Can anyone here tell me where number 16 in this diagram runs to: http://www.ricambiamerica.com/parts_catalogs.php?M=FE&P=&V=diag&I=1450 If you have a complete f355 vac line diagram that would be wonderful. Who knows what I'll find next. I had an engine out service performed recently and I'm finding LOTS of little stuff missing or poorly installed. Today I find that vacuum line number 16 in the above diagram is completely missing as was one of the clamps to the diverter valve located at the air pump (and the hose was practically off). I've had code 1126 ever since the service and I'm betting it has to do with this poorly assembled air injection system. Possibly a vacuum leak on bank 2 since the 1126 code is a ltft lean condition and is associated with bank 2. You can't trust anyone to be thorough these days. I knew I should've taken my car to FCI instead of this supposedly reputable European motorsports shop! Uhhg.. anyway, any help is appreciated. Thanks, Nick
No. 16 is the vacuum supply line, it must run back to a solid tube and then on the other side of this solid tube another hose connects to the engine vacuum source.
Darren, item 16 on the diagram is not connected to the solid tube. The hoses which are connected to the solid tube are the ones which control the exhaust valve (item 35 on one side of the tube). Item 16 is in fact a 2 parts rubber tube (items 16, 37 and the union 19) which is connected to the engine vacuum source. It is connected to a T, item 23 on the digram below. http://www.ricambiamerica.com/parts_catalogs.php?M=FE&P=&V=diag&I=1456 Other sides of the T go to 2 non-return valves (item 20), 1 per bank, connected to the throtle bodies.
This board (and you) are a life saver! P1126 is GONE; and the car no longer gurgles like crazy either. What the shop had done was UNBELIEVABLE!! It turns out the line wasn't missing, but NOT connected to the surge tank. Instead they had it connected to the top nipple of the electrical valve which controls the opening of the bypass valve... and NOTHING connected to the bottom nipple of the same electronic valve. So essentially the engine was sucking atmosphere through the bottom nipple of this electronic valve! IN addition, since the bottom nipples on the two electronic valves are t'd from the same source, neither of them were operating (no bypass valve function nor diverter valve function because of no vacuum source). The car runs SO much better! Now if I could just eliminate codes 1445, 1449 and 1448 (all 3 cat ecu codes). I've replaced all cat ecu's with no results. I've capped off all thermocouple inlets and left the thermocouples to measure ambient air temps. I've gone to straight pipes. Nothing resolves the issue. My slow down light just blinks but doesn't worry me because there's nothing to overheat in the exhaust anymore --nick
If the central thermocouple does not get hot when the exhaust bypass valve is supposed to be open it will cause a CEL. Hanging out in the wind does not insure it isn't causing a problem.
That blows because my exhaust has no place for the bypass valve TC. So I guess the cat TC's would throw a cell, too? The problem is that 1445, 1449, and 1448 cat ecu errors existed when my exhaust was stock. Before upgrading the exhaust all three cat ecu's were replaced for the green types... No fix. I'm thinking there's an issue someplace common to all three units. I don't know if that means a bad motronic of what. Daniel @ Ricambi is sending me a service manual PDF. Hopefully I can trace the wiring to something common to the units and start there. Nick
Hope you've marked or color - coded all these bits so they can easily go back together (to the right locations!) during future work.
The thing is... I'll actually remember this. After studying the vacuum line layout, it's actually quite simple and intuitive once you understand how the vacuum actuated devices operate. The reason that at first glance I didn't know where the missing connection should run is because the shop had the source connected; but in the wrong place. Had there been simply a 'dangling' line it would've been more obvious. I'll just make sure that any future work is not performed by the place that did this I'm noticed tonight that the fuel vapor filter isn't clamped in as it should be. Items 6 and 7 are missing in the following diagram: http://www.ricambiamerica.com/parts_catalogs.php?M=FE&P=&V=diag&I=1453 I'll never go back there again. If I had the time I'd actually do this work myself. At least everything would be connected properly with no missing pieces... even tidy'd up a bit based on the condition when purchased a couple of years ago. This just makes it even harder for someone like me to delegate anything and trust that it's done properly. --nick
Just replug the cat thermocouples, even if you have straight pipes, and measure the voltages on the 3 wires connectors while connected to the cat ECU. You should see +12V (when ignition is on), ground and a voltage which is temperature dependent (probably around 0.5V at idle). That is the minimum to be checked ... For the third thermocouple, because you have no place to install it, you can probably avoid the DTC by simulating a voltage change on the relevant Motronic input according to the exhauxt valve command. Not that difficult to simulate let's say 1V when the valve is closed and 3V when it is open .... Never tried that though, we don't have this stuff on euro cars, but it may work ...
