Stumble after start during warmup, slight miss at idle and rev up 2v 00’
#1
09-16-2018, 07:51 AM
Stumble after start during warmup, slight miss at idle and rev up 2v 00’
Hello all and good morning.
I have a 00’ v10 2v in an EX.
need some help with a couple problems. Not sure if they are related or not.
Been pretty much same
1st.
Start truck cold cold fires within a couple revolutions, high idle,smooth, all good.
A few minutes after start as idle comes down there is stumble, hesitating idle that clears up within a minute on its own or if I get back in and rev it up it clears. Only noticeable when truck sits to warm up. If you just get in start and drive this is not noticeable
I have read somewhere that the computer can cause this condition when coming off open loop cold start and picking up info for closed loop. Not sure.
#2
very slight miss at idle and stays with it while reving up in neutral. Not noticed during normal driving. Towing mileage is 7.5-9.5 depending on terrain and 12ish unloaded. So I don’t think it’s a major problem yet. This truck rarely sees the highway. Mostly county and state roads. So mpg won’t ever be in flat lander highway commuter territory.
Notes-
-new coil boots less than 1000 miles.
-checked all plugs, good color and gap
-had one cop fail completely 400 miles ago. Very obvious and easy fix. Autozone cheapie replacement.
-new fuel pressure regulator 2 years ago.
-fuel pressure was fine then idle and under load.
-2 years ago when I bought it, ran awful under load. Took a long time to find clogged cat. First and last honey comb were intact and not sooted up. Ones in between were broken and clogging exhaust. It is now hollowed out for visual emmisions inspection only in NYS. No sensor post cat.
-maf cleaned had no effect.
- truck is summertime family vacation hauler or towing only. 3000 miles a year.
- run Seafoam through twice in fuel, no effect.
- exhaust has strong odor that I attribute to no cat but my my motor savy diy dad says is too strong for that. He says it’s rich. Mpg says it’s normal I think.
Any ideas appreciated.
Thanks
I have a 00’ v10 2v in an EX.
need some help with a couple problems. Not sure if they are related or not.
Been pretty much same
1st.
Start truck cold cold fires within a couple revolutions, high idle,smooth, all good.
A few minutes after start as idle comes down there is stumble, hesitating idle that clears up within a minute on its own or if I get back in and rev it up it clears. Only noticeable when truck sits to warm up. If you just get in start and drive this is not noticeable
I have read somewhere that the computer can cause this condition when coming off open loop cold start and picking up info for closed loop. Not sure.
#2
very slight miss at idle and stays with it while reving up in neutral. Not noticed during normal driving. Towing mileage is 7.5-9.5 depending on terrain and 12ish unloaded. So I don’t think it’s a major problem yet. This truck rarely sees the highway. Mostly county and state roads. So mpg won’t ever be in flat lander highway commuter territory.
Notes-
-new coil boots less than 1000 miles.
-checked all plugs, good color and gap
-had one cop fail completely 400 miles ago. Very obvious and easy fix. Autozone cheapie replacement.
-new fuel pressure regulator 2 years ago.
-fuel pressure was fine then idle and under load.
-2 years ago when I bought it, ran awful under load. Took a long time to find clogged cat. First and last honey comb were intact and not sooted up. Ones in between were broken and clogging exhaust. It is now hollowed out for visual emmisions inspection only in NYS. No sensor post cat.
-maf cleaned had no effect.
- truck is summertime family vacation hauler or towing only. 3000 miles a year.
- run Seafoam through twice in fuel, no effect.
- exhaust has strong odor that I attribute to no cat but my my motor savy diy dad says is too strong for that. He says it’s rich. Mpg says it’s normal I think.
Any ideas appreciated.
Thanks
#2
09-16-2018, 01:25 PM
I have found that I cannot detect a single misfire on my V10. It only becomes noticable after a 2nd cylinder misfires. I check mine with the torque app every couple months because I cannot feel a single cylinder misfire.
