug wire onto the plug, out of the engine, found a ground and turned the key, Its sparking, So..Im thinking its not geting any fuel to that cylinder..I was wrong in saying the new plugs, one was wet, it was just clean, Bad injector who knows POS!
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Kind of confused here, you say plugs are black, but clean?
Also, what size injectors? Reason I ask is, that is a lot of fuel pressure (60 PSI @ idle) you are running with that setup, especially if you have bigger injectors.
Also, what size injectors? Reason I ask is, that is a lot of fuel pressure (60 PSI @ idle) you are running with that setup, especially if you have bigger injectors.
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From: Lake of the Ozarks, MO
Broken Rocker Arm and Valve Spring turns out(Yella Terra 1.7s and a Patriot Dual Spring, The out side one broke)..42lb injectors is what I have. Im pretty sure somewere in the install someone did something wrong..Now Im hoping the head isnt junk spring wore a spot in the head..and the seat is GONE!
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As of tonight I have two valve springs broke both on the out side spring of the intake side. The issue was when the new springs came they reused the factory one piece seat, and the inner spring cant clear that so its compressing the spring to much, Wow Iv learned a lot about engines this after noon, 3 hrs ago I didnt know what a seat, seal **** even a valve spring looked like ha ha..
The speed shop is geting me all new springs, at least they are workin with me. A few people told me it will run better up top now and probably sound different..idk..
The speed shop is geting me all new springs, at least they are workin with me. A few people told me it will run better up top now and probably sound different..idk..
Well, BEFORE you put it back together, make sure you check PTV. You have broke springs and rocker arm, there is a very good chance that you have clearance issue's.
With .650 lift (have your heads been milled also?) you may have run into piston smacking your valves (PTV).
Do you know if it was checked when your combo was put together?
Also, you might have run into coil bind (spring compressed too much with that much lift)
Reason I say all this is, valve springs and rocker arms just do not break on this type of setup, unless something is way off, AND you say that your installer cracked your intake, I am starting to wonder what else was installed incorrectly???
With .650 lift (have your heads been milled also?) you may have run into piston smacking your valves (PTV).
Do you know if it was checked when your combo was put together?
Also, you might have run into coil bind (spring compressed too much with that much lift)
Reason I say all this is, valve springs and rocker arms just do not break on this type of setup, unless something is way off, AND you say that your installer cracked your intake, I am starting to wonder what else was installed incorrectly???
As of tonight I have two valve springs broke both on the out side spring of the intake side. The issue was when the new springs came they reused the factory one piece seat, and the inner spring cant clear that so its compressing the spring to much, Wow Iv learned a lot about engines this after noon, 3 hrs ago I didnt know what a seat, seal **** even a valve spring looked like ha ha..
The speed shop is geting me all new springs, at least they are workin with me. A few people told me it will run better up top now and probably sound different..idk..
The speed shop is geting me all new springs, at least they are workin with me. A few people told me it will run better up top now and probably sound different..idk..
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From: Lake of the Ozarks, MO
Cam is the MS4, Texes speed AND Patriot Peformance told me to check the seats and see if they used the factory ones from the stock 243s. BOTH said that right off the bat. They both said that I shouldnt have an issue with PTV with my set up,(they checked it at the shop also..dont know by how much or anything..) I myself dont know how to check PTV, My dad should, were the ones fixing it.. Iv checked all the rockers they are good, Pushrods havent checked yet..The speed shop is taking care of me, they are over nighting my a set of springs and already gave me new yella terras. The Intake was cracked from the previous owner not puting the right bolts in the bottom of the FAST or I guess in the vally I guess idk..its not bad its been epoxyed..
Well, just be careful and check everything once you get it back together. Several years ago when I was new to the LSx engines, I made that same mistake of using stock seal/seats. Here is a pic of what mine did. It ripped the rocker stand completely out of the heads and left a nice hole right into the intake runner. SO make sure you double check everything after this problem. Look for cracks, etc....
Well, at least 1 is broken...
Cam is the MS4, Texes speed AND Patriot Peformance told me to check the seats and see if they used the factory ones from the stock 243s. BOTH said that right off the bat. They both said that I shouldnt have an issue with PTV with my set up,(they checked it at the shop also..dont know by how much or anything..) I myself dont know how to check PTV, My dad should, were the ones fixing it.. Iv checked all the rockers they are good, Pushrods havent checked yet..The speed shop is taking care of me, they are over nighting my a set of springs and already gave me new yella terras. The Intake was cracked from the previous owner not puting the right bolts in the bottom of the FAST or I guess in the vally I guess idk..its not bad its been epoxyed..
Since the car was running, you can also look at teh tops of teh pistons, and look REAL close for any signs of contact (PTV), and look at your valves as well.
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No Im doing this all with the heads on, I just pull each cyinder to TDC, air it up to hold the valves, then pull the springs off, I know SEVERAL people that are running my set up and have talked to many techs from Texas Speed, Patriot, and others and shouldnt have PTV issues but I do understand that there is a car that is odd and could be fawkin **** up..
The reason its breaking **** is because they are coil binding i guess it what its called, becaues of the factory seats..
Pushrods checked find,
The reason its breaking **** is because they are coil binding i guess it what its called, becaues of the factory seats..
Pushrods checked find,