Some new (GOOD) news for me. After I reconnected the vacuum lines properly, I didn't clear the codes for the ECU before driving. After fixing the vacuum leak and driving, I checked the codes to find that it had resolved p1126, but that I still had codes 1148, 1149, and 1145. It just so happens that I cleared the codes again and have since driven the car all week. I check the codes today and I only have 1445 and 1449; NO 1448!! It seems that when I fixed the vacuum line and immediately drove, 1448 must have already been pending in the ECU; eventually throwing a CEL. Clearing the codes SINCE the vac line fix has eliminated 1448 I think because the bypass valve solenoid is actuating now (it wasn't receiving vacuum to work when the vac line was disconnected). The fact that the bypass valve solenoid wasn't opening and closing properly was throwing the 1448 code; not the fact that the TC for the bypass valve isn't inserted into the exhaust (because I have no place for it). I guess the bypass valve only throws errors when the solenoid doesn't actuate, or when it's stuck open and the TC see's heat when it shouldn't on stock exhaust (these are the only times I've gotten 1448). Now I'm going to reinsert the TC's for the catalytic converters (straight pipes for me) to see what I get. At worst, still just the 1449 and 1445; meaning I'll have some more troubleshooting to do. Since all of the cat ECU's are new, and the TC for the bypass valve is also new (and it now has no errors), the issue of 1445 and 1449 COULD be as simple as two bad thermocouples (occam's razor). They're not that expensive. I'll order two and see what I get. But as it stands... 1126 is definitely gone, and 1448 seems to be gone since it hasn't shown up after a full week of driving. I'll keep posting my findings. Thanks, Nick
I think that may fix it. When I welded up some high flow cats for my car I left out the TC's initally thinking it wouldn't cause a problem. I got codes 1445/1448/1449, flashing slow down light, and check engine light. I've since re-installed the catalytic TC's and now everything is perfect. No codes, no lights. (also, bypass TC is still tied off and not installed).
Hallelujah!!! A year trying to resolve 1448, 1445, and 1449; replacing all cat ecu's and more, the issue is resolved ! Don't let anyone tell you that the thermocouples are usually 'frayed' when they're bad. Turns out they can foul out just like o2 sensors, maybe just not as soon. I replaced the thermocouples (very discolored... a very dark brown color) for all three cat ecus... no more blinking slow down light and no more CEL (even though my TC for the bypass valve is reading ambient air temps because of no place in my new exhaust for the connection). Another case of the simplest solution being the correct one (occam's razor). Now I don't have to resort to pulling the bulbs --Nick
Great job, Nick. Glad to hear you solved the problem. Chasing down trouble codes can bring one very close to the brink of insanity.
Tell me about it! It's a mental thing for sure, having error lights on the dash. I wasn't feeling very good about owning the car for a while. Now I love it again. Almost considered selling her and try driving the 612 more often. May sound silly, but the f355 is my favorite (again)! --nick
Thermocouples cannot "foul out" like o2 sensors because the exhaust gas does not reach the sensing "material." Unlike o2 sensors, the thermocouple's tube body and tip do not have any openings for the exhaust gas to enter. Basically the thermocouple tip is two wires twisted together. With time, vibration may have some effect on the point where they twist together or maybe some additional resistance may build up on the conductors (corrosion, oxidation etc.). Of course there could be a problem away from the tip with the wiring too (either inside or outside of the tube body.) Even getting heated to a point near their upper temperature limit or beyond can affect their performance or shorten their life if it's repeated or for more than a short time. So yes, they can go bad/get old but for different reasons.
