Will a bad EGR valve cause a misfire?
#1
Will a bad EGR valve cause a misfire?
I recently bought a 1991 Toyota Winnebago,its a RV on a 91 Toyota chassis.Check engine light was on when I bought it,was hoping it would be simple but having problem locating the problem.Engine{V-6 3.0} has a misfire.Its throwing code 71,egr malfunction.I cannot find a vacuum leak anywhere.replaced plugs,wires and distributor check good.Cylinders all have compression between 140-150.I did a vacuum test on EGR valve as instructed in youtube video and it held pressure.Changed fuel filter and it was full of rust so I suspected clogged fuel injector.I also checked timing,it looked good to me but it was the first time I've ever checked timing on a car before so I could be wrong on that.I finally gave up and took it to shop.
This is their diagnosis:
" Tech found only trouble code 71 egr temp sensor fault.Tech found cylinder 1 misfiring at this time.Tech found bad egr temp sensor and restricted egr valve.Concerning cylinder 1 misfire,tech found spark plug,plug cable,and distributor providing spark within specification.Tech found fuel inj resistance within spec and good signal to inj from pcm.Tech found good compression and no compression leaks on cylinder 1.Tech recommends replacement of egr valve and temp sensor."
I dont know much about engines,can do the simple stuff like what I said I have checked.I'm skeptical this is going to fix the problem and it's not a cheap fix.Apparently the egr valve for this engine is not the standard one,it's special and it's been discontinued by Toyota.I called a toyota dealership which then checked all other toyota dealers in the USA and nobody has one.Found some online parts dealers that say they have one but when called they dont.Cannot even find an aftermarket one.The Shop I took it to says they can get one but with parts and labor they want between 11-12 hundred bucks with most of that for the parts.I'm skeptical about spending that much on something they cannot guarantee is going to fix the problem.They say" it might have skipped timing but that should have shown up with compression test."
So I have paid them for their diagnosis and have the truck at home now.Thoughts?
Thanks
This is their diagnosis:
" Tech found only trouble code 71 egr temp sensor fault.Tech found cylinder 1 misfiring at this time.Tech found bad egr temp sensor and restricted egr valve.Concerning cylinder 1 misfire,tech found spark plug,plug cable,and distributor providing spark within specification.Tech found fuel inj resistance within spec and good signal to inj from pcm.Tech found good compression and no compression leaks on cylinder 1.Tech recommends replacement of egr valve and temp sensor."
I dont know much about engines,can do the simple stuff like what I said I have checked.I'm skeptical this is going to fix the problem and it's not a cheap fix.Apparently the egr valve for this engine is not the standard one,it's special and it's been discontinued by Toyota.I called a toyota dealership which then checked all other toyota dealers in the USA and nobody has one.Found some online parts dealers that say they have one but when called they dont.Cannot even find an aftermarket one.The Shop I took it to says they can get one but with parts and labor they want between 11-12 hundred bucks with most of that for the parts.I'm skeptical about spending that much on something they cannot guarantee is going to fix the problem.They say" it might have skipped timing but that should have shown up with compression test."
So I have paid them for their diagnosis and have the truck at home now.Thoughts?
Thanks
#2
Registered User
iTrader: (-1)
I recently bought a 1991 Toyota Winnebago,its a RV on a 91 Toyota chassis.Check engine light was on when I bought it,was hoping it would be simple but having problem locating the problem.Engine{V-6 3.0} has a misfire.Its throwing code 71,egr malfunction.I cannot find a vacuum leak anywhere.replaced plugs,wires and distributor check good.Cylinders all have compression between 140-150.I did a vacuum test on EGR valve as instructed in youtube video and it held pressure.Changed fuel filter and it was full of rust so I suspected clogged fuel injector.I also checked timing,it looked good to me but it was the first time I've ever checked timing on a car before so I could be wrong on that.I finally gave up and took it to shop.
This is their diagnosis:
" Tech found only trouble code 71 egr temp sensor fault.Tech found cylinder 1 misfiring at this time.Tech found bad egr temp sensor and restricted egr valve.Concerning cylinder 1 misfire,tech found spark plug,plug cable,and distributor providing spark within specification.Tech found fuel inj resistance within spec and good signal to inj from pcm.Tech found good compression and no compression leaks on cylinder 1.Tech recommends replacement of egr valve and temp sensor."
