Lifter project is complete, but I'm getting a rash of ECM codes

[mnichols]

I'm looking for a bit of troubleshooting advice. I've just completed some major work on my 1995 M3. New hydraulic lifters and all new intake manifold gaskets. To say the least, the engine has been in pieces over the last month. I finished the work yesterday and started the engine for the first time. To explain something, the engine has 24lbs injectors, so when the ECM power is removed and memory is lost, it takes 10 minutes of street driving to get the ECM to adjust the fuel air ratio to allow the engine to run smoothly, when you first start it in these situations it run very rich.

So. . . when I first started the engine and it ran rough, that seemed normal since I had the battery disconnected for all of the project.

However, after a short drive the rough idle did not go away. It seem to run at speed ok, it has good power and runs smooth, but runs rough at idle.

The ECM did not light up the Check engine light after it was first started as it usually does. The light stays on for a few minutes as the ECM adjusts the fuel air ratio. For some reason this time the light never came on?

Finally after a 20 minute drive the Check Engine light did come on and stayed on.

The code reader has numerous error codes, one is strange.

0F which is an ignition secondary monitor code for an M8 V12?
01 electrical fuel pump relay
33 ignition coil #3
19 ignition coil #5
0D oxygen sensor

The ECM seems to have power, the code reader can access its memory, its setting faults.

The car runs good at speed, so the fuel pump relay and fuel pump must be working

The ignition coil errors and oxygen sensor errors seem random

All of this might come from the same issue, and that's what I'm looking for. Any ideas what to check or where to look?

[Casmige]

What a Project!!,

Adjustable Fuel Pressure Regulator??.

When I did the Big-6 AFM Update along with 19# Injectors on my e30, the Write stated to slowly adjust the BAR "Up" on an Adjustable Fuel Pressure Regulator so the ECU/DME Could "Learn" & adjust the Fuel Mapping Injector Pulse Curve (Way over my Head, sorry).

Reading your Post I thought of this.

Also, from experience the O2 Sensor Code is ALWAYS "There" if you have any sort of Mis-fire.

On my e46 I swapped over to Brand-New Late Model V-8 Coils after accidentally updating to a later model Valve-Cover (That's a nice Long TMI Story!!).

Point 1 is that I had to re-arrange the Wires at the Plug Connector from what it "Was" to what it was supposed to be....the Physical "Plug" was the same...the wires that junctioned through it were arranged differently compared to my old Coil Wiring harness feed.

Got it all back to-gether & found a "Miss" also on one Cyl.

As easy as the Push & Clip connectors are & as idiot proof as the job of connecting them should be, I found that I had missed snugly connecting & snapping down one of the connectors on the coils.

THAT Caused my "Cyl. Miss" + the Subsequent O2 Code on my Project.

I'd double check the Wiring for the Plug-in at the ECU/DME Junction Box AND the Snappers on the Coils themselves to be 100% sure.

Hope that helps a bit??.

[mnichols]

Casmige,

Thanks for the ideas. I went back and reconnected all of the coil wires just to be sure and pulled the connector on the ECU and check voltages per the wiring diagrams, all ok.

Restarted with the same issue. It seems each time I clear the codes and restart the engine, there are different codes. This time I got a 1A which is a control supply error. Hence my checking the voltages at the ECU connector.

I also checked the output of the voltage regulator to insure that the ECU wasn't getting 15 or 16V? But it was right on at 14.3.

Still thinking about what changed and how it could have caused this issue??????

[mnichols]

I thought I would post the cause of my rash of error codes and rough idle. The time worn rule of troubleshooting is to return to the things you have touched as suspects.

The engine runs so quite now that I can hear other noises. I thought I could hear a vacuum leak, so I used a mechanic friend's smoke system. The smoke bellowed out of the Air Hose Connector O-Ring which mates it to the Intake Manifold. This hose and connector are extremely hard to see, they are under the middle of the intake manifold. During the lifter upgrade, I had removed the intake manifold to replace all of the intake gaskets, I must have bumped that connector and cracked the housing. New connector and the engine runs perfect.

If you have noisy lifters in your older cars, the lifter upgrade is worth the effort. Back to the track in 2012!