P0135, and P0306 98 Lumina 3100SFI

[dodgethis]

Guys, ran into a problem when I was heading out to work during the morning. The car immediately ran rough, and soon after check engine light started blinking. I have found out after having it scanned it is P0306, so Misfire on Cylinder 6. I wanted to ask, do we have a write up on how to diagnose a bad coil pack? Looking at the coil pack, is the metal stubs the secondary side? Also, how do we test for a bad ICM? I have used the search button, but haven't found exactly what I'm looking for. I read somewhere the coil pack should read 0.1 ohms?, again I could be wrong.

 

I scanned the car again, and P0135, Bad Oxygen O2 Sensor Heater Circuit Malfunction (Bank1, Sensor1). Is O2 sensor in the engine, not after the CAT correct?

 

 

I have already ordered new plugs, wires, and pcv. Will also order up a new O2 sensor.

 

Again, thanks guys!

[RobertISaar]

with the coilpacks, the side that slides on the ICM is the primary side. most i've tested end up around .3 or .4 ohms for a good primary reading. secondary side(plug wires snap onto) is in the 5,000 range IIRC.

 

assuming you have an easy way of scanning it again or clearing codes, swap the plug wire from cylinder 3 to 6 and 6 to 3(essentially, on that coilpack, switch the wires). being waste-spark, assuming all is well, nothing should change. however, if the misfire now happens on cylinder 3 and 6 is fine, that implicates the coilpack or ICM. i've had half of a coil fail before and this is how i found it.

 

if the misfire stays on cylinder 6, expect those plugs and wires to fix it. with a 60V6, cylinders 5 and 6 are always the roughest on the spark plugs, so it wouldn't surprise me if those two plugs look scary compared to 1/2.

[dodgethis]

with the coilpacks, the side that slides on the ICM is the primary side. most i've tested end up around .3 or .4 ohms for a good primary reading. secondary side(plug wires snap onto) is in the 5,000 range IIRC.

 

assuming you have an easy way of scanning it again or clearing codes, swap the plug wire from cylinder 3 to 6 and 6 to 3(essentially, on that coilpack, switch the wires). being waste-spark, assuming all is well, nothing should change. however, if the misfire now happens on cylinder 3 and 6 is fine, that implicates the coilpack or ICM. i've had half of a coil fail before and this is how i found it.

 

if the misfire stays on cylinder 6, expect those plugs and wires to fix it. with a 60V6, cylinders 5 and 6 are always the roughest on the spark plugs, so it wouldn't surprise me if those two plugs look scary compared to 1/2.

 

 

Thanks Robert! will report back.

[RobertISaar]

GM states 5,000-10,000 as the acceptable range for secondaries.

plug wires show ~200 to ~670 ohms per inch of length.

[dodgethis]

GM states 5,000-10,000 as the acceptable range for secondaries.

plug wires show ~200 to ~670 ohms per inch of length.

 

Well report back what I have found. I have not checked the resistance of the wires, however found the ICM was 3.5 ohms, and as for the coilpack from left to right facing the windshield: 5/2 = 5.88kohms 3/6 = 5.96kohms 4/1 = 5.98kOhms. I also checked the Oxygen sensor, and found continuity on the right two top and bottom pins. I was reading 5.5ohms. Nothing seems out of range. What is even more interesting, is my code for the oxygen sensor, is no longer showing up. I have swapped the Cylinder 3 and 6 wires. We will see what happens.

[dodgethis]

Alright, just an update. Got off from work, got into the car, and had another misfire. After scanning the code It had the existing Cylinder 6 misfire. RobertIsaar, thanks for the help! I think we can agree that it the spark plugs, and time to tune up. I'll keep an eye if it still occurs. I would then think it may be the injector on the way out.

[dodgethis]

Well, Things have became interesting since I have tuned up the car. So far I have replaced, spark Plugs, wires, and PCV. Soon will replace the fuel filter. However, the Misfire symptom has not gone away. What is interesting is as soon as I drove the car with new plugs, I am now receiving Cylinder 3 misfire. This will change when i swap wires between 3 and 6. It misses bad when the car is cold, and just starting up, but after on the road for a while, the car warms up, and the missing goes away. The check engine light stops blinking right after this. I can then check for codes and so far its either Cylinder 3, or 6 depending if i swapped wires. Going back to Rob's suggestion, I may swap out the entire coil pack after ohming it out with a used one and see what happens. Other than what I may do, does anyone feel it "could" be a bad fuel injector? Its a amazing I keep coming back to Cylinder 3 and 6, but no other one. I will say this, after tuned up and clearing the codes. I originally received a P0300 or Random misfire, but after driving it it went to Cylinder 3.