I dont know much about engines,can do the simple stuff like what I said I have checked.I'm skeptical this is going to fix the problem and it's not a cheap fix.Apparently the egr valve for this engine is not the standard one,it's special and it's been discontinued by Toyota.I called a toyota dealership which then checked all other toyota dealers in the USA and nobody has one.Found some online parts dealers that say they have one but when called they dont.Cannot even find an aftermarket one.The Shop I took it to says they can get one but with parts and labor they want between 11-12 hundred bucks with most of that for the parts.I'm skeptical about spending that much on something they cannot guarantee is going to fix the problem.They say" it might have skipped timing but that should have shown up with compression test."
So I have paid them for their diagnosis and have the truck at home now.Thoughts?
Thanks
This is their diagnosis:
" Tech found only trouble code 71 egr temp sensor fault.Tech found cylinder 1 misfiring at this time.Tech found bad egr temp sensor and restricted egr valve.Concerning cylinder 1 misfire,tech found spark plug,plug cable,and distributor providing spark within specification.Tech found fuel inj resistance within spec and good signal to inj from pcm.Tech found good compression and no compression leaks on cylinder 1.Tech recommends replacement of egr valve and temp sensor."
I dont know much about engines,can do the simple stuff like what I said I have checked.I'm skeptical this is going to fix the problem and it's not a cheap fix.Apparently the egr valve for this engine is not the standard one,it's special and it's been discontinued by Toyota.I called a toyota dealership which then checked all other toyota dealers in the USA and nobody has one.Found some online parts dealers that say they have one but when called they dont.Cannot even find an aftermarket one.The Shop I took it to says they can get one but with parts and labor they want between 11-12 hundred bucks with most of that for the parts.I'm skeptical about spending that much on something they cannot guarantee is going to fix the problem.They say" it might have skipped timing but that should have shown up with compression test."
So I have paid them for their diagnosis and have the truck at home now.Thoughts?
Thanks
can you photo the old plugs, well lit and in focus please
post a link for the video you followed
10psi varience is nearing the 10% threshold
When did the timing you followed what directions, a video of this would confirm
Difference in resistances from one spark wire to the next can cause issues. They should have probably been replaced,very cheap fix
I don't know where that EGR temp sender is, if it's like the 22re it's a diy job
How is the EGR custom, give part numbers
Jumping timing shouldn't alter compression to a major degree.
#3
describe the misfire, an audio recording would be helpful somewhat
can you photo the old plugs, well lit and in focus please
post a link for the video you followed
10psi varience is nearing the 10% threshold
When did the timing you followed what directions, a video of this would confirm
Difference in resistances from one spark wire to the next can cause issues. They should have probably been replaced,very cheap fix
I don't know where that EGR temp sender is, if it's like the 22re it's a diy job
How is the EGR custom, give part numbers
Jumping timing shouldn't alter compression to a major degree.
can you photo the old plugs, well lit and in focus please
post a link for the video you followed
10psi varience is nearing the 10% threshold
When did the timing you followed what directions, a video of this would confirm
Difference in resistances from one spark wire to the next can cause issues. They should have probably been replaced,very cheap fix
I don't know where that EGR temp sender is, if it's like the 22re it's a diy job
How is the EGR custom, give part numbers
Jumping timing shouldn't alter compression to a major degree.
https://www.youtube.com/watch?v=pOdFqKxPviA&index=1&list=FLmedPptiZTBeSLSc aVdkdHQ&t=29s
This is video for testing egr,but I did not do everything he does in the video,only hooked up the vacuum pump to see if it held pressure.Shop says they actually took egr valve off and tested it.
https://www.youtube.com/watch?v=DfFJX28Veag&t=400s
Here is a link to the valve I need
http://www.yoyopart.com/oem/11379726/airtex-4f1677.html
Yes the temp sensor is easy,the egr is probably not that hard either but since the shop had it and diagnosed it I was going to let them do it till I got the price.Now that its home if I find a valve I will probably try and tackle it my self.I know for sure the temp sensor is no good because I see it has a broken wire on it now that I'm 99% sure wasnt like that when I took it to shop.I do have a new temp sensor for it.
When shop told me how much they wanted for parts I tried to buy them myself,I bought this one and took it to shop,they say it wont work,it's not the same.
http://shop.advanceautoparts.com/p/g...rce=ir&irgwc=1
I called toyota dealer with my vin and they confirmed that part is discontinued.
Last edited by redskinman; 01-21-2017 at 04:40 AM.
#4
video of running,I'm not sure if you will be able to hear it that well.It was idling higher then normal then it does when its warmed up.https://www.youtube.com/watch?v=8yYzXCfR_2g
#5
Well found a parts house that said they can special order the egr valve,but they havent actually called the supplier so we shall see if it actually comes in.Had to pay for it up front along with shipping was 300 bucks.
