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rough idle and knock!

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geno414

10+ Year Contributor
440
4
Jan 13, 2011
Milwaukee, Wisconsin
Came home from work fixed a alternator belt and put some (stp red bottle) in my car .

The car starts up a bit rough and i will have to keep my foot on the gas wile it warms up . When it is warm it sounds like I have some big big cams in my car witch I don't . My a/f bounce around a bit two but most of the time it will be around 14 . My idle will bounce a little bit from 1000 to 500 when I start breaking it will die some times I don't know what is the problem it just randomly came and when building boost I will get a check engine light for knock witch I never ever get it is protune on dsmlink.

I have a 6 bolt swap done the right way support mods the works .

I replaced the plugs to see if that was it but didn't make a difference . Swapped coil pack nope nothing did some sea foam to my car to see if that stp messed it up nothing.

I tested all injectors checked for lose wire or anything looked for boost leaks found one fixed it still did not fix my car . The car runs good on the high way besides when I build boost and get a code for knock and then the hole idle thing. My timing was set right and was done right my base time on dsmlink is 5* o2 is cycling like it should nothing adds up really I am stump PLEASE if any one has had a problem like mine can you help and yes I have looked on the Internet for a answer already
 
well I changed the plugs because I had old ones in my car and thought they were just bad but it didn't make any change and yea im going to stay away from STP! and oil stuff but I did go back to day one and nothing really adds up I mean I have my oil psi gauge grounded to my alternator but even when I un hook that it still runs the same even tested the alternator and it came back good all my grounds are good and all my harness are good also .

So, sticking to the theme of the problem starting when you made those changes and assuming that you didn't knix anything during your maintenance, I'd start checking everything that the additive touched, component by component. If the engine is idling funny and bucking under load after you made a change to the fuel system with the additive, it stands to reason that something about the fuel system has gone awry.

I suspect what may have happened is that, if you added the STP to the tank, the extra detergents in that stuff may have broken up some sediments and gotten them lodged in your pump, which has a piss poor pickup-side filter. Your fuel filter should have blocked any additional gunk from making it further upstream to the injectors (which is why when you checked them they seemed ok). So, I would start at the pump with a bench test, not just a read on the rail pressure while revving the car in your driveway. If that checks out, try purging your fuel system again with fresh gas. If both of these things fail you probably have a controls issue to sort out.
 
Well I have a big update took my a wile but here is the update any help can help me out so . I checked my ecu and it was good so I cleaned it two and the wires .

Took out my rc 600 cc and put in stock still does it . Checked all wires and plugs and cleaned them also and checked for righr fuel pressure checked the fuel pump also and it still does the same exact thing I made a short log if any one would like to view it I also have the older one on this forum still thanks let me know what you think really need my car fixed was forced to buy a$ 250 beater so I could make it to work and back.
 
Can you make a video, upload it on youtube "publicly" ?
The other video uploaded was of no use.
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here is a video I really need help fixing my car any ideas I checked all most everything just today I took my valve covor off to see if I had anything broken in that but I don't
 
If your alternator was overcharging it creates a high voltage spike which might have fried the ecu try another to b safe.
 
If your alternator was overcharging it creates a high voltage spike which might have fried the ecu try another to b safe.
It wasn't over charging at all I have my stock boost gauge set up as my volt gauge and I also just checked my ecu and nothing is fried or burnt or leaking it just sucks nothing is working and I can't just order new parts to throw on it and no one by me that I know owns a car like mine they all drive Hondas ....
 
Well I would check all mechanical first compression,timing,fuel psi,then electrical the ecu can still be fried even if it don't look or smell burnt so don't knock it
 
Well I would check all mechanical first compression,timing,fuel psi,then electrical the ecu can still be fried even if it don't look or smell burnt so don't knock it
Well I tested the timing and it is dead nuts on the compression is good two and I clean all sensors and plugs to but I just bought a new isc because my idle is bouncing up and down a but and I don't know if it is good or bad it is the old gold top model and I bought the new black one . Did you watch my video or look at my log
 
I saw the video couldn't open the log and from what I'm seeing it sounds like the ecu is toast and u said u get a knock code and ur knock sensor is good that leads me to believe the ecu isn't computing properly.
 
I saw the video couldn't open the log and from what I'm seeing it sounds like the ecu is toast and u said u get a knock code and ur knock sensor is good that leads me to believe the ecu isn't computing properly.
Yes I get about 8.4 knock if I one it up a bit the knock sensor is a oem I replaced it maybe a year ago there is no leaks coming from it . Ok I will see if I can grab a new ecu from eBay or something
 
your 02 isnt cycling right. looks to me as you have a exhaust leak pre 02 sensor. mine is doing the same at the moment and it runs rough.
Yea my down pipe ripped open at the flex pipe hit some ice and it broke the hole thing is open could that be a problem is yours running like mine at all?
 
Yea my down pipe ripped open at the flex pipe hit some ice and it broke the hole thing is open could that be a problem is yours running like mine at all?

I think by the ecu config you still run stock lambda? if your 02 sensor is before the exhaust damage, it shouldnt realy affect it. Can you check for exhaust leaks pre 02 sensor ?

Car was running like yours (like big cams when on stock) before i fixed a bad boost leak. Did a turbo upgrade and fmic install etc. Didnt see it on my boost gauge (vacuum) because of increased flow i think. On stock smic kit i realy could see leaks, because of bad vacuum.

Your timing is also jumping allot. Same symptons is found when having a bad crank / cam sensor i think. Look it up.
 
I think by the ecu config you still run stock lambda? if your 02 sensor is before the exhaust damage, it shouldnt realy affect it. Can you check for exhaust leaks pre 02 sensor ?

Car was running like yours (like big cams when on stock) before i fixed a bad boost leak. Did a turbo upgrade and fmic install etc. Didnt see it on my boost gauge (vacuum) because of increased flow i think. On stock smic kit i realy could see leaks, because of bad vacuum.

Your timing is also jumping allot. Same symptons is found when having a bad crank / cam sensor i think. Look it up.
Yea I just fixed my exhaust leak it was bad but the down pipe leak is after the 02 and I noticed my timing is jumping around a lot two and it never did that and I checked for jumping timing but it was good on the cams and that is the only other thing that would make it jump would be the 1g cas it was new but it could go bad when I run the car it gets extremely hot it's the black top cas I will do a full test again to just be safe
 
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