Hey bretheren. Went for a cruise with some Ferrari buddies and had to cut it short becuase of a CEL 5/8. Car went to intermittant Limp mode but I got her home. Pulled the codes and got a 4121 (Cat code). Hmmm, no slow down light before CEL. Figured I'd swap sides for ECU test. Cleared all codes. Now I got a 1111 5/8 (Hot Wire MAF). Performed a master ECU reboot, cleared all codes again, now everything is fine...no more CEL. Took her for a quick and hard spin...still fine. Today went for a 100 mile melow ride, no CEL. I figure everything is OK and the indication was a loose connection, bad gulp of fuel, or something. Am I missing anything? Do I have something getting ready to bite me?
Can't hurt to buy a $7 can of MAF cleaner and spray down both sides of each MAF for preventive maint...
Good point... perhaps a differant issue, perhaps related. I've recently experienced a major electrical issue that manifested with a bad battery cell and a direct short in the alternator. The issue caused numerous surges in the wiring harness. Since that has been repaired, I've notice a change in intake noise upon cold start. It used to sound very throaty till warm then settle out. I assume a bypass valve. That throaty sound no longer exists. Could this be the master problem or just indicative of warm summer months? FYI Mafs at 385 and 386 Ohms
I have no clue about the startup sound/electrical surge! Me...I'd ignore it if I didn't see other symptoms. *whoops, did I type that in public?!
Lane, your intake sound seems to be the cold exhaust air injection system. Normally when cold (below 130 deg F coolant temp IIRC), ECU will turn on solenoids to inject cold air into the exhaust headers to lower emissions. The injector air pipes include on/off and check valves, and I've heard some owners say they like the sound this system makes while the car is warming up. On my car, these valves just rattled on both sides and sounded like a box of rocks. So I just removed the system during the major I did. Less clutter, fewer vacuum hose connections, and less weight! At any rate, seems that perhaps your solenoids are now not opening to activate this system. Perhaps connections. Best of luck with the car!
Rick...I like the sound also. Where are these solenoids located? Are they Relay'd or fused? Happen to know which relay/fuse? This stuff? Image Unavailable, Please Login
The solenoids are to the left and right of the oil filter, on brackets that are bolted to the intake manifolds. See my pic (hope it's not too hard to see). You can see a connector from the wire loom connected to one of them. My understanding is that wiring comes from the ECU directly to turn on the solenoid, so I don't think there's a fuse, and no relay at all. I think I heard that just ONE of the ECUs turn on both left and right solenoids, but I could be wrong. It could be wiring, solenoids, or it could even be a vacuum leak, since the solenoids just pass the vacuum to the on/off valves by the exhaust to turn the system on and off. Lots of vacuum hoses connections there, and a plastic black vacuum accumulator bolted to the frame that could also leak. I suppose I'd remove the solenoid connector wire, and just check to see if you get a signal on the connector from the ECU when the car is started cold. PS - I just left the solenoids on my car, even though I removed most everything. I did this because the solenoid mounting brackets are bolted on with intake manifold bolts, and I didn't want to risk causing a vacuum leak on the manifold! Edit: I attached a copy of Ricambi's diagram before seeing you already had it picked out! 16 are the solenoids. Hope you can find the problem http://www.ricambiamerica.com/parts_catalogs.php?M=FE&P=&V=diag&I=3062 Image Unavailable, Please Login Image Unavailable, Please Login
BINGO... Just went and checked the air system as described by Rick. Found a vaccum line had seperated from the actuator canister (part 8) on the 5/8 bank. Refit the vaccum line and presto...Throaty sound is back. It may also be the ultimate cause of my CEL as it was indeed a vaccum leak. Thanks Sir...
I think I was looking while you were typing. What a team. I thought I had noticed an increased Unburnt fuel smell but I was near a few other cars. I was blaming it on a TR to one side and a 308 on the other. This information suggests it was probably me. Good thing I didn't say anything.