2G Initial start rough idle

[98spyderboost]

Hey all, I just reinstalled my rebuilt head and when I start the car it runs very rough and dies. I did all the procedures with the new timing belt and hardware. Straight edge on the sprockets, made sure the oil pump/balance shaft was in phase, crank timing, etc. I've checked the CAS position. Checked vacuum hoses, and sensor connectors. All the plugs are equally black and slightly wet. The car is completely bone stock. Posting a video below. Any ideas or suggestions beyond what I have checked so far?

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[gofer]

Sounds like the timings off to me, put the engine at TDC and take pictures. Its also possible you've got a VERY bad leak right at the IM so a BLT wouldn't be a bad idea either.
Its easy to mix up the following plugs...

front o2 with cruise control
CPS with A/C condensor
ISC with injector resistor​

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[doubleclutch99]

it sounds like the valves are tapping the pistons. def check the timing . did you replace the balance shaft belts or have you taken them off when you did the timing belt ? the reason i ask is, if you did and accidently flipped that tin piece used for the crank trigger over and then set your timing to that mark then you wont be at top dead center . i know that your's sounds like mine did, and that's what was wrong with mine. it 'll still run but like shit. just a thought

 

[98spyderboost]

Thanks guys. I haven't had time to take pics of the timing. But I am starting to think that's the kind of issue I'm having. It's just hard for me to accept that I did it wrong again even after all the checking I did. I'll get back on it this weekend. Thanks for the plug info too!

 

[98spyderboost]

Well I finally got a chance to recheck everything and found that even though I checked it before the CAS was 180 out I fixed that and now it is at least running much better. But I cant keep it running without feathering the gas and it has a bad miss. Basically doing the same as before but the effects are all toned down by 75% It's much smoother but still not able to keep itself alive.

Here are my timing marks. Keep in mind the crank timing marks are actually on the "T" not one notch off like the pic makes it look. I couldn't get the phone at a better angle

<img src="http://www.dsmtuners.com/gallery/files/3/6/0/9/4/img_20101031_150013.jpg" alt="Timing" /><br>
<img src="http://www.dsmtuners.com/gallery/files/3/6/0/9/4/img_20101031_145915.jpg" alt="Timing" /><br>
<img src="http://www.dsmtuners.com/gallery/files/3/6/0/9/4/img_20101031_145833.jpg" alt="Timing" /><br>

Below is a video of how she's acting now...<br>
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What sensors may cause this issue if they were damaged or bad?

 

[98spyderboost]

OK so I have checked spark and fuel now, as well as checked for vacuum leaks. Nothing. Can anyone tell me if a bad MAF or CAS or Crank sensor would cause this issue?

 

[gofer]

Any CEL's? In that video is that as long as you can get the engine to idle or will it hold idle and surge?

 

[dyetrying91]

hows your compression? That ticking noise is still really loud.

 

[gofer]

hows your compression? That ticking noise is still really loud.

You are correct, that ticking noise is EXTREMELY loud compared to normal. Its typical though to have really bad lifter tick when you replace the lifters until you increase your oil pressure and get some oil up in the head. Since he just installed the head and has been having problems ever since he hasn't been able to go drive it around the block to get the oil pressure up.

You are right though it is pretty loud, I'm just assuming its because of the above.

 

[dyetrying91]

You are correct, that ticking noise is EXTREMELY loud compared to normal. Its typical though to have really bad lifter tick when you replace the lifters until you increase your oil pressure and get some oil up in the head. Since he just installed the head and has been having problems ever since he hasn't been able to go drive it around the block to get the oil pressure up.

You are right though it is pretty loud, I'm just assuming its because of the above.

I don't know man. That really sounds like valves on pistons.

To the OP, I just watched the new video a few more times, and that thing just doesn't sound right. IMO do a compression test, I'm almost willing to bet that you are gunna get some wacky results. Did whoever rebuild your head deck it? Was the block free of imperfections? Did you torque the head down in the inside-out pattern recommended? Lastly, what gasket did you use? OEM?


