Will a bad EGR valve cause a misfire?
02-08-2017, 09:57 AM
#41
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Fuel inj have been one of my main suspects this whole time{especially after seeing how dirty fuel filter vwas when I removed it} but its above my paygrade to test them or replace them,i've ran 2 bottle of seafoam thru tank and just did the berrymans 3 step fuel inj process and that did not help.
Last edited by redskinman; 02-08-2017 at 10:00 AM.
02-08-2017, 10:07 AM
#42
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Number 4 injector is under the throttle body, so at least not too hard to get to it and do some basic tests while it is in-place. Couple of thoughts on how to test include:
Ensure the connector is firmly seated on the injector. They get pretty brittle and if somebody else removed them, chances are they broke the locking tab.
Check injector resistance. Should be in the 12 to 14 range.
Check if injector actuates by connecting a temporary wire and energizing with a 9-volt battery. Just momentarily energize by touching the wire to the battery. The injector should make an audible click.
Maybe others have some ideas. Do not sell yourself short. Testing and replacing the injectors sounds intimidating, but really is not that hard. Just ask if you need more specific instructions on any of the above.
Ensure the connector is firmly seated on the injector. They get pretty brittle and if somebody else removed them, chances are they broke the locking tab.
Check injector resistance. Should be in the 12 to 14 range.
Check if injector actuates by connecting a temporary wire and energizing with a 9-volt battery. Just momentarily energize by touching the wire to the battery. The injector should make an audible click.
Maybe others have some ideas. Do not sell yourself short. Testing and replacing the injectors sounds intimidating, but really is not that hard. Just ask if you need more specific instructions on any of the above.
Last edited by DallasTX; 02-08-2017 at 10:26 AM.
02-08-2017, 01:54 PM
#43
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Number 4 injector is under the throttle body, so at least not too hard to get to it and do some basic tests while it is in-place. Couple of thoughts on how to test include:
Ensure the connector is firmly seated on the injector. They get pretty brittle and if somebody else removed them, chances are they broke the locking tab.
Check injector resistance. Should be in the 12 to 14 range.
Check if injector actuates by connecting a temporary wire and energizing with a 9-volt battery. Just momentarily energize by touching the wire to the battery. The injector should make an audible click.
Maybe others have some ideas. Do not sell yourself short. Testing and replacing the injectors sounds intimidating, but really is not that hard. Just ask if you need more specific instructions on any of the above.
Ensure the connector is firmly seated on the injector. They get pretty brittle and if somebody else removed them, chances are they broke the locking tab.
Check injector resistance. Should be in the 12 to 14 range.
Check if injector actuates by connecting a temporary wire and energizing with a 9-volt battery. Just momentarily energize by touching the wire to the battery. The injector should make an audible click.
Maybe others have some ideas. Do not sell yourself short. Testing and replacing the injectors sounds intimidating, but really is not that hard. Just ask if you need more specific instructions on any of the above.
02-09-2017, 06:43 AM
#44
Wow those are clear as mud aren't they..
The rear most vacuum line you asked about is the EVAP system (charcoal can) and it stays connected.
See the two hoses in the diagram on top of the throttle body marked in grey as "to remove" that's the location for the two 1/8" vacuum caps.
I'm not sure what they were trying to indicate with that other circle on, the engines right side , near where the egr valve was but if for some reason it's sucking air in one of those still the locals bigbox partstore sells vacuum caps.. send the bill and hate mail to lce over that if so.
The rear most vacuum line you asked about is the EVAP system (charcoal can) and it stays connected.
See the two hoses in the diagram on top of the throttle body marked in grey as "to remove" that's the location for the two 1/8" vacuum caps.
I'm not sure what they were trying to indicate with that other circle on, the engines right side , near where the egr valve was but if for some reason it's sucking air in one of those still the locals bigbox partstore sells vacuum caps.. send the bill and hate mail to lce over that if so.
02-09-2017, 07:44 AM
#45
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Wow those are clear as mud aren't they..
The rear most vacuum line you asked about is the EVAP system (charcoal can) and it stays connected.
See the two hoses in the diagram on top of the throttle body marked in grey as "to remove" that's the location for the two 1/8" vacuum caps.
I'm not sure what they were trying to indicate with that other circle on, the engines right side , near where the egr valve was but if for some reason it's sucking air in one of those still the locals bigbox partstore sells vacuum caps.. send the bill and hate mail to lce over that if so.
The rear most vacuum line you asked about is the EVAP system (charcoal can) and it stays connected.
See the two hoses in the diagram on top of the throttle body marked in grey as "to remove" that's the location for the two 1/8" vacuum caps.
I'm not sure what they were trying to indicate with that other circle on, the engines right side , near where the egr valve was but if for some reason it's sucking air in one of those still the locals bigbox partstore sells vacuum caps.. send the bill and hate mail to lce over that if so.
