chawkins2001

A quick history, my car has been running terribly since I got back from Timmayfest. Things that were changed before this misfire dilema started:

• O2 sensors changed and wires extended
• Kleeman tune uploaded to permanently turn of rear O2's for emmissions puroposes (passed emmissions finally)

Right after those two changes, I filled up with a new tank of e85, and headed out to caffeine and octane July 1. I climb into the throttle from 1/4 throttle, and the car breaks up badly, hiccups with the CEL flashing, multiple engine misfires are the result and CEL is now permanently on.

I think maybe my plugs are bad, and pumped bad E85, so I change to a one step warmer plug per Bruce's recomendation, thanks brotha, and gap them to .032

I also had to wait a month for our local gas stations to get E85, so I drained out the old gas, and filled up with a new tank of the corn. These are the list of misfires:

Current Fault Log 07/01/12
------------------
P0305: Cylinder 5 Misfire Detected
P0306: Cylinder 6 Misfire Detected
P0300: Random/Multiple Cylinder Misfire Detected

Pending Fault Log
------------------
P0305: Cylinder 5 Misfire Detected
P0306: Cylinder 6 Misfire Detected
P0300: Random/Multiple Cylinder Misfire Detected

Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
ECU reports no other fault codes logged

End of report.



Current Fault Log on 08/05/12
------------------
ECU reports no current faults

Pending Fault Log
------------------
P0507: Idle Control System RPM Higher Than Expected
P0304: Cylinder 4 Misfire Detected
P0307: Cylinder 7 Misfire Detected
P0308: Cylinder 8 Misfire Detected
P0300: Random/Multiple Cylinder Misfire Detected
P0303: Cylinder 3 Misfire Detected

Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
ECU reports no other fault codes logged

End of report.

The car idle is non-existant, it hunts from 500rpms-2000rpms and is breaking up under any type of boost.

What do you guys think is going on, a leak test was done to see if there are any vacume leaks, it came back negative. Correct me if I am wrong, but a tune cannot all of a sudden get out of whack can it, nothing on my tune was changed from Timmayfest, yet all these problems have arised.

Any help is appreciated

jmb614

Sorry to hear about this Craig. I've had the p0300 and associated misfire codes before. I know you mentioned that you had replaced the O2 sensors, did you replace the front sensors as well? If so, were they direct replacements and not universals?

Once I had changed my front O2 sensors all codes went away and the car has been running strong ever since.

chawkins2001

Only one sensor was bad, and I am not sure if it was a front or rear. Does it matter of they are direct vs universal?

cij911

A tune does not change.

Sounds like it is a bad O2 or wiring issue. Although if you disconnect the O2s the car should just run rich by default.

What AFR are you seeing at idle ?

What injectors are you using for e85 ?

e55amgrocket

I would start with checking the 02's. I had the misfire problem for awhile and after chasing it (replacing plugs,wires,swapping coils and eventually replacing coils) it started using coolant and ended up being head gaskets. It would do all the things you are talking about.

komp55

I learned more about O2 sensors in our cars than I ever wanted to know when I was chasing down what turned out to be a failed O2 ground circuit in the ECU. If your front sensors aren't functioning correctly, or are mis-wired, the ECU will definitely throw codes.

Bosch offers three replacement O2 sensors for our cars. I wouldn't even consider other brands or off-brands for this part. The universal sensor is Bosch part number 15733, and can be used in the front or rear. They have a decent length of wire attached and can be customized to the fit you need. The key to using this universal sensor is to 100% be sure to use the connector block that is supplied with it to get a waterproof, with no possibility of cross-wired or shorted connections. Contrary to what some may tell you, soldering the O2 signal and ground wires is an invitation to issues down the road. The universal sensor kit can be bought for around $50 each.

If you want exact fit replacements that plug right into the factory engine harness, the go Bosch part number 16272 in the front or 16328 in the rear. Note, however, that if your rear sensors are extended, the 16328 sensor will still need the extension. I extended mine for my MBH header install with two universal kits (15733), using the supplied connector blocks, and they have been trouble free ever since.

If you're running on suspect O2 sensors, I'd start there, particularly if the rear ones were extended by a means other than using the Bosch connectors. Wouldn't hurt to install front replacements while you're at it too.

chawkins2001

Thanks for the comments fella's, this is some good information here. Before this happened, my idle A/F would bounce around between 9-10.

I am on 1000cc injectors for e85.

jmb614

I replaced all four of my O2 sensors, I used direct fit Bosch for the front (part number listed by Komp55) and universals for the rear with some 90 degree adapters from Bruce, since I needed to extend them.

