Erratic Idle Surge & Knock

[Zerocygnal]

This car ran flawlessly the other day, the next it was mad idle surge, never falls below 1k. I had already replaced the BISS O-ring while it was running fine, since it had never been done. The next day...I don't know what happened...my pocketlogger was showing some crazy knock almost anytime you pushed on the pedal. I replaced the spark plugs (BPR7ES@.28) but they looked okay, they had a slight whitish tint to them but otherwise looked clean. NO fluids in the combustion chamber. This problem exists while the engine is at cold and normal operating temps. Vacumn is 17, all new gaskets. The engine even sounds different..louder.

On another note at idle when it surges up the injector p/w and duty cycle both go up, when the surge goes down both of them hit 0. It's seems to be dumping fuel, then cutting it off completely, and then dumping fuel again repeatedly. ISC readings seem a little flaky... it never hits 120...then again my TPS never went over 50% cause I didn't want to push it with that kind of knock. If you try to maintain any speed at say 35mph in 3rd gear it bucks...bad. That is to say, not accelerating or decelerating.

Knock count hits 42 anytime you put a load on the engine. It's parked...not driving it till it's fixed.

Please give any suggestion you can think of.
If you want the logs I'll put them on my site and link to it. Nothing looks out of place on them...all of the readings are consistent with the wacky idle.

NEW:
Fuel Filter
Spark plugs
Plug Wires
BISS O-Ring

 

[Zerocygnal]

Anyone...? An idea..? This is my daily driver...any help is appreciated.

 

[echo]

sounds like you might have a small vac leak somewhere. vac is suppose to be around 20-21 if i am not mistaken.

 

[Zerocygnal]

Originally posted by echo
sounds like you might have a small vac leak somewhere. vac is suppose to be around 20-21 if i am not mistaken.

base is 17 at idle and 21 to 22 on heavy deceleration while in gear. thanks for your response though! I need all I can get. I do think I have a small vacumn leak somewhere however..but it was there before these problems started happening.

I don't have the EGR blocked off and I have no emission system equiped. I have the blockoff plate for it...I just haven't put it on because I am putting the car down next month for a total refurb. New paint down to the frame inside and out. Intake, exhaust & manifold, built engine with total powedercoat, total rework on the suspension. I was just going to do it all at the same time. I might go ahead and install the block off just in case until I'm ready to begin. Can it cause these problems?

(I have "heard" it can...just want to be sure...)

Thanks again.

 

[ltvarney]

if it sounds louder maybe it's phantom knock setting off the knock sensor from the additional noise. since you've got the blockoff plate that's going to be the easiest and cheapest thing to try first. if that doesn't do it, maybe you're running lean due to the fuel system? my fuel pressure regulator took a dump, but i think that normally makes you run rich like it did me, so maybe fuel pump or fuel filter clogging up? has the car been any harder to start?

I think your DSM is telling you it wants the built motor sooner than you were planning on installing it I'd get the issues sorted first before doing the swap in case it's not the motor itself causing the problem.

 

[Zerocygnal]

I wish it was phantom knock...if you press hard enough you can hear it. I will probably install the blockoff plate tommorow, only thing I can think of. Car starts fine, catches like a new car on a .25 second turn of the key. FPR huh? I'll test that...Or...I could always install the A1000. Fuel Filter is new but it's not impossible. Is it possible for the fuel pump to be "partially" working? Usually they either work or they don't.
Perhaps the wiring to the pump is corroded from all the ice and salt?

I agree, I'm so ready to start this project...gotta wait till I'm done closing on this new house. Then I will have...MY OWN GARAGE AGAIN!

 

[kristmen]

Do you have any lifter tick?

Let me tell you what my cars doing.

It ran fine for while then I started to get a slight lifter tick. I didn’t think much about it at the time I prolly let it go more then should have but anyway I kept driving it like that.

I noticed my car was running really assy one day. It would bog down and have no power but I couldn’t figure out what it was. I wasn’t getting any CEL or anything I tried changing my plugs and given it a tune up but nothing helped.

I bought a PocketLogger and when I hooked it up I noticed I was maxing out the knock gauge on it, 40%+ knock.

When I first start my car its really ####ing bad. I would press the gas and the thing would get knock, bog down and the timing would retard to almost 0 and if i would give it a lil more gas it would even backfire. The tone of the exhaust system was sorta loud and hallow. Letting off the exhaust under these conditions would cause the BOV to make a louder then normal WHOOSH sound too. Well I don't know if it was louder but it didn’t sound normal. Almost like it wasn’t boosting right due to the timing of the valves being changed due to the ECU retarding the timing.

If I let off the gas the knock reading would go away and the timing reading would go back to normal. Once I would press the gas again it would normally come back within a few seconds. Almost makes the car not drivable.

Now as far as what’s going on with my car I've somewhat narrowed it down to a bad lifter. Friend of mine had lifter problems too and he ran some tranny fluid and water threw his intake to burn off some of the carbon build up. Made the tick go away so I tried that not even thinking it had anything to do with my knock problems. I was just trying to get rid of the lifter ticking. After doing this guess what else was gone.. The knock, bog down, and timing being retarded to hell. After about a week the tick faintly returned and I was getting knock again. Couple more days the tick came back worse and the knock levels got worse too so I ran more tranny fluid and water threw the intake. Knock gone again..

