The rpm sensors are the Kia and the phase sensor was oem from ricambi. Those 3 parts did clear their associated codes. And cool on the pins... what could go wrong? Sent from my SM-G930P using Tapatalk
You mean the thermocouple ECUs? pulled them and also swapped side to side. CEL didnt follow. Sent from my SM-G930P using Tapatalk
Put a 1K ohm resistor between the pins 2 and 3 and see what voltage reading you get at pin 3. You want it to be much lower than 2.5V, somewhere between zero to 500mV
Which shematic are you looking at? maybe I'm missing it in one of the manuals. Here's photo of the male side of the connector to check resistance.. which pin is which? Image Unavailable, Please Login
Tried resetting all connections. Haven't tested resistance yet. Same issue. Idles around 1k..then stumbles to 800, lights the CEL 1-4 then comes back to 1k. Coded 4121. Could it be a bad RPM sensor and feeding back false 4121? Sent from my SM-G930P using Tapatalk
Afternoon Update: Here's what I've done this afternoon: Disconnected the battery again as I fiddled with stuff. At the advice of another fchatter who said he had a similar ghost issue with that code he suggested swapping the MAF's and see if it followed. So I pulled them and figured while I had them out give a good shot of MAF cleaner. Seemed a bit dirty but I'm looking for anything. I went back through what amounted to all the connections again on the 1-4 bank and disconnected and reconnected. I did find one I missed however in my first go round (pictured below). Flipped the battery on again, Cleared the codes and fired her up. Started right up, went through warm up cycle. Then ran through a couple of fan on's and knock on wood... so far no codes. Even a couple of times the idle dropped a bit from 1k but no codes. Before this she'd throw that 4121 just sitting there and then keep throwing it. Unfortunately I don't have time to secure the Main ECU's and take her out for a spin to see if she's truly fixed or not unless I bolt from the in-laws early today. Not sure the wife will go for that -- heading back to take care of the mistress.. LOL So I'm still perplexed and not totally sure it's fixed or not. Any other thoughts? rants? suggestions. I do still need to test the Ohm too as I doubt it's fixed. But trying to find that schematic to do it. Thanks for all the suggestions and help so far... MUCH APPRECIATED! Image Unavailable, Please Login
As soon as i can find 99% isopropanol I'll mix it with my stabilant and coat the connections. Sent from my SM-G930P using Tapatalk
I had a couple of misfire codes and it turned out to be a bad wire going to one of the injectors. I found it by jiggling wires around when it was running. I ordered some new connectors and replaced a few of them. Hope you found the issue.
Yep these cars are 20 + years..mine is 23 now. Stuff is gonna fail and not logically. Sent from my SM-G930P using Tapatalk
Im just gonna copy and paste from the other thread: You may need a frash set of EPROMs, and maybe even repin the T55 connctors??? Years back I had a bunch of weird CEL codes, swapped out all brand new sensors, issues persisted. Installed a fresh set of chip *presto* the madness stopped. Here are my diy threads for both. http://www.ferrarichat.com/forum/technical-q-sponsored-algar-ferrari/351819-348-ecu-removal-chip-removal.html http://www.ferrarichat.com/forum/technical-q-sponsored-algar-ferrari/444155-348-motronic-2-7-connector-harness-repin.html But before you do any of that, have you tried swapping the Motronic ECUs from side to side to see if the problem follows?
I did swap the the ECU'S. Code did not follow. Is the guy still making chips? Id love to replace them. Sent from my SM-G930P using Tapatalk
Have a new set of chips coming as still not sure of issue. Took her out tonight. No codes but ran like crap...hesitated from aboy 1500 to 3k... and it sounded almost like not all the cylinders were firing..weird exhaust burble. No CELs. Wasnt far from home so got her home. On a whim swapped the main ECU'S back to original spots. Bam! 4121 on 1-4...and rough running. Turning off the battery and gonna let her sit overnight. Anybody have any ideas? Really trying to avoid taking to shop. Sent from my SM-G930P using Tapatalk
I would replace the EPROMs and see what that does. Then double check: Grounds on the valve covers Ground to the subframe Spark plug wires Spark plugs Motronic ECUs are screwed down properly Coil packs Ignition control modules Maf Throttle position sensor If that doesn't do it then I suspect the wiring harness. Check to make sure the harness is not grounding out on the hole through the fire wall. Make sure rubber grommets are pulled through properly and seated to protect the harness. If it is cutting through the harness then you are gonna have to repair/replace the damaged wire. If not then a repin maybe needed. The T55 connectors should get repinned away if it has the old, double ear, Junior Timer pins. I used tin played Junior POWER Timer (Cost aprox $140+/- total). I also cleaned off the tin oxide on the male pins in the Motronic harness receptacle. Hope that helps.
Got my new eproms. Looks like my ECU's have been opened before. Gotta review the procedure ernie wrote up. Sent from my SM-G930P using Tapatalk
Even though I've been fighting a very similar problem I've resisted posting in this thread because I did not want to spread misinformation-- there's too much of that here to begin with. But I'm now to the point where I can say that it seems that my recent exhaust ECU CELs/codes were caused by bad connections. After letting DeOxit cleaner work on all of the associated connectors we ran the car recently for a couple of hours at way beyond triple digit speeds with no more CELs, and that's before I've even applied DeOxit Gold to the connectors. So I think you're onto something by suspecting connector problems, although I would suggest using DeOxit instead of Stabilant (I own both and have zero affiliation with either). Good luck.