The rear most vacuum line in the video is really the only one i'm pretty sure where the cap goes.It doesnt go to the canister,it's a short hose{about 6" long} that was hooked to pair valve.looks like you remove that hose and put cap over pipe {in the pic where it says 5/8" cap}it's just hard to get to up against the firewall and under plenum.
The kit came with 3 small caps but instructions arent real clear.Looks like youre supposed to cap one coming off bottom of vacuum modulator and not where I capped it in the video.As for the where the other 2 caps go{and where I point to in the video}looks like I might have had that backwards.If you sayI remove 2 at that spot then I would think it would be the other 2 hoses that I did not point at in the video,is that correct?
thanks
02-09-2017, 08:20 AM
#46
Ok thanks
The rear most vacuum line in the video is really the only one i'm pretty sure where the cap goes.It doesnt go to the canister,it's a short hose{about 6" long} that was hooked to pair valve.looks like you remove that hose and put cap over pipe {in the pic where it says 5/8" cap}it's just hard to get to up against the firewall and under plenum.
The kit came with 3 small caps but instructions arent real clear.Looks like youre supposed to cap one coming off bottom of vacuum modulator and not where I capped it in the video.As for the where the other 2 caps go{and where I point to in the video}looks like I might have had that backwards.If you sayI remove 2 at that spot then I would think it would be the other 2 hoses that I did not point at in the video,is that correct?
thanks
The rear most vacuum line in the video is really the only one i'm pretty sure where the cap goes.It doesnt go to the canister,it's a short hose{about 6" long} that was hooked to pair valve.looks like you remove that hose and put cap over pipe {in the pic where it says 5/8" cap}it's just hard to get to up against the firewall and under plenum.
The kit came with 3 small caps but instructions arent real clear.Looks like youre supposed to cap one coming off bottom of vacuum modulator and not where I capped it in the video.As for the where the other 2 caps go{and where I point to in the video}looks like I might have had that backwards.If you sayI remove 2 at that spot then I would think it would be the other 2 hoses that I did not point at in the video,is that correct?
thanks
The confusion is "your left" vs "engines left", lce stuff just says "left" which is ambiguous. Your left when looking in to the engine bay is the engines right side.
OK so you have the large pair port using the 5/8, two throttle body ports using 1/8, and the last one goes onto a hardline coming from the VSV array to the egr valve. (That last one is due to a cross connection in the VSV array, and should make since looking at them now you have a better sense of what and why?)
02-09-2017, 12:10 PM
#47
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(PostScript as pre-script, now I've reread your post to make sure I covered everything... Yes! Two forward lines at the throttle body get removed and capped.)
The confusion is "your left" vs "engines left", lce stuff just says "left" which is ambiguous. Your left when looking in to the engine bay is the engines right side.
OK so you have the large pair port using the 5/8, two throttle body ports using 1/8, and the last one goes onto a hardline coming from the VSV array to the egr valve. (That last one is due to a cross connection in the VSV array, and should make since looking at them now you have a better sense of what and why?)
The confusion is "your left" vs "engines left", lce stuff just says "left" which is ambiguous. Your left when looking in to the engine bay is the engines right side.
OK so you have the large pair port using the 5/8, two throttle body ports using 1/8, and the last one goes onto a hardline coming from the VSV array to the egr valve. (That last one is due to a cross connection in the VSV array, and should make since looking at them now you have a better sense of what and why?)
If I am understanding you correctly,then right now I have 1 cap in the right place{hard line coming from VSV array,that originally had 3 inch hose coming from it to top of EGR valve}I still need to remove 6" hose and put on 5/8" cap,final step,instead of capping the 1 line I point finger to in video,I need to cap the other 2.
Thank you for the help
02-11-2017, 06:25 AM
#48
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Havent gotten to work on anything yet,working today also.
I have been googling this but cannot find a definitive answer.Since cylinder #4 seems to be where misfire is coming from but compression is good,does that eliminate the need for a leak down test? Or is leak down test only neccessary when compression is bad? Is it possible I might have a bad valve even if compression is good?
thanks
I have been googling this but cannot find a definitive answer.Since cylinder #4 seems to be where misfire is coming from but compression is good,does that eliminate the need for a leak down test? Or is leak down test only neccessary when compression is bad? Is it possible I might have a bad valve even if compression is good?
thanks
02-11-2017, 04:37 PM
#49
Havent gotten to work on anything yet,working today also.
