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rettilajoie
New User
Sep 8, 2010, 12:09 PM
Post #1 of 5
(1358 views)
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a tricky one...
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hey there all... ok i have a 94 nissan d21 95,000 miles
everything has always been great on this lil truck
but something strange has started...
lets say im in 3rd gear going about thirty... when i just barely press the accelerator to maintain speed there is a slight miss.. the miss is more noticeable at low rpm but it seems it is only when i just barley press the gas.. if i push the pedal down a lil further it goes away. this will happen in all gears. tps throttle positioning sensor? do i even have one of those on this? truck runs perfect other than this. no light has come on so no codes.. it idles perfect.
i have changed fuel fileter,had the injectors cleaned at walmart, new oil, cap,wires and button and plugs.. and boy i needed a new cap! but alass the same symptoms  any help would be great! ill answer any questions i can.. thanks guys i keep thinking vacum but it all looks good maybe some slight cracking.. not really sure how to test that stuff tho
(This post was edited by rettilajoie on Sep 8, 2010, 12:12 PM)
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Tom Greenleaf
Ultimate Carjunky
/ Moderator
Sep 9, 2010, 12:04 PM
Post #2 of 5
(1335 views)
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Re: a tricky one...
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I'd check for vacuum leaks at any area sealing intake manifold vacuum or lines with carb cleaner at idle. If idle changes at a given spot that spot or item is suspect. Careful as carb cleaner is flammable so go easy and sparingly anywhere near hot parts.
By your description of a part throttle, part load issue that's the exact time an EGR valve is to operate. It should do nothing at idle or with full throttle request so it's suspect now. Try unplugging vacuum hose to it (like is that way) and plug the hose. If problem goes away there's an issue with the EGR. Try that and we'll take it from there. It doesn't necessarily mean the EGR is bad but would suggest it's working too much or leaking somehow at that point,
T
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rettilajoie
New User
Sep 10, 2010, 1:08 PM
Post #3 of 5
(1322 views)
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Re: a tricky one...
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hey thank you i will try and locate the egr valve. i need a manual for this truck. any suggestions where to start looking? i changed one on a van but cant remeber what it looked like
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Tom Greenleaf
Ultimate Carjunky
/ Moderator
Sep 10, 2010, 3:57 PM
Post #4 of 5
(1317 views)
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Re: a tricky one...
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I can't speak for every vehicle ever made but it should be on intake manifold where exhaust gases are available to mix some spent vapor into incoming fuel and air to reduce temp of combustion which in turn reduces NOx emissions and can control knock. Assorted designs could do that differently.
It might not have one. The problem could easily be something else. You are there and I'm here and can't see it and point it out for you with any data I have,
T
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phyman92
New User
Sep 15, 2010, 11:18 PM
Post #5 of 5
(1294 views)
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Re: a tricky one...
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^very well said. it's actually harder than troubleshooting a computer on the phone.
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