Ok here goes... trying to get this all into one thread. Hopefully i can get this solved soon!
Since I’ve been trying to get some miles on my car post-swap, it seems to be running quite rich. Monitoring the STFT on the OBDII app, which is still doing what it has been doing - hanging at +27.x% for several minutes, then moves to the opposite -27.x% for several minutes at a time. The O2 sensor voltage readings seem to mimic this movement as well, fluctuating from lean to rich and so on. The car will run fine when cold in open loop, but once closed loop kicks in, the same 4 codes show up. P1188, P1189, P0170 and P0173. It appears that the variances are significant enough that the LTFT refuses to even register. On more than one occasion, the ECU appears to have switched back into open loop due to the repeated faults.
I have smoke tested both the intake and crankcase twice and have not located any leaks. Also checked the brake booster to cover all my bases. As far as I can tell, the engine is sealed up as good as it can be. I’ve read about possible MAF issues, so I pulled the MAF and sprayed it down again with cleaner. I pulled back the rubber boot on the connector and with the car idling, was able to confirm it was getting battery power at the red/white and black wires. I also used my DMM to test the yellow & brown wires. At idle, it would read around .6 and when revved it would jump into the 1.x or sometimes 2.x volt range. Following this, I decided to chance a new MAF on eBay for $50.00. It seemed to cure a slight stumble off idle, but the same 4 codes above came back. The car is a hoot to drive and certainly pulls hard, but the gas mileage seems to be taking a visible hit due to it running rich. I haven’t quite taken it to redline yet since I’m still trying to break in the clutch.
Fuel pressure at idle (with vacuum line connected to the FPR on the rail) is approx. 43 psi. When revving the engine it does not seem to fluctuate much. I have an e39 OBDII fuel rail w/ the FPR built in. FPR itself is new Bosch.
With the vacuum line disconnected from the FPR, the fuel pressure is approximately 52 psi, which sounds in line with other info I’ve read.
With the car shut off and the fuel pressure gauge connected, it reads 46 psi immediately after shut off. I checked about 90 minutes later and it was showing 36 psi still. Injectors were refurbished by MEPEH on the site here. This leads me to believe fuel pressure is not an issue.
CCV system and hoses are all new (m50 manifold conversion). Oil separator is new OEM. With the oil cap off, it does have the slight vacuum as would be expected (will suck in a rubber glove about 1/2” to 3/4”). O2 sensors are new Bosch. Charging system is now in good order and runs a consistent 14V. Tune is thru Markert with the SAP, 3/2 valve and EWS flashed out. I am running the purge valve for the vapor canister. No real mods to the engine except for the m50 manifold and cold air intake.
Timing is really the only thing I haven’t looked at closely - does anyone know what the nominal readings might be?
My data is coming from the DashCommand app from Palmer Performance. I’ve got their ScanXL software on my other laptop and am currently trying to figure out how to view and work with some of the data logs I’ve attempted.
Thanks in advance for the help :drink:
Since I’ve been trying to get some miles on my car post-swap, it seems to be running quite rich. Monitoring the STFT on the OBDII app, which is still doing what it has been doing - hanging at +27.x% for several minutes, then moves to the opposite -27.x% for several minutes at a time. The O2 sensor voltage readings seem to mimic this movement as well, fluctuating from lean to rich and so on. The car will run fine when cold in open loop, but once closed loop kicks in, the same 4 codes show up. P1188, P1189, P0170 and P0173. It appears that the variances are significant enough that the LTFT refuses to even register. On more than one occasion, the ECU appears to have switched back into open loop due to the repeated faults.
I have smoke tested both the intake and crankcase twice and have not located any leaks. Also checked the brake booster to cover all my bases. As far as I can tell, the engine is sealed up as good as it can be. I’ve read about possible MAF issues, so I pulled the MAF and sprayed it down again with cleaner. I pulled back the rubber boot on the connector and with the car idling, was able to confirm it was getting battery power at the red/white and black wires. I also used my DMM to test the yellow & brown wires. At idle, it would read around .6 and when revved it would jump into the 1.x or sometimes 2.x volt range. Following this, I decided to chance a new MAF on eBay for $50.00. It seemed to cure a slight stumble off idle, but the same 4 codes above came back. The car is a hoot to drive and certainly pulls hard, but the gas mileage seems to be taking a visible hit due to it running rich. I haven’t quite taken it to redline yet since I’m still trying to break in the clutch.
Fuel pressure at idle (with vacuum line connected to the FPR on the rail) is approx. 43 psi. When revving the engine it does not seem to fluctuate much. I have an e39 OBDII fuel rail w/ the FPR built in. FPR itself is new Bosch.
With the vacuum line disconnected from the FPR, the fuel pressure is approximately 52 psi, which sounds in line with other info I’ve read.
With the car shut off and the fuel pressure gauge connected, it reads 46 psi immediately after shut off. I checked about 90 minutes later and it was showing 36 psi still. Injectors were refurbished by MEPEH on the site here. This leads me to believe fuel pressure is not an issue.
CCV system and hoses are all new (m50 manifold conversion). Oil separator is new OEM. With the oil cap off, it does have the slight vacuum as would be expected (will suck in a rubber glove about 1/2” to 3/4”). O2 sensors are new Bosch. Charging system is now in good order and runs a consistent 14V. Tune is thru Markert with the SAP, 3/2 valve and EWS flashed out. I am running the purge valve for the vapor canister. No real mods to the engine except for the m50 manifold and cold air intake.
Timing is really the only thing I haven’t looked at closely - does anyone know what the nominal readings might be?
My data is coming from the DashCommand app from Palmer Performance. I’ve got their ScanXL software on my other laptop and am currently trying to figure out how to view and work with some of the data logs I’ve attempted.
Thanks in advance for the help :drink:
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