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Subject: "Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?" Previous topic | Next topic
VenzFeb-09-10 09:33 PM
Member since Jan 22nd 2006
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#129566, "Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"


          

So here is the story, I bought some used oem fuel injectors online for my mitsubishi eclipse 1997 420a. The car was running fine before switching the injectors.

My mechanic replaced them for me, and when I drove the car home, everything was fine until I floored it.

The car started to die out when coasting to a stop. I could keep it from dying out by keeping my foot on the gas.

A lot of oil spilled out from the intake manifold oil recirculation to my cold air intake.
CEL gave a miss firing code. Turns out cylinder 4 wasn't firing at all.

He did a compression test and found out that the cylinder is losing compression.
It could be a possibility that the car had bad compression before hand, as I had alot of blow-by.

He told me the valves got damaged from the me driving with the bad injectors.

I said, cant I just replace the injector every thing will be fine?

he said no, the damage is already done. Even if i replaced the faulty injector the car will still run rough and will miss-fire

So its either a valve job or replace the injectors which my mechanic claims will do nothing.

what do you guys think of this?

http://www.dsmregistry.com/detail.php?carid=1377

97 GS eclipse turbo'ed with stage 2 hahn FMIC

  
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Replies to this topic
RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, 420agreenvilleSC, Feb-09-10 11:30 PM, #1
RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, Moderatorbullettdsm, Feb-10-10 02:56 AM, #2
RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, Venz, Feb-10-10 03:57 AM, #3
      RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, ez, Feb-10-10 09:58 AM, #4
      RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, Moderatorbullettdsm, Feb-10-10 10:20 AM, #5
      RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, Venz, Feb-10-10 12:05 PM, #6
      RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, bagged420a, Feb-10-10 12:29 PM, #7
           RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, Venz, Feb-10-10 12:31 PM, #8
           RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?, 420agreenvilleSC, Feb-10-10 12:33 PM, #9

420agreenvilleSCFeb-09-10 11:30 PM
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#129567, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 0



          

so, if the car was running fine before the injectors were installed, then why did you replace the injectors. your mechanic is brainless btw

___________________________________________



http://www.2gnt.com/quote_db.php?id=278

Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac
Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim

  
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ModeratorbullettdsmFeb-10-10 02:56 AM
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#129569, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 0
 Feb-10-10 03:00 AM by bullettdsm

          

Originally posted by Venz
So here is the story, I bought some used oem fuel injectors online for my mitsubishi eclipse 1997 420a. The car was running fine before switching the injectors.


Why replace them then?


Originally posted by VenzMy mechanic replaced them for me, and when I drove the car home, everything was fine until I floored it. The car started to die out when coasting to a stop. I could keep it from dying out by keeping my foot on the gas. A lot of oil spilled out from the intake manifold oil recirculation to my cold air intake. CEL gave a miss firing code. Turns out cylinder 4 wasn't firing at all. He did a compression test and found out that the cylinder is losing compression. It could be a possibility that the car had bad compression before hand, as I had alot of blow-by. He told me the valves got damaged


Possibility. Did he do a leak down? I would wonder in that situation whether or not the piston/rings were any good. Could have been having a problem with worn rings prior and a stuck injector just exacerbated the problem (or a "testing" of the new injector install - high reving to be sure that the injector is working properly - may have been the "last straw").

Originally posted by Venz He told me the valves got damaged from the me driving with the bad injectors.

No I don't think so. Unless the injector caused excessive heat to be generated inside that cylinder (maybe lean?), I can't see it causing the valve to burn. Kinda a moot point now.


Originally posted by VenzI said, cant I just replace the injector every thing will be fine? he said no, the damage is already done. Even if i replaced the faulty injector the car will still run rough and will miss-fire


That is correct.

Captain Caveman

96 RS Turbo 11.414 @ 119.62 MSNS, Crower 2 NA cams, BW366, 10.5 comp, UDP, 60mm TB, W/A intercooler, 3.55 tranny 567.9whp 430tq
97 RS NA 13.188 @ 103.87 MSnS powered 12.5 comp, Crower 3's and 219.4whp with 175tq
98 RS DD 12.5 comp on stock ECU, LTH, Crower 2's, Koni, GC, Hypercoil, DG hats
99 OZ 5sp Stocker 15.856 @ 85.97
99 GS stocker auto 17.7@77mph!

wiki home page:http://www.2gnt.com/index.php?d=bullettdsm

  
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VenzFeb-10-10 03:57 AM
Member since Jan 22nd 2006
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#129570, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 2
 Feb-10-10 04:01 AM by Venz

          

Replaced the injectors because my car was turbo'ed and i had higher flow injectors in them.