You could also try taking off the wheel, taking off the bottom timing cover, and cranking the crankshaft over by hand, take out the spark plugs and it should turn over extremely smoothly, if you encounter resistance, that would be the valves on pistons. If all the above checks out, check your coolant temp sensor. That thing causes weird issues if it is loose.

 

[98spyderboost]

Any CEL's? In that video is that as long as you can get the engine to idle or will it hold idle and surge?

That video is starting up and letting it idle it self. I can feather the gas and make it idle at 2k or so and it misses but it dies immediately after I let off.

No CELs. Of course it hasn't had any time actually running long enough to trip one.

Turning the crank with out the spark plugs in is very smooth with no noise or draggin/binding.

The ticking only happens when the RPMs get above 2k or so. But again it dies before the oil is making it to the head, and I'm not about to risk holding the idle for several minutes just to see if the ticking stops. It's really not much louder than the lifter noise I had before the head rebuild, plus I assume the revised VLAs have something to do with that...

The only mod to the head was 2 angle grind on the exhaust valves. No decking, or porting. OEM head gasket. Revised valve lash adjusters. New seals. All other parts are factory. The block was free of imperfections and the headbolts were tightened in order from the center out and torqued using procedure in the factory service manual.

I'll check the coolant temp sensor next. Gotta find out how...
I was also wondering if the MAF sensor could cause this kind of issue if it were somehow damaged when it was off the car. And is there any way I could have put the crank angle sensor on backwards? I thought it was keyed to only go on one way but now I find myself questioning everything.... Thanks for all your help guys, I'm really having a hard time with this!

Compression test shows very solid all across the board. In fact perfect, especially when compared to before I took the head off However when I took the spark plugs out I noticed the #s 1-3 plugs were mostly dry. I could barely tell they were damp at all. Which to me looked like good burn. The #4 cylinder had a bit of wetness at the electrode area. Not a lot, just a noticeable difference. I'm looking through my service manual on testing procedures for each of the sensors... Anyone know of a good DSM mechanic in the Nashville TN area? I'm really at my witts end!

 

[98spyderboost]

Well, all the sensors I could test resistance on all check out. As do the Coils, etc. The only sensors still not tested are the crank, knock, O2, and MAF sensors. And even though the computer was working fine when it went down I'm beginning to suspect it as well.

BTW the ticking has pretty much disappeared. I assume because I have ran the car a few times and the oil has gotten to the new VLAs.

Can anyone tell me if a damaged knock sensor will screw up timing on a cold start? Or if the MAF could possibly do anything similar?

 

[gofer]

Damaged knock sensor only picks up phantom knock killing your timing advance. I'd be more inclined to think its the front o2 sensor more than anything else, the CAS/CPS not working will kill spark on 2 cylinders typically 1 & 4.

Before you get crazy and replace your front o2 sensor check and see if you plugged it into the right connector. Sounds ridiculous but its possible to plug the front o2 sensor into your cruise control, since you pulled the head odds are you unplugged everything.

 

[98spyderboost]

Damaged knock sensor only picks up phantom knock killing your timing advance. I'd be more inclined to think its the front o2 sensor more than anything else, the CAS/CPS not working will kill spark on 2 cylinders typically 1 & 4.

Before you get crazy and replace your front o2 sensor check and see if you plugged it into the right connector. Sounds ridiculous but its possible to plug the front o2 sensor into your cruise control, since you pulled the head odds are you unplugged everything.

doesn't sound crazy at all. In fact I already checked that and double checked it after I read your post... I never took that part of the cruise off and never unhooked the harness from there. But for the sake of diagnosing, I did switch the plugs expecting to see a change because the O2 was now not hooked up to the proper plug. However it acts exactly the same as if it were hooked up properly WTF If the O2 sensor was good wouldn't it act differently when disconnected? Would it not throw a code if it were bad? Or will it only throw a CEL in closed loop?