 

Im open for thoughts and suggestions. I am running out of ideas.

[RobertISaar]

swap the 3/6 coilpack with the 1/4 or 2/5, see if the misfire follows it?

[dodgethis]

swap the 3/6 coilpack with the 1/4 or 2/5, see if the misfire follows it?

 

Stupid question, but when you swap the coils around, one can keep the wires connected and move them? 3/6 coil stays 3 and 6, just in a different orientation on the coil pack correct?

[RobertISaar]

..... no, assuming i'm reading that correctly.

 

there are 3 pads on the ICM that the coilpacks sit over, you'll probably see little indicators on the ICM itself for 1/4, 2/5 and 3/6 depending on what position you are looking at. you can put either of the wires listed for the spot on either terminal of the coilpack that sits over it, but you cannot put something like wire 1 on anything other than the 1/4 coil position.

 

think of it this way, the coilpack is relatively dumb, it just creates a spark when the ICM tells it to, the sequencing is all done by the ICM though, it needs the correct wires on the correct pack, regardless of how the pack is labeled. if not, then you'll get stuff happening like a spark happening on a cylinder right as the intake valve opens and sending a fireball through the throttlebody.

[dodgethis]

..... no, assuming i'm reading that correctly.

 

there are 3 pads on the ICM that the coilpacks sit over, you'll probably see little indicators on the ICM itself for 1/4, 2/5 and 3/6 depending on what position you are looking at. you can put either of the wires listed for the spot on either terminal of the coilpack that sits over it, but you cannot put something like wire 1 on anything other than the 1/4 coil position.

 

think of it this way, the coilpack is relatively dumb, it just creates a spark when the ICM tells it to, the sequencing is all done by the ICM though, it needs the correct wires on the correct pack, regardless of how the pack is labeled. if not, then you'll get stuff happening like a spark happening on a cylinder right as the intake valve opens and sending a fireball through the throttlebody.

 

Understood, Well here is where I'm at and what I have done so far. When I started the car in the morning, I checked the codes, and now the Cylinder 3, or 6 misfire code has now been replaced with P0300. While its a random misfire I don't know which plug to pull. So I went to the junk yard and pulled a whole coil pack from a 98 impala with a 3100. I ohm it out and it was within tolerance. I swapped coil packs and still getting the same result as before. P0300 is the only code I am receiving. Originally I had NGK TR55 in the car, pulled those out because of the original misfire on Cylinder 3 and 6. So I have put in new plugs and wires. The new wires are Delcos, plugs are NGK TR55GP. I have gapped the plugs at 0.060 inch per Haynes.

[RobertISaar]

P0300 can be caused by so many things...... there is a 30-step diagnostic process just for that alone. i could post it, but depending on what tools/equipment you have on hand, it may not be of much use.

[dodgethis]

P0300 can be caused by so many things...... there is a 30-step diagnostic process just for that alone. i could post it, but depending on what tools/equipment you have on hand, it may not be of much use.

 

I'll look for that step procedure, I have the True Factory Chevy lumina Manual (3 books). One other thing I have done is, Per this website

http://easyautodiagnostics.com/gm_coil_pack/gm_coil_packs_3.php

I have pulled each Coil Module off and verified 12VDC power is shown off the #2 post. ICM checks out good. Resistance on the Secondary side was around 55kOhms for each module. I'll report back if I find something or find a solution. Thanks again Rob for the help!

[dodgethis]

I regret to mention this but I took into the shop. Hopefully after $100.00 I can find out what it is and decide if its something I can handle

[dodgethis]

OK, just after the car was taken in. I was later told that the only thing wrong was a spark plug wire was not seated correctly to the coil pack. I was told that one of the wires had to be spliced and it ended up fixing the problem. The car is running smooth now, but I'm blown away about the "splicing the wire" part. When I open the AC Delco box of spark plug wires, I found one wire without a boot, and it was tied in a knot. I bought it from Rockauto so I don't know if it was done that way before it was sold, or from the Ac Delco factory. Oh well whatever. It runs.