So excessive carbon buildup, etc. on the Thermocouple probe can't cause an issue? Possibly causing delay in temp readings? I say "delay" because when the tc's were not inserted into the exhaust, I received slowdown warnings and CELs almost immediately after driving. With the fouled (excessively dirty) thermocouples in place, the slow down light would flash when the car was stopped, as if the slower moving exhaust wasn't enough to be read by the "blanketed" tc's. When driving, the slow down light would stop flashing, as if now the exhaust was moving fast enough for the tc's to now register through the "blanket of build up". --nick
I certainly don't think it would be a factor. When your car is stopped (but running) your exhaust temperatures are going to be lower (if idle mixture is correct). Thermocouples are not "interested" in the speed of the exhaust but simply the temperature. You mention slowdown warnings and CELS's with the thermocouples not in the exhaust stream. You should never get a slowdown warning with the thermocouple removed from its "holder." It simply would not get hot enough. That's not to say you will not get a false indication. I get what I would call random slowdown lights using test pipes. With the cats. removed you should never see a slowdown light (if the thermocouples and their ECU's are good).
Right, but it certainly seemed as if the faster exhaust was necessary for the "heat" to permeate the probe. I don't know. What I do know is that with the original tc's, I had a blinking slow down light with reduced speeds (tc's inserted). With the original tc's removed from the exhaust stream, I received a blinking slow down light immediately. Purchasing new tc's and leaving them out of the exhaust stream caused immediate blinking of the slow down light. Deciding to insert the new tc's into the exhaust stream (because at this point I thought there was some other issue and would rather have the slow down light only come on when I actually slowed down) resulted in no blinking slow down light and no 1445 and 1449 codes. I'm running test pipes as well and so far have had no more issues. We'll see how long it lasts --nick
Faster exhaust flow would typically indicate higher rpm. Higher rpm would typically result in higher exhaust temperature. Anyway, I think I'll be removing my "slowdown" light bulb. Don't want to see it flash when there are no cats. installed. If I had my cats. installed all the time (or any significant amount of time) I would certainly sort out the ECU and/or thermocouple problems rather than removing the bulb.
I hear ya. I almost went there but was determined to resolve the issue even though I have test pipes (this problem arose before I'd removed my cats). Part of tracking down this problem is what led me to straight pipes in the first place; removing my hyperflows. When that didn't resolve anything, I replaced all 3 cat ecu's. Silly me, not adhering to a rule that I ALWAYS abide by in my line of work... to start with the simplest of solutions. Not only are they usually the right solution, but also the cheapest! Can't believe I didn't try replacing the thermocouples first! Oh well, at least I know that entire system is new now
Well... the cat. ECU's are "known" to be the "usual suspects" so that's not the worst place to start looking/swapping. Having said that, I also understand your interest in these components/circuits not getting the better of you. Some of the problems on these cars are just plain annoying. At the end of the day I would rather have no cats. at all on the 355 as they seem to be fully capable of catching fire without the help of an overheated catastrophic converter
That's scary. Hopefully the ones that catch fire are usually result of fuel leaks. I had my entire exhaust system coated in SwainTech's white lightening. That coating is amazing! Engine bay temps measure considerably cooler. And within just 15 minutes of shutting the car off from even a spirited, 30 minute drive from work; I can literally grab any portion of the exhaust by hand and it's only mildly warm to the touch! Great stuff!
So did I (well, the headers and test pipes anyway). Don't know if you saw this thread or not: http://www.ferrarichat.com/forum/showthread.php?t=279960 Image Unavailable, Please Login
Awesome. I see you have the Capristo bypass valve. So do I I had my fabspeed headers, fabspeed y-pipe, larini straight pipes, and larini silencer coated. The exhaust tips are not coated. I viewed that thread; your temps measured pretty low! Before the coating, I measured in the low 800's. After the coating I measure in the mid to high 600's. I measure after driving, though. --nick
