| Author |
Message |
Phil Hughes (Ferrarifixer)
Member
Username: Ferrarifixer
Post Number: 258
Registered: 7-2003
| | Posted on Wednesday, October 29, 2003 - 3:23 am: | |
You can get the weatherproof connectors from wurth or elsewhere quite cheaply.
Just make up a bridge wire about 50mm long to connect the two pins on the t/c ECU. |
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 60
Registered: 2-2003
| | Posted on Tuesday, October 28, 2003 - 6:46 am: | |
Phil,
How do you bridge it? (how do i make one?) |
Phil Hughes (Ferrarifixer)
Member
Username: Ferrarifixer
Post Number: 251
Registered: 7-2003
| | Posted on Tuesday, October 28, 2003 - 2:58 am: | |
We race the 360 challenge cars with the t/couples ECU connection bridged and t/couple in a box under the bench.
Michelotto N-GT cars have wiring loom modified to do exactly this, despite their claims that they re-write the ECU map to eliminate it!
Being bridged simply fools the ECU to think it's all at room temp.
There is usually 3 stages of warning. Need to see manual to confirm exact temps but....
1 at hot=Light flash
2 at very hot=light on
3 at too hot=bank shut fuel down |
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 58
Registered: 2-2003
| | Posted on Monday, October 27, 2003 - 11:40 am: | |
well, i disconnected the exhaust ECU on the 5/8 side, have been driving the car regularly, and have had no further issues. |
billy bob (Fatbillybob)
Member
Username: Fatbillybob
Post Number: 412
Registered: 8-2002
| | Posted on Saturday, October 25, 2003 - 6:10 pm: | |
Here is a funny ghost! The 348 will run fine with the ecu's disconnected and should never trigger a mil light. Only the check engine will light from other issues. Well I have seen such bad 348 wiring that the slowdown lights can come on when there is not input to make them come on! I bet more that one person has seen this but I bet no one has an answer to why this can happen. Just another 348 data point. |
Stanley DiGuiseppi (Standig)
Junior Member
Username: Standig
Post Number: 105
Registered: 5-2002
| | Posted on Saturday, October 25, 2003 - 4:09 pm: | |
James
I have 90 348ts. Had erractic problem with slow down lights. I put test pipes on and strapped the thermo's to the side of the frame. No more slow down lights.
If you are losing a bank check codes first. There is a new post that shows codes for 2.7 motronic. I just copied them for myself.
If you are losing fuel perhaps from fuel pump shutting down it would make car run lean and over heat the exhaust which would put on lights.
If it feels like the whole bank is dead than you have something common to that half of the engine. ECU ? Fuel Pump ? Fuel Pump Relay? Fuse connections.
I had a 87 TR that would lose power. I diconnected one ecu at a time to determine which bank. Then I was down to either fuel or electrical fault. I found no fuel. It ended up being a over heated wire just before the fuse in the front engine compartment. Fortunatly I was able to make it act up in the garge.
Moral of the story? Start with basics.
Assuming the engine is sound. Start with codes. Then check fuel delivery.
Plesase keep us posted on the progress or the outcome.
|
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 55
Registered: 2-2003
| | Posted on Tuesday, October 21, 2003 - 10:37 am: | |
Rob,
i am new to the 348. my 308 did not complicate my life like this. LOL. it DID have it's own set of issues, but not like this.
back to my point, sorry,... i have no idea how to get the error codes in the first place, or how to interpret them once obtained.
the service history is spotty at best.
i will check the potting like you suggest, and am going to swap ECUs this weekend. but, you implied that other conditions can cause the same effect.
can you answer what they are?
|
Rob Schermerhorn (Rexrcr)