What do you mean by 'killing fire'? Those cylinders will lose spark altogether? Or they will run out of phase? Because I checked the spark and I'm hot on all the plugs...

Would be nice if it was the O2? Is a wideband plug and play? or do I have to alter anything to get it to work properly? I'd hate to spend the $ on a factory sensor when the upgrade I will have to have for tuning is only a little more...

I just ordered my Open Port 2.0 cable and I have Evo Scan ready to go. I'm new to logging/tuning... Will the datalog info be helpful in diagnosing this kind of issue on a completely factory spec car?

Thanks again to everyone for their input! When this is resolved I think it will be a nice information thread

 

[standard235]

Most widebands have what is called a narrowband simulation output that you can run to the ECU for the factory o2. Just tap into pin 4 on the big connector I believe.

 

[98spyderboost]

Most widebands have what is called a narrowband simulation output that you can run to the ECU for the factory o2. Just tap into pin 4 on the big connector I believe.

Thanks for the info. I'm off to work now. I'll read on it while I'm not busy there. I'm going to pick up an O2 sensor this evening. This will be the first part I have actually thrown at it. I've tried desperately to keep from part tossing but it seems inevitable. I'm still kinda confused over why it hasn't thrown a code yet...

Cross your fingers

 

[gofer]

Most widebands have what is called a narrowband simulation output that you can run to the ECU for the factory o2. Just tap into pin 4 on the big connector I believe.

Pin 4 would be correct if he had a 1g. Its pin 76 (front o2) and pin 75 (rear o2) for the 2g DSMer's.

If the CAS/CPS is bad you won't have spark on cylinders 1 & 4 and typically the car won't start, the results would show after checking spark you'd only be getting spark on 2 & 3. You said your getting spark on all four cylinders so I'm certain the CAS/CPS aren't the culprit here.
Its very possible the front o2 sensor is bad and YES logging software is useful when diagnosing problems as well as tuning. If you must know I think I've used DSMLink more for troubleshooting and chasing down problems than I have for actual tuning, logging software is worth its weight in gold. I'm not familiar with EvoScan whatsoever but if you can get it to log the MAF (Hz), front o2 (V), and coolant temp sensor (F) and check for operation and you'd more than likely find the problem.

When you get a WB o2 sensor you've also got to get a gauge and wire it in properly. Depending on where you want to install it will depend on how in depth the process of getting everything working is. The most pain free way of doing it is removing your downpipe and having a shop weld in a o2 sensor bung, after that all you've got to do is wire it to a 12v power source and ground and it's working.

Personally I'd try and get your EvoScan up and logging so you can troubleshoot this issue without spending any more money. My guess is the front o2 sensor is bad but you won't know for sure without logging it in EvoScan. Depending on how the front o2 sensor or any of the other sensors fail the ECU might not throw a code, thats why your CEL might not be illuminated even though it idles like crap.

 

[98spyderboost]

Finally got my Open Port 2.0 yesterday. Just got it hooked up and logged for a minute while I kept it running by feathering the gas. I uploaded the log I have and linked it below. I just started messing with this so if I didn't log something properly, or if I made it too hard to read or something I apologize. Lemme know what to change and I will do it again. I understand very few of the values Can anyone take a look at the log and tell me what they see that may be obviously off?


Log #1 - First try at logging.

 

[gofer]

First things first you can attach the log directly to your post, no need to use a host because it took 5 minutes to download a measly log file.

Your front o2 sensor looks dead or not plugged in correctly, you didn't happen to plug it into your cruise control plug did you? Triple check! The front o2 sensor voltage should cycle from .8 to .2 volts while your cars idling and in that log I don't see it going over .2v the entire time.