Originally posted by bullettdsm
No I don't think so. Unless the injector caused excessive heat to be generated inside that cylinder (maybe lean?), I can't see it causing the valve to burn. Kinda a moot point now.

isnt that basically my situation? one of the injectors wasnt working. thus, making the cylinder run super lean, causing damage.

Originally posted by bullettdsm
Originally posted by VenzI said, cant I just replace the injector every thing will be fine? he said no, the damage is already done. Even if i replaced the faulty injector the car will still run rough and will miss-fire
That is correct.

so you are saying there is no point for me to install a brand new injector in there because the cylinder will still run rough and misfire?

http://www.dsmregistry.com/detail.php?carid=1377

97 GS eclipse turbo'ed with stage 2 hahn FMIC

  
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ezFeb-10-10 09:58 AM
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#129574, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 3

          

What exactly are your compression numbers?

2gnt: '99 RS-T, killed by a toyota, pending rebuild...
Daily: Volt
Daily #2: '99 EVG ebike- STOLEN by PEDRO

  
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ModeratorbullettdsmFeb-10-10 10:20 AM
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#129575, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 3

          

Originally posted by Venz
so you are saying there is no point for me to install a brand new injector in there because the cylinder will still run rough and misfire?


IF you have a burnt valve, changing an injector will not fix the valve.

Captain Caveman

96 RS Turbo 11.414 @ 119.62 MSNS, Crower 2 NA cams, BW366, 10.5 comp, UDP, 60mm TB, W/A intercooler, 3.55 tranny 567.9whp 430tq
97 RS NA 13.188 @ 103.87 MSnS powered 12.5 comp, Crower 3's and 219.4whp with 175tq
98 RS DD 12.5 comp on stock ECU, LTH, Crower 2's, Koni, GC, Hypercoil, DG hats
99 OZ 5sp Stocker 15.856 @ 85.97
99 GS stocker auto 17.7@77mph!

wiki home page:http://www.2gnt.com/index.php?d=bullettdsm

  
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VenzFeb-10-10 12:05 PM
Member since Jan 22nd 2006
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#129577, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 5
 Feb-10-10 12:22 PM by Venz

          

it is 80 psi compression

I understand it won't make the valves better, but the problem is I don't see how driving with bad injectors damaged my valves so bad that it needs a valve job.

And let's just say the cylinder has low compression, wouldn't the cylinder still work if I replaced the bad injectors so it can fire properly?

http://www.dsmregistry.com/detail.php?carid=1377

97 GS eclipse turbo'ed with stage 2 hahn FMIC

  
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bagged420aFeb-10-10 12:29 PM
Member since Mar 12th 2009
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#129578, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 3
 Feb-10-10 12:31 PM by bagged420a

          

Originally posted by Venz
Replaced the injectors because my car was turbo'ed and i had higher flow injectors in them.


How much bigger did you go? I saw in your list on that site you posted says your tunning with a SAFC.

EDIT: Nevermind this post read it wrong. Sorry

  
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VenzFeb-10-10 12:31 PM
Member since Jan 22nd 2006
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#129579, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 7

          

Originally posted by bagged420a
Originally posted by Venz Replaced the injectors because my car was turbo'ed and i had higher flow injectors in them.
How much bigger did you go? I saw in your list on that site you posted says your tunning with a SAFC.


I think 270cc

http://www.dsmregistry.com/detail.php?carid=1377

97 GS eclipse turbo'ed with stage 2 hahn FMIC

  
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420agreenvilleSCFeb-10-10 12:33 PM
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#129580, "RE: Miss-fire in cylinder 4 because of injectors. bad injectors leads to valve job?"
In response to Reply # 7



          

drop about a half cap full of oil in that cylinder, then do another compression test. If it jumps, it's your rings/ring lands. If it doesnt, it's in your head.

Regardless of what happens, im sorry, but plan for a tear down. 80 is way low.

___________________________________________



http://www.2gnt.com/quote_db.php?id=278

Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac
Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim

  
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