I have been googling this but cannot find a definitive answer.Since cylinder #4 seems to be where misfire is coming from but compression is good,does that eliminate the need for a leak down test? Or is leak down test only neccessary when compression is bad? Is it possible I might have a bad valve even if compression is good?
thanks
I have been googling this but cannot find a definitive answer.Since cylinder #4 seems to be where misfire is coming from but compression is good,does that eliminate the need for a leak down test? Or is leak down test only neccessary when compression is bad? Is it possible I might have a bad valve even if compression is good?
thanks
QA
No, you can still have issues with rings and valves. Take for example a valve seal which wets down the piston rings (and fouls a plug), this cylinder will have a higher compression but during a leak test eventually that oil is going to work passed the rings and show a discrepancy. It will start off with less leakage than a dry cylinder then fade.
The compression test is very good at finding gaping holes in the gasket, burned valves, and broken rings. It can tell you that there is cylinder imbalance but not why, leak testing gives a why or at least where.
02-11-2017, 06:39 PM
#50
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im still wondering why it moved from number one to four..
QA
No, you can still have issues with rings and valves. Take for example a valve seal which wets down the piston rings (and fouls a plug), this cylinder will have a higher compression but during a leak test eventually that oil is going to work passed the rings and show a discrepancy. It will start off with less leakage than a dry cylinder then fade.
The compression test is very good at finding gaping holes in the gasket, burned valves, and broken rings. It can tell you that there is cylinder imbalance but not why, leak testing gives a why or at least where.
QA
No, you can still have issues with rings and valves. Take for example a valve seal which wets down the piston rings (and fouls a plug), this cylinder will have a higher compression but during a leak test eventually that oil is going to work passed the rings and show a discrepancy. It will start off with less leakage than a dry cylinder then fade.
The compression test is very good at finding gaping holes in the gasket, burned valves, and broken rings. It can tell you that there is cylinder imbalance but not why, leak testing gives a why or at least where.
As far as the leak down test goes,I guess a more specific question would be do you think a leak down test is necessary in my circumstance when all cylinders are testing between 140-150?
02-11-2017, 09:12 PM
#51
Worth doing probably, paying for some one to do it probably not at this point. I will remind you that the variance limit is about ten percent and you're getting close to that and need to investigate why. It's likely to just be valve wear but could be "bad things".
When my last head gasket let loose a cold compression test still showed less than 1-2 psi variation, small enough to not be measured on the Napa gauge I have. I had 120 psi at #1 and around 125 on the rest, with a dead battery, the gasket failed between #2 #3
Link, the post following that one shows the blowouts on #2. A leak down test would have showed air leaking into the coolant passages..
When my last head gasket let loose a cold compression test still showed less than 1-2 psi variation, small enough to not be measured on the Napa gauge I have. I had 120 psi at #1 and around 125 on the rest, with a dead battery, the gasket failed between #2 #3
Link, the post following that one shows the blowouts on #2. A leak down test would have showed air leaking into the coolant passages..
02-12-2017, 09:08 AM
#52
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Worth doing probably, paying for some one to do it probably not at this point. I will remind you that the variance limit is about ten percent and you're getting close to that and need to investigate why. It's likely to just be valve wear but could be "bad things".
When my last head gasket let loose a cold compression test still showed less than 1-2 psi variation, small enough to not be measured on the Napa gauge I have. I had 120 psi at #1 and around 125 on the rest, with a dead battery, the gasket failed between #2 #3
Link, the post following that one shows the blowouts on #2. A leak down test would have showed air leaking into the coolant passages..
When my last head gasket let loose a cold compression test still showed less than 1-2 psi variation, small enough to not be measured on the Napa gauge I have. I had 120 psi at #1 and around 125 on the rest, with a dead battery, the gasket failed between #2 #3
Link, the post following that one shows the blowouts on #2. A leak down test would have showed air leaking into the coolant passages..
02-12-2017, 10:32 AM
#53
Git yer rednek OHN
Could be clogged injector still. Not real accurate a measurement but it will tell you if it's fully plugged up.
Rotate the crankshaft to open #4 intake valve, insert a test strip to catch fuel, manually fire the injector bank with the fuel pump jumpers on.
PS, what did and does that plug look like?
Rotate the crankshaft to open #4 intake valve, insert a test strip to catch fuel, manually fire the injector bank with the fuel pump jumpers on.
PS, what did and does that plug look like?
02-12-2017, 01:54 PM
#54
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Could be clogged injector still. Not real accurate a measurement but it will tell you if it's fully plugged up.
Rotate the crankshaft to open #4 intake valve, insert a test strip to catch fuel, manually fire the injector bank with the fuel pump jumpers on.
PS, what did and does that plug look like?
Rotate the crankshaft to open #4 intake valve, insert a test strip to catch fuel, manually fire the injector bank with the fuel pump jumpers on.
PS, what did and does that plug look like?
02-12-2017, 02:24 PM
#55
You have ash deposited, that shows it is/was firing at least some at one point.
It's dark and chunky not dark and sooty, that means oil not over fueling.
bottom third of the ground strap is still shiny, that means it's not been ran up to higher speed or maybe its not combusting more than half of what it's given at WOT.
