My cap and rotor had about the same amount of miles.

 

anyone?

 

anyone see anything that looks wrong?

 

The first thing I notice is the timing. There's no way at idle the spark advance should be 30. I would expect to see closer to 15. 36 when it's all in is ok. However none of that should be giving you the problem you have.

The next thing that stands out is the IAC counts. They should be around 40. But that may just be an indication that it's running so poorly the PCM is attempting to keep it running.

WOT O2s mean nothing since at WOT the PCM goes into open loop and ignores them anyway.

What you DON'T have in your readings is the O2s or the fuel trims at idle. I would like to know what they are showing.

Also, you alluded to it "missing" in one of your earlier posts. If you have missing, obviously that is the place to start. It would be making you run rough, run rich. The PCM might possibly interpret that as running rich and pull fuel. Causing the other correctly firing cylinders to run lean and the hole running problem gets worse.

If you still have miss-firing then you should immediately find any dead cylinders. This can be done several ways but my fave is to check header primary temps with an IR thermometer. Start from dead cold in the morning is good. Have someone else fire it up and watch the temp rise of all the tubes quickly. The one(s) that lag FAR behind in temp rise are the suspects.

Check those cylinders for plug wire problems or plug problems. Swap a good cylinder if you need to.

If all that is good. Move on to the O2 readings and the fuel trims. Be sure the O2 readings are sweeping between around 100mv and 900mv. If not, there is the place to focus.

Hope that helps
Dave

One last question. Does the engine run good until it warms up or is it crappy from Dead Cold as soon as it's fired up?

 

worst when closed loop, better at wot, and even better at open loop, I'll get my dads ir thermometer and see if i can find something out. I'm not sure when i can get back on the scanner tho, i'll try to do it soon because the weather is great and i want to drive my car BAAAD.

thank you for your fast response.

 

As far as the timing at idle... its obviously not a stock tune (18-22deg), so who knows what they did to it when they tuned it. Same with the IAC counts.... they may be high because the PCM has to keep the CC306 idling. The cam is pulling about 10"Hg and that's on the low side.

While the O2's aren't used for control at WOT, the readings can be meaningful. Recognizing that the stock, narrow-band O2's are not necessarily all that accurate at the richer A/F ratios used at WOT, the fact that there is a 150mV difference between left and right bank is very significant, and may indicate a severe lean condition on the left side.

The PCM interprets misfires as running LEAN and adds fuel. The unburned fuel, and unburned air go out the exhaust valve, the O2 sensors see the unburned air (they can not "see" fuel, only oxygen), O2's read lean, and the PCM adds fuel the engine doesn't need, and the 3 cylinders in the bank that aren't misfiring run rich.

I'm still puzzled by the numbers you are reporting as "knock".... (knock idle = 40, knock WOT = 74). Are these actually the "knock count" numbers? The PCM calculates knock count numbers, based on the engine operating parameters. The knock count field will increment upward until it reaches the maximum value that fits in the field, then resets to "0" and starts to move upward again. It isn't unusual to see knock count increase significantly during startup. And, by then selves, the numbers mean nothing. And since you have knock retard tuned out, they can not cause any.

 

heres the readings i got today

All are at 875ish rpm in open loop:

Lo2 mv 391 Ro2 mv 565
L Blm 128 R Blm 128
Af learned No F cell 16
Tps v .62 Throttle 0 %
L Bpw (ms) 4.1 R bpw (ms) 4.1
Airflow ms sec 10.5-11 Iac pos 95-115
Map v 2.92 map hg 19.0
Baro 4.82 Baro 29.3
Knock retard 0 Knock 114
Ign v 12.1 cc cycle 0
Egr duty 0

All these readings are closed loop at 925ish rpm

left o2 707 Ro2 890
Iac 83
Map 18.1-18.8

all other readings were the same as open loop

when taking off my tb i found a that the 90 going into the tb and coming from the passenger side valve cover was cracked bad, so there would have been a vacum leak there for sure. i just got some tubing to fix it.

i am about to test my iac via a multimeter its really gunked up.

 

as for the knock being crazy high, i don't have it plugged in, its zip tied onto some trans tubing. The sensor broke and it won't plug up like it should, so i left it off. Knock is tuned out so i didn't bother replacing the sensor. Is this why its so high?