 

[98spyderboost]

Ahh thanks. I'll do that next time.
I checked it again, there is just no way its connected to the cruise. I even switched them again just to be sure and it gets waaay worse when I do that. It wont fully fire in fact... It's also a bran-new O2 sensor WTF
Sooo lets look at that. Forgive my ignorance but what controls the voltage to that sensor? Is it all directly from the computer or is there some sort of regulator in between? Is it at all likely I bought a bad O2 sensor? This issue was not present when I took the head off to begin with.
Just a thought... Years ago there was an e-bay A/F gauge wired in. If I remember correctly it was connected to the wire just outside the computer housing with one of those blue tap connectors... It was removed about 3 years ago though...

I also attached the file to this post just for S&Gs to see how that worked....

 

[gofer]

You've got to let your car get completely warmed up to get a good log, the warmest I see it getting is around 150*F coolant temps and operating temp is 180*. Again the front o2 doesn't look like its cycling since its a 1v sensor it should cycle around .8v to .2v in closed loop but I don't see it happening.

The voltage comes from the sensor itself depending on what your fuel mixture is and sent to the ECU to control closed loop fuel trims. A voltage signal between .1 and .4v would be a lean signal, a voltage signal between .6 and .9v would be a rich signal, and a .5v signal is stoich (14.7:1).

 

[98spyderboost]

OK so today I will do the log again but get the car warmed up first...
So you're saying the O2 sensor creates it's own voltage via reaction with the exhaust gases? Does the ECU enter closed loop mode at operating temp? If the ECU is in open loop what does it use instead of the O2 sensor signal, a preset value? If this is the case then the O2 sensor is obviously not creating an issue at cold start... If it measures that low when it is in open or closed loop, that means I'm running very lean right?(assuming the sensor is functioning properly) Could my MAF be malfunctioning in a way that would lean it out that much?

I'll try to get a log posted this morning before work. If not tonight at the latest.
Thanks again for all your help! I'm learning a ton and finally feel like I'm getting somewhere.

 

[gofer]

If any of the below are true the ECU will enter open loop mode and ignore the front o2 sensor voltage, pulling a preset AFR from fuel/timing maps.

• Throttle position too high (varies by RPM)
• Airflow too low
• Coolant temp below 51*F
• Coolant temp above 228*F
• The O2 sensor does not switch around 0.5v for over 128 seconds while running in closed loop mode. In that case, the ECU will lock itself in open loop mode.

Your o2 sensor is measuring a LEAN value, from the log I'm seeing .1v, that means the ECU is trying to make things rich. Do you have a WB gauge, if so what are the average displayed AFR's while its idling?
Your MAF is working just fine, I can tell by viewing your log that all three signals it produces look normal. Those three things are Baro, AirTemp, and in your log it looks like MAP should really be MAF because of the values being shown. The only thing that doesn't make sense by looking at your log is your front o2 voltage to be honest with you.

Another thing you might try is looking at the ECU harness and finding pin 76 where the front o2 signal gets to the ECU. If theres a hacked wiring job there its a possibility the ECU isn't seeing the voltage the front o2 sensor is producing.

2g ECU pin out

 

[98spyderboost]

Great info. Thank you very much. I'm attaching the last log I did I got it to 183 or so before shutting off. It took me a minute to find the sweet spot but i got it to idle for a few minutes... Are there any other things I should be logging? And no I don't have a WB gauge. What in the world would be making my 02 do that? I just checked the heater side resistance and it showed me 110 ohms I believe. I cant really remember I just checked it for continuity.

 

[gofer]

It appears the front o2 begins to cycle a bit around the 68 - 73 cells in your log, then it drops to .1 and pretty much hangs out there the rest of the time your logging. If your certain you've got ZERO boost/vacuum leaks, more so in the TB and IM area, then I can only assume your o2 sensor or wiring to the pin 76 of the ECU is faulty.

As far as logging more things go I'm not sure what else you can add to the log, do you have a MAF loggable value?