 

By the way, I replaced the missing boot from the old wires, and put on the new wire. I did remove knot before I installed it on the car.

[RobertISaar]

i really don't know what to think about a spliced wire..... maybe cam position, 24X crank or 7X crank?

[dodgethis]

Nope problem not fixed. Car still random miss-fired when cold, and it slowly stopped misfiring when it warmed up. I am still leaning toward a bad injector. If I pull off the Plenum, do I need to replaced the bolts? I thought, or read somewhere the bolts were Torque to yield, is that true? Can i reuse the bolts if they are not. I would most likely grab a new gasket for it, if necessary

[RobertISaar]

i seem to remember the LIM bolts being TTY, but i don't think the UIM bolts are(since they don't have an associated torque+angle specification). i will state that you need to be very careful torqueing them down again(18 ft-lb), otherwise a cracked "ear" on the UIM is a possibility.

[rich_e777]

You can reuse UIM and LIM bolts, just clean them up real good and put some sealant on them. Its the cylinder head bolts you defiantly DO NOT reuse.

[dodgethis]

Thanks guys, will give it a shot

[Joshua Shaw]

Any news? Im curious.

[dodgethis]

Any news? Im curious.

 

News update, So when I took the car to Firestone to see if they could fix the issue, they originally thought it was a "splice" issue with the spark plug wires. Well they thought they corrected and I was told to come pick it up. Well, Low and behold the car started missing again. I took the car back and they looked at it again. I got a call the next day saying firestone didn't see a problem as the car was not misfiring. (Which is hard to believe because it does it when its cold, and rarely straightens out when it warms up). I pick the car up and on the paper work they state I had good compression (150 to 155 don't know units), and Fuel pressure was 41PSI key on. So I am reimburse the 115 dollar diagnostic fee (evidently they couldn't figure it out), and I go home. The following day I wanted to pop the hood and realized they had slammed the hood so hard the un-latch mechanism wouldn't let go of the hood (not in the car, the outside latch). I again went to firestone and complained and they couldn't get hood open. They continued to suggest me to come back and they would fix it. I haven't gone back needless to say.

 

So here is where I am right now. I have removed the plenum, and with it came the throttle body. They both need to be cleaned. I can see all the injectors. I want to ohmn them but don't know how to take the connectors off. Should I just pull the rail up, and off to better get at the injectors? I can see a metal clip under the injectors, do you take a flat head and pry back on that clip to let the connector pop off the injector?

 

Also, I was gonna get at the Oil Drive pump and replace the 0-ring, I need to find Schurkey's info on the correct o-ring. Search function wont be hard.

 

Lastly, Cleaning up the plenum, and throttle body. A bunch of of Carburetor cleaner sufficient to knock that out?

[RobertISaar]

if you have the plenum off, you probably see that paperclip thickness retained on the end of the injector plug connector? should just have to press lightly on that and pull and then they pop off.

[rich_e777]

I would recommend removing the entire fuel rail assembly to make things easier. Yes that metal clip must be removed and a small flat screwdriver or pick works. I want to say a good injector will read about 15 Ohms but I could be wrong, I don't have me book with me ATM. Make sure you replace ALL the O-rings on the injectors as they will more than likely be stiff and could make resealing the injectors a pain if you reuse them, so don't. But they only come 4 to a pack.

 

IIRC a oil pump seal from a older 70's era Impala was the paper one to use and I cannot recall the regular O-ring size. Also get some permatex sealant #2 and put along the bottom of the lip at the top of the shaft once removed. Also put some engine oil on the teeth at the base of the shaft to make re-installation a little better. Hopefully your coolant fitting to your thermostat housing is the threaded kind and not the pressed in kind or you will have all kinds of fun.

[dodgethis]

if you have the plenum off, you probably see that paperclip thickness retained on the end of the injector plug connector? should just have to press lightly on that and pull and then they pop off.

 

Thanks Rob, once I pop that clip, I have read how other have ohmn the injectors, and have got confused on doing it. To set me straight, Just simply checking resistance on each injector correct?

 

Found Shurkeys image about the oil drive pump: http://hbassociates.us/Lumina_Oil_Pump_Drive_01.JPG