So my recommendation is to look for another cylinder mifire.....either coil, or injector. Personally I replace injectors with fresh ones every 100,000 miles or so. It keeps spray patterns and fuel volumes good. It only cost about $120 for all 10.
for you my suggestion is check coils, plugs, and injectors. Maybe clean IAC too. I dont clean the IAC, I just put a new one on if I think it's the issue. But some people prefer to try to save the old one.
last bit to check is the coil and injector clips. They become brittle and crack. One or more could be not seated well and connection is bad causing misfire.
So my recommendation is to look for another cylinder mifire.....either coil, or injector. Personally I replace injectors with fresh ones every 100,000 miles or so. It keeps spray patterns and fuel volumes good. It only cost about $120 for all 10.
for you my suggestion is check coils, plugs, and injectors. Maybe clean IAC too. I dont clean the IAC, I just put a new one on if I think it's the issue. But some people prefer to try to save the old one.
last bit to check is the coil and injector clips. They become brittle and crack. One or more could be not seated well and connection is bad causing misfire.
#3
09-16-2018, 10:14 PM
Fleet Mechanic
#4
09-17-2018, 11:11 AM
#5
09-17-2018, 11:49 AM
Fleet Mechanic
It may the timing chain tensioners.
Our 2003 5.4L with 175k "ticks" a lot on cold start up and is fine after 4 or 5 min.
It started around 150k and the ticking takes longer and longer to stop.
It's down right now, I just finished collecting all the parts, changing oil pump, too, since it is really easy on an Exped with the removable cross member.
Is your clatter on the passenger side?
#6
09-18-2018, 07:59 AM
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As for clatter on startup, some amount is normal, too much is not great. I tried running 5W30 in a past oil change to see if the thicker oil would stick around the top end more and help with cold start clatter. It made it much worse and lasted for 5 - 10 seconds. I'm currently running 0W20 and cold start clatter lasts 1 - 2 seconds, if at all. Even with all the noise, the wear numbers with the 5W30 looked good on the oil analysis. I've still got a couple thousand to go before I test to see how the 0W20 is affecting engine wear.
#7
09-18-2018, 07:51 PM
Vacuum leak.
I’ve had vents cut out before climbing hills. Turned out 4wd actuator was stuck open. Took a bit to find that.
No noticable clatter on startup. That is a dry bearing slap sound.
This is more like lash adjusters that are not holding pressure but it goes away...light ticking. Moves around cylinder heads. Can’t say its one area or one side.
Oil pressure is in the high normal range on dash gauge. 10-30 conventional now. I got a barrel for free 8 years ago. Almost empty. Grrr. No more free oil changes. Everything got 10-30. Honda 2.4 vtec went 245k before I sold it. 10k between changes. Not sure type or viscosity is really that critical beyond actual proper ambient temp range.
Like I mentioned though noticeably quieter just after oil change. Don’t drive it much so that was last summer.
Do these timing chain tensioners rely on oil pressure to apply proper tension or spring loaded guides like jap crap?
No noticable clatter on startup. That is a dry bearing slap sound.
This is more like lash adjusters that are not holding pressure but it goes away...light ticking. Moves around cylinder heads. Can’t say its one area or one side.
Oil pressure is in the high normal range on dash gauge. 10-30 conventional now. I got a barrel for free 8 years ago. Almost empty. Grrr. No more free oil changes. Everything got 10-30. Honda 2.4 vtec went 245k before I sold it. 10k between changes. Not sure type or viscosity is really that critical beyond actual proper ambient temp range.
Like I mentioned though noticeably quieter just after oil change. Don’t drive it much so that was last summer.
Do these timing chain tensioners rely on oil pressure to apply proper tension or spring loaded guides like jap crap?
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#8
09-18-2018, 08:20 PM
Fleet Mechanic
The first tensioners used on these engines were cast iron and had ratchets to take up more and more slack without completely retracting.
The newer plastic tensioner does not have the ratchet so will retract more.
Don't know what year the change was made.
An oil pump that has a warped backing plate may leak enough to affect pressure.
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