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Did the first drive this morning, 50 miles. The car felt great, pulls hard, idles perfectly, no CEL. I plugged in the Durametric after I got back and have some borderline readings. I’ll list them below
should I be concerned or do I need to finish the break In period before worrying about them.
Engine Roughness- all cylinders are bouncing around between 0 and .6 except cylinders 2 and 4. 2 is 1.5-2.3 and 4 is -1 to -1.6
Fuel trims- FRA bank 1- 1.13
FRA bank 2- 1.13
RKAT bank 1- 1.59
RKAT bank 2- 1.69
Cam deviation- bank 1- -2.83
Bank 2- 1.63
did I do a **** poor job on the timing? I checked it so many times….
I hadn’t done a smoke test after getting the engine installed, I did one before installing with the brake booster plugged.
figured I’d do another one just to see. I had the slightest of leaks on the elbow. I’ll replace the elbow with a short piece of hose for now and see if that makes a difference in the fuel trims.
Your cam deviations look fine. Are your fuel trim readings from durametric (values vs. percentages I assume)? If prior, those don't look good. I assume the dash prior to the number is you seperating the number from the text vs. noting positive or negative value? If prior, list if it's a positive or negative value.
If the fuel trim readings are actual values and not percentages, you should be showing fault codes soon. Sounds like you are already going down the path to improve those. I haven't followed your build but LN's recommendation is not more than a 5% deviation on fuel trim for break in.
Vacuum leak, fuel injector leaks, exhaust leak, secondary air injection malfunctions, bad o2 sensors, bad knock sensors, and I am forgetting a few.
thanks for the list. I’m guessing that since I have high numbers on both banks it’s most likely an issue that’s common to both banks, like the vacuum leak, weak fuel pump, secondary air injection.
I pulled the battery overnight to reset everything to factory specs again. I’ll fix the small vacuum leak and give it another short 10 mile drive to warm up and check it again. Hopefully I’m not going to harm anything by doing so.
Moving in the right direction but still not in spec.
FRA bank 1. 1.14 No change
FRA bank 2. 1.13 no change
RKAT bank 1 .66
RKAT bank 2 .66
i did make a discovery, o2 resistance pre cat bank 1 64 while o2 resistance pre cat bank 2 is 0. I can’t seem to find any info on what they should be but I’m guessing 0 isn’t correct.
I did increase in size. From 3.4 to 3.8… if I’m understanding the statement behind the question increased displacement would require more fuel to keep the mixture where it’s supposed to be. Is that correct??
Yes, correct. However, the MAF will measure the greater amount of air being sucked into the bored-out engine and the DME will inject fuel accordingly. From what I've read on here, the DME can compensate and doesn't require re-calibration of fuel and/or timing maps.
Compensation for increased displacement cannot be done via long term fuel adjustment as that is limited to 3% before a CEL is shown and 3.4->3.8 requires 10% more fuel (on average).
As such and in your case any compensation by the DME points towards either too much air or too much fuel and requires identifying and removing the cause.
Yes, correct. However, the MAF will measure the greater amount of air being sucked into the bored-out engine and the DME will inject fuel accordingly. From what I've read on here, the DME can compensate and doesn't require re-calibration of fuel and/or timing maps.
Compensation for increased displacement cannot be done via long term fuel adjustment as that is limited to 3% before a CEL is shown and 3.4->3.8 requires 10% more fuel (on average).
As such and in your case any compensation by the DME points towards either too much air or too much fuel and requires identifying and removing the cause.
Thanks for the information. I guess that my hypothesis on the other thread is wrong.
I removed the o2 sensor that had a resistance of 0 and put the original back in. It did make a significant change.
I did realize that the FRA numbers are a % and not value. Still not sure if what I’m reading is good or not. Also, both FRAs went to 1.02 when under load.
I checked fuel pressure and fuel flow today. Both were good. Checked for exhaust leaks with a little soapy water (before it warmed up) no issues.
the last piece of the puzzle are the injectors. New ones will be here soon. Probably install next week.
02-18-2023, 12:39 PM
Parameters after rebuild