When both of my front O2's went the car did not know how to fuel itself. It would idle rough and bounce around the wideband between 13-15 at idle. LTFT shot up to +15 to +21 on both banks and the car would buck and **** and moan under any kind of boost because it appeared to revert to an extremely rich map under throttle bouncing between low 9 to mid 10 AFR.

cij911

Idle AFR looks good (pre issue)

It really sounds like it is your O2 sensors. Also I was not aware that Kleeman did e85 tunes and as you know the fuel needs are very different and they would need to scale the injectors properly (but I know you know that)....

chawkins2001

Kleeman did not tune my car, BIP did. I will definitely check my O2's as suggested.

Worth the wait

My past experience on other platforms has led me to the following conclusion: never extend or rewire an O2 sensor.

Good luck man, hope you get it sorted.

Nothing worse than a fire breathing dragon with the hiccups

BlkE55K

Did you have to flash back your ECU to stock so that Kleeman could program the O2 readiness? Jerry told me before this was a Kleeman requirement (stock flash) for them to program the ECU. If this is the case, check also the tune that BIP loaded back on. If you sent in a tuned ECU, maybe Kleeman stock filed it to do their work and if BIP didn't reload your flash file, that may be your issue.

Just throwing this out there since you didn't mention about this in your post. Good luck!

chawkins2001

Yes, it was for o2 sensor readiness, that is why it was flashed. I was told that there is no way the kleeman file could corrupt the bip file as they are on totally seperate parts of the ecu. My base e85 file was loaded back.

Three variables changed, new gas, new sensor with extended wires and kleeman flash for readiness. After that , the drivability has declined badly.

BlkE55K

Has BIP checked the ECU to make sure their file is still good?

BBBSS

I've heard of several cars that are VERY picky with O2's. Extending them has caused issues for some as well, but that may be because they just did a hack job. Universals might be ok on an E350 but on a factory blower motor I'd get direct replacements from a known quality vendor. They can cause all kinds of strange problems. Some LSX motors HATE Bosch O2's but are perfectly fine with an AC Delco piece.

Forrest Gump 9

From the sounds of it, check your O2 sensors. There are four of them so it could get pricey. But sometimes it could be simple stuff like your coil plugs get loose. This happened to me twice in a day, first it was #1 coil. After I got that fix, my #3 coil get loose. There're so much heat on those coil and plugs, the plastic got brittle and the clips broke off on my #1 and #3, same freaking day. Good luck Craig.

WHTEVO

I would confirm that nothing happened with your original tune. Have them check what file is on it. At least this is where i would start. Good luck.

Aaron

chawkins2001

Thanks David, I believe the coil packs were checked and even swapped to see if that changed anything, it did nothing to solve this issue. The only thing that has not been checked, is Komp55's suggested O2 sensor configuration.

Putting my car on the dyno would also spill the beans in my opinion.

novae500

Craig
Not sure in your case, but my friend's clk went through the same thing when he put in some bad gas at a station in a rural area off i95... Had so many misfire codes for all cylinders and felt like cutting out when past 4000rpms. Ended up draining his gas tank and putting a can of BG44K and running it for 20 min on highway with new gas and all codes disappeared.

loungn14

you don't have cats on the car do ya?

chawkins2001

Thanks brotha! I do have any E85 octane tester in the car, I dont think the gas was tested on the second re-fill though. I did not test it when this problem arised a month ago as I was in a rush. I find it hard to believe the E85 at two different gas stations, filled up a month apart, could be the culprit. I will tell you this though, I will never ever fill the car up again without testing the corn.

I dont have cats Jake. I feel like throwing these keys away in the lake, and pushing the car off a damn cliff. I am just sick and tired of battling this car, it just never ends man.

skratch77

with the car runing does it read voltages on the scaner for your 02s? I would put money that there is a weak wire solder or they swapped left and right on ya.

but you said even on boost it went south and that is not running off the 02s at all and using your wot map in the tune so I hope its not coolant in the plugs.

and you probably tripple checked but maybe a plug wire got pluged into the wrong plug.I mean I dont know if it can be done but if you have aftermarket wires that are all the same length I can see it happening.

Jakpro1

I had the multiple misfire happen on my car Chawk. Pulled my hair out until I discovered I swapped 2 wires on the O2 sensor extensions.

Fixed the wires and back in business.

boost420

I have had a few cars that did not take well to extending the o2 wires, had similar symptoms that you are exhibiting. Was a high quality shielded wire used for the extending the o2's as this could be causing interference from the ecu signal?

chawkins2001

It is not the E85 at the pump, gas just measured E90