Mike, Thanks I'm really trying to avoid a repin. I do have stabilant but haven't used it yet. Today i unplugged the o2, tecu and the damn thing still thru a 4121. Complete BS. What connectors did you do? Sent from my SM-G930P using Tapatalk
I started out with just the connectors to the exhaust ECUs but that seemed to be working so I wound up doing every connector in the engine bay. It took a while to get the desired results though-- I applied DeOxit D100 to the exhaust ECU connectors and just let them sit open for several days, reapplying at least once. Got the urge to drive the car so I just remade the connectors without further cleaning and a couple of test drives seemed to indicate that I was on the right track, although the 1-4 CEL eventually reappeared due to 4121. So I disconnected pretty everything I could reach in the engine compartment and applied more D100. The last test couple of drives totaled well over 100 miles, a good portion of it well over 100 mph, but no more CELs and the car seemed to run better as well. I still need to clean out the D100 and apply DeOxit Gold, which I've found to be very useful in enhancing/protecting contacts. But at this point I have a good deal of hope that the combination of cleaning with D100 and eventually protecting with Gold will resolve one or more problems, including the 4121 CEL. Note that Stabilant does not clean contacts, at least as far as I know. It is also said to leave behind deposits once the connection is broken. AFAIK, DeOxit can be fully removed by using solvents and the D100 has proven to be a good cleaner when I was playing with vintage audio gear. So even though I bought and even mixed up some Stabilant, I've decided to not use it on the 348 out of concern that it might eventually cause its own issues. Besides, seems to me that 25 year old contacts need cleaning before they are protected anyway. Just my two cents worth-- there are others on this forum who are trained on the subject who know more than I do, but I've not seen any warnings against the use of DeOxit. HTH and good luck!
Got my Deoxit and started on all the connectors in the engine bay. Also hit the connectors to the ECU's. None of the pins look at bad as Ernie's in his writeups... but I would bet back into the insulation they are corroded. Not sure the D100 is going to go back that far but we'll see. Eprom replacement either tonight or tomorrow.. need to get my wrist strap.. have the mat but they didn't ship the wrist piece. I am not looking to fry any ECU's. Fingers crossed... I'll get to drive her this weekend with no issues. Bought two direct fit O2 sensors too... I used the universal ones before.
My setup - in stooge in honour of Ernie's efforts. Well will you look what I have in here. No mention in my records of this little puppy. This was the original ECU from the passenger side. What is that .. like the big mac of EPROMS? and look there's no cover like in the guy's examples. Wonder what I'm going to lose if this thing works? hopefully some .. CEL's... LOL Ideas? Anyone seen this chip previously? know anything about it? btw -- thanks to Ernie and 3forty8's write ups... had the case opened in less than 10 minutes. total job for both was 30 minutes. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Afternoon Update: Swapped out the superchips for the OEM burn Eric set me. Reinstalled the ECU's DeOxit'd everything (2 times). Noticed lots of "blue" in some of the connectors... especially the ones near the ECU's (white connectors) Put on the DeOxit connector enhancer on all connectors Turned power back on to the car. Started her up. let her run through the 15 minutes or so of warm up. Slowly took her out. Runs extremely rough. No CEL's but definitely isn't running right. Now I'm kinda stuck as to the next step in the troubleshooting process. I did check all the grounds and they are fine as well. I remember one time I had another car and the "technicians" hooked up an air hose to the wrong spot -- basically crossed them. I haven't had any of the hoses disconnected. But maybe something with that? Any suggestions as to what to try next? I'm almost to the point of taking her to an independent if I can't resolve soon. Help!!
First thing I'd do would be to reinstall the previous chips and test drive. Also, make 100% sure you reconnected everything you had loose when applying DeOxit. Like I said before, the D100 can take a long time to work. I've had mine on for a few weeks now and it seems to have finally done the trick. I've driven the car several times with no CELs and even the almost imperceptible hunting at steady speeds (which I'd previously attributed to weak O2 sensors) seems to have disappeared. And I haven't even applied the DeOxit Gold yet, which has worked wonders in other places. I'm very pleased with the results so far but it really does illustrate just how bad the terminals are in these cars. Mine look brand new but they obviously weren't doing their jobs correctly. No wonder the people who have ponied up for the SR gold kits are such big fans. Don't give up yet. These problems take time to resolve and the stuff you're doing is the same stuff a pro is going to be doing anyway. Find the cause of the rough running and keep applying DeOxit (and give it plenty of time to work).
Well the new chips took care of the CEL. But the rough running is still there. I haven't pulled the plugs yet so i thought I'd do that and see how they look. Need to go get the right size socket for them though...I think its an 18mm and I don't have a sparkplug 18mm. I guess I was hoping the rough running would be something obvious to test...like another sensor or something...like a pro would go "oh yah its this". So for now i have a heavy piece of garage art...lol
David - I guess I'm going to be the sticky wicket here... the lack of CEL lamps being illuminated, alongside really rough running, makes me wonder if these chips are simply going to obfuscate the diagnostic process. Is it possible that whatever coding magic is inside those chips, they've simply disabled the lamps and now it'll be more difficult to identify the exact problem?