#7
Registered User
iTrader: (-1)
The EGR valve used on his engine is special order, for Winny. It appears to be water cooled via the lower section of the housing.
Best case just clean it, they didn't say it was broken just "restricted". Worst case use the easy to find one and by pass the coolant hoses together.
edit: well for the next guy, since you've sourced one (maybe) already..
Best case just clean it, they didn't say it was broken just "restricted". Worst case use the easy to find one and by pass the coolant hoses together.
edit: well for the next guy, since you've sourced one (maybe) already..
Last edited by Co_94_PU; 01-22-2017 at 09:03 AM.
Trending Topics
#8
Registered User
I just cleaned my upper plenum with Easy Off oven cleaner, it was caked with crap, with some nipples completely blocked off and now it's super clean and breathing freely, maybe that EGR valve could be cleaned with the same thing i don't know if it will hurt anything on the valve.
#9
If I cannot get another one I will try to clean this one,watching some videos on youtube on how to clean EGR looks like there are some parts of the valve you do not want to get cleaner on.
#11
Well parts house couldnt get it.Since truck is over 25 yrs old I do not need to pass emissions test anymore.I've heard you can just eliminate the EGR altogether,if I do I wonder how to do that and if that will eliminate my misfire?
#12
Registered User
iTrader: (-1)
It's a long shot but isn't Winnebago still in business, maybe they have some "new old stock" somewhere you can buy?
#13
If it were mine. I would verify the two lines at the bottom that I think are coolant lines are in fact coolant lines, find the origin points and connect them with a hose bypassing the EGR valve taking care to route or shield them from exhaust heat and contact, then use the much more common EGR valve..
It's a long shot but isn't Winnebago still in business, maybe they have some "new old stock" somewhere you can buy?
It's a long shot but isn't Winnebago still in business, maybe they have some "new old stock" somewhere you can buy?
and then using a hose connector to hook those 2 hoses together and eliminating egr altogether?
#15
#16
Well I ordered the kit but wasnt sure about a couple things so I gave up.Kit says to remove the air injection pair valve.There was nothing in their diagram called that,is that the same thing as the pair reed valve? And I dont know what the air injection reed valve tube is.And I'm not sure what hoses I'm supposed to cap? Kit came with 3 small caps and 1 large,directions only mention using one of the small caps,but you remove 2 hoses off the egr and it looks like another one off the pair reed valve,then pic shows your supposed to put a cap on a hose running from the canister on the right side of engine.So I need someone with more mechanical knowledge to help me with it.
http://www.lcengineering.com/LCInstr...EGR_delete.pdf
http://www.lcengineering.com/LCInstr...EGR_delete.pdf
#18
I don't know about this version valve, but standard valve will get clogged with carbon. Take it off and clean out thin tube(s) with pipe cleaner or the like. On standard valve, there is a rubber diaphragm, this can be ruined with compressed air, just and FYI. I had a "misfire" and cleaning EGR valve helped alot (3VZE).
#19
Registered User
iTrader: (-1)
I don't know about this version valve, but standard valve will get clogged with carbon. Take it off and clean out thin tube(s) with pipe cleaner or the like. On standard valve, there is a rubber diaphragm, this can be ruined with compressed air, just and FYI. I had a "misfire" and cleaning EGR valve helped alot (3VZE).
Hello and good morning.
He has an lce block of kit. He needs precise photos of where the plates go, what tubes to remove and cap off.
#20
Well the same day I bought the block kit I took a longshot and emailed an ebay seller who I found sold one of these EGR Valves new in 2015 and asked if he had another one.He got back to me a couple days later and said his Chicago store showed they had one and he listed it and I bought it but I was still very skeptical it was the right one. Well I got it in the mail and it was the right one! So I put it on today along with new temp sensor and it didnt fix the problem although it is possible the EGR was bad.I put about 50 miles on it today and check engine light has not come back on,at least not yet.The other 2 or 3 times I've unhooked battery check engine light came back on within 10-20 miles.
So I had asked the shop I took it to before if I did change the valve and temp sensor and that didnt fix it what was the next step and he didnt have a good answer but said maybe it skipped timing.Truck wont stay running now when idling,it runs very uneven.Heres video of how it sounds now.
www.youtube.com/watch?v=lkuynYCXvjE
So I had asked the shop I took it to before if I did change the valve and temp sensor and that didnt fix it what was the next step and he didnt have a good answer but said maybe it skipped timing.Truck wont stay running now when idling,it runs very uneven.Heres video of how it sounds now.
www.youtube.com/watch?v=lkuynYCXvjE
Last edited by redskinman; 02-01-2017 at 11:59 AM.