Pretty typical of a leak at the valve stem..
It looks like the electrode might be bent, anybody else seeing that(?), that's not a denso feature that I am aware of..
Wondering if you can get any garbage out of that cylinder.. I would pull the computer fuse, the #4 plug, hook up jumper cables to another running engine, hold a clean white catch rag to #4 and crank the bejebus out of it... Or put a bore scope down it if that's more hillbilly than you have in you..
It's dark and chunky not dark and sooty, that means oil not over fueling.
bottom third of the ground strap is still shiny, that means it's not been ran up to higher speed or maybe its not combusting more than half of what it's given at WOT.
Pretty typical of a leak at the valve stem..
It looks like the electrode might be bent, anybody else seeing that(?), that's not a denso feature that I am aware of..
Wondering if you can get any garbage out of that cylinder.. I would pull the computer fuse, the #4 plug, hook up jumper cables to another running engine, hold a clean white catch rag to #4 and crank the bejebus out of it... Or put a bore scope down it if that's more hillbilly than you have in you..
02-12-2017, 04:20 PM
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You have ash deposited, that shows it is/was firing at least some at one point.
It's dark and chunky not dark and sooty, that means oil not over fueling.
bottom third of the ground strap is still shiny, that means it's not been ran up to higher speed or maybe its not combusting more than half of what it's given at WOT.
Pretty typical of a leak at the valve stem..
It looks like the electrode might be bent, anybody else seeing that(?), that's not a denso feature that I am aware of..
Wondering if you can get any garbage out of that cylinder.. I would pull the computer fuse, the #4 plug, hook up jumper cables to another running engine, hold a clean white catch rag to #4 and crank the bejebus out of it... Or put a bore scope down it if that's more hillbilly than you have in you..
It's dark and chunky not dark and sooty, that means oil not over fueling.
bottom third of the ground strap is still shiny, that means it's not been ran up to higher speed or maybe its not combusting more than half of what it's given at WOT.
Pretty typical of a leak at the valve stem..
It looks like the electrode might be bent, anybody else seeing that(?), that's not a denso feature that I am aware of..
Wondering if you can get any garbage out of that cylinder.. I would pull the computer fuse, the #4 plug, hook up jumper cables to another running engine, hold a clean white catch rag to #4 and crank the bejebus out of it... Or put a bore scope down it if that's more hillbilly than you have in you..
02-13-2017, 06:23 AM
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Ok I bought the leak down tester.If it fails the test I'm not going to know the why or where,I'm just going to know it didnt hold air.If it does fail,does this mean head gasket is failing or it could be a number of other things?
Is it possible it just needs valves adjusted? I doubt they have ever been adjusted{currently 124,000 miles}
And if it passes the leakdown test,what else could it possibly be? I know it can still be a clogged inj,but besides that?
thanks
Is it possible it just needs valves adjusted? I doubt they have ever been adjusted{currently 124,000 miles}
And if it passes the leakdown test,what else could it possibly be? I know it can still be a clogged inj,but besides that?
thanks
02-13-2017, 07:31 AM
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You might want to read up on a leak down test.
First, how would you know it "failed"? The first level of usefulness of a leak down test is comparison to your engine at another time (using the same tool). There is no absolute pass/fail number, and the number you get with any engine will be different between testers. (While it's technically possible to calibrate the orifice in YOUR tester, I've never heard of anyone doing it.)
Even though you don't have a baseline reading, you certainly can use it to compare between cylinders. And for what it's worth, on my fine-running 3VZE, I get about 35% with my tester.
"If it fails the test I'm not going to know the why or where" No, actually, that is one of the GOOD things about a leakdown test. If you have a cylinder that seems to be leaking, you can HEAR it in the exhaust, or the intake, or in the dipstick tube, or sometimes by seeing bubbles in the radiator. You'll have leakage in those areas even with good cylinders, but with bad ones the noise will be pretty easy to pick up.
First, how would you know it "failed"? The first level of usefulness of a leak down test is comparison to your engine at another time (using the same tool). There is no absolute pass/fail number, and the number you get with any engine will be different between testers. (While it's technically possible to calibrate the orifice in YOUR tester, I've never heard of anyone doing it.)
Even though you don't have a baseline reading, you certainly can use it to compare between cylinders. And for what it's worth, on my fine-running 3VZE, I get about 35% with my tester.
"If it fails the test I'm not going to know the why or where" No, actually, that is one of the GOOD things about a leakdown test. If you have a cylinder that seems to be leaking, you can HEAR it in the exhaust, or the intake, or in the dipstick tube, or sometimes by seeing bubbles in the radiator. You'll have leakage in those areas even with good cylinders, but with bad ones the noise will be pretty easy to pick up.