I don’t know why but it seems that the knock sensor is picking up that lifter tick and thinking its real spark knock and responding by retarding the timing to attempt to save the engine from detonation.

I don’t know if the knock sensor has gone bad or what. My friend tells me eather a knock sensor works or it doesn’t. Someone else told me they can go bad over time and that it might be dieing now. Not sure who to listen to.

As a test I suppose one could disconnect the knock sensor and see if the knock problem goes away. I don’t mean unplug it btw. By default the engine would retard the timing if you disconnected it. Unhook it from the back of the engine, put some foam padding around it, put a plastic baggy around it, zip tie or tape it up and stick it somewhere it cant pick up any noise and go for a drive. If your car seems to run normal that was prolly the problem. If you get real spark knock you will hear it. It will sound like diesel knock. If you hear that shit let off the gas quick.

I personally haven tried that yet but I'm lazy sooo...

Not sure if any of my rambling helps but it gives you something to check.

 

[Zerocygnal]

After going out a minute ago and reluctantly starting it. I believe the knock sensor. Diesel type knock. I'm not gonna rev it... Pocketlogger...have you ever seen timing hit -1!? Damn that's scary.

My lifters have fortunately never ticked, but I do have to ask. If you put hydraulic fluid in the intake, what part of the intake did you introduce this to? If you put it in through the throttle body is it possible that you may have partially cleaned it, and perhaps that made it run right breifly?

Now that I think of it...this started on the first day after it hit over 50 degrees here. Like I said..that day it ran beautiful, parked it, next morning ran like shit. Man...I hope no one pissed in my gas tank. Damn..now I've gone and made myself paranoid.

Thanks for the long reply and the time you took to give examples and go into detail.

 

[Zerocygnal]

Well I installed the EGR blockoff plate to eliminate the possibility of a leaking, disconnected EGR. No change, it still runs very rough...I'm still wondering about fuel contamination..

 

[LandoAWD]

check the timing as well.

 

[Zerocygnal]

shifts between 5 and 7 at the rough idle.

 

[ltvarney]

I've heard of fuel pumps being bad to where the pump wasn't able to supply the necessary fuel. Usually I think it results in the car not starting though. This happened to my neighbor. She was getting fuel. Just not enough. Maybe yours is borderline? It's hard to believe you would be detonating at idle like that. Maybe there's a bad injector causing just one cylinder to run lean.

You could always call a Mitsu dealer or DSM shop and explain the problem and ask for suggestions. Just trying to throw out ideas here, I know how it sucks when your daily driver acts up.

 

[LandoAWD]

Originally posted by Zerocygnal
shifts between 5 and 7 at the rough idle.

Okay, so you have timing that doesn't stay set. Maybe do a t-belt swap and change out the pulleys and tensioner.

 

[Zerocygnal]

I'm thinking about this fuel pump thing too. Should I just check the pressure, or do I need to know the volume? I did test the injectors using the injector disable test...when it shut off...damn you knew. So those are working..how well I don't know. It's not knocking at idle over 4 counts, only when you press the pedal does it hit 42. With the pocketlogger it's always seemed to jump between digits like that...i checked it without shorting the diag terminal too...so that probably caused that. I just replaced the t-belt, b-shaft belts, tensioners and waterpump 1 month ago, the tension is still within spec. I did notice something with 2 different logs I had...When it was running good I noticed the ISC was at 80 or so at idle durring norm op temperature. However...now it is 38 and even bottoms out to 0. I'll have to test that when I get home with the ohmeter. Thanks for the suggestions Lando and Itvarney!

 

[LandoAWD]

Hope you get it worked out!!

 

[Zerocygnal]

Looked over the logs again...didn't notice it before and I'm not sure how. The O2 sensor isn't doing a damn thing. It sits at 0.02 and if you rev the engine it just stays there. Tested it off of the car...dead as a doornail. Funny thing was..when I ran the engine for awhile without the O2 sensor plugged in...it never threw a CEL. Thanks for your help guys!

 

[MattnGsx]

Originally posted by Zerocygnal
The O2 sensor isn't doing a damn thing. It sits at 0.02 and if you rev the engine it just stays there.

So did replacing the o2 work?

Your car has only a front o2 right? I have the same exact problems as you. Ive replaced my front o2 (looked ok) Put diffrent injectors in (used but caused a improvment a bit?) New fuel filter, turbo. Still runs the same. THough now i through a p0170 code fuel trim. Car kills sometimes, and has to sit before i restart too.

Going to replace fuel pump today, figure out how to test injectors. Replace fuel filter again (i bent the filter putting it in, Plus the flow bolt on the fuel filter don't line up with the hose, would this matter?)

I also think my car has a gasket leak some where because the car will whistle (like playing a coke bottle). This drives me nuts, feals like it runs on two cylinders. Oh yeah ive replaced to plugs and wires too...

Any Ideas???

-Matt

 

[MattnGsx]

btw it did this before i replaced any fuel componets and the turbo. Its been a on going problem for a while that i've been trying to figure out!

-Matt