 

i just took out the old iac module and replaced it with another i had on a tb thats been sitting outside, made it worse. so i cleaned the old one and put it back on. it was better but still missed/surged around 5000 rpm.

think i need a new iac?

 

just drove it again i think it runs fine in open loop, then messes up in closed loop. is this a possiblity?

 

A single frame of data is not very usefull. In closed loop, your O2 sensors should be swinging wildly back and forth over the range of 0xx - 9xx millivolts. The PCM checks the O2 readings approx. 9 times per second. A single reading has absolutley no value of any kind. They don't even have to be the same - left and right - because each bank of the engine is controlled independantly.

No matter how you slice it, your MAP is too high (= vacuum is too low), but may be the combination of the CC306 and the tune. The IAC counts are high. Is it possible you have dirt in the IAC passage in the throttle body? Have you cleaned the passages?

No, that is NOT a significant vacuum leak. The line from the throttle body to the valve cover is not a vacuum line. The port for that connection is IN FRONT of the throttle blades. The purpose is to flow clean, MAF measured air from the air intake track to the valve cover, so the vacuum from the PCV valve can pull the clean air through the crankcase and lifter valley, to clear the blowby gasses out of the engine. Is just means a small amount of air was probably being pulled in through the cracked elbow, and that air was not measured by the MAF and included in the A/F calculation. But that will not cause problems. Many people add a "breather" to the valve cover, and that causes the same air bypass of the MAF, and causes no problems at all.


Did you carefully read what I wrote? The "knock" you are referring to appears to be the "knock count".... it is a parameter calculated by the PCM, based on engine operating conditions, and has little if anything to do with the knock sensor, or with your knock sensor being programmed out. It is ENTIRELY NORMAL for knock count to increment up slowly, particularly every time you start the engine.

Entirely possible that you have a problem that is made worse when the PCM goes into closed loop. Since you have a scanner, get the long term fuel corrections (BLM's) for Cell 16, and as many other cells (you have to drive the car at varying combinations of RPM and engine load - MAP - to move the PCM through the other 15 active cells). If the BLM's are maxed out, and they are responding to a "false" O2 reading, its possible that its going to run worse in closed loop, when the short term corrections are active, and are able to add or subtract huge amounts of fuel from the A/F mix.

 

so from here i need to make sure the passages for the iac are clear, and get some readings on the fuel trims. BLM figure with the corresponding cell. There will be 16 total cells, but to get them to pop up on the scantron i have to drive it at different percentages of throttle and rpm.

I am using a guys scanner at his shop so i have limited experence with it, it had a section to make a movie (record the data). would it be best to turn this on and drive it at different loads and rpm's then review it and look for the 16 different cells? or is there a way to convert them to a computer image and just put the recording on a spreadsheet?

another thing i just realized is it seems better in enrichment mode, it still has the problem but not nearly as bad, so would that mean the fuel trims that the computer is adding short term is complicating the issue?

So it is worst when closed loop, better at wot, and even better at open loop.

Thank you for your time.

 

Back driver side (7?) cylinder is not firing primary wasn't even hot. from here i check for spark, then fuel correct?

 

The are 18 cells total. 16 is idle, 18 is an open loop load cell (calculated from the other cells) and is also used at times for PE mode. 17 is a calculated cell that is used for decel. 17 and 18 aren't that important, but 18 will give you a weighted average of the other cells. Just make sure you don't clear the PCM before you record the data, and make sure the engine has a few hours drive time on it, or you will not get fully developed BLM's. Cells 01 through 15 are the ones you want to try and record.

If #7 is not firing at all, you need to determine whether it is fuel, spark or something mechanical. A 'noid light set would tell you if the injector is being given the signal to fire (ground) from the PCM. Swapping the injector to another cylinder will tell you if its the injector (misfire follows the injector) or spark/mechanical (misfire stays on #7).

 

pulled it and it was getting spark. i swapped in a plug and it ran great of 2 minutes then gradually went back to how it was before. I'm thinking its in the injectors, so i'm going to do what you said and try to come up with a noid light, then if its getting signal swap it to a different cylinder like you said.

How can you tell what cylinder is misfireing tho, the only reason i found it on 7 is because it was completly dead and the primary temp was staying the same. Just swap out the injector and see if that one eventually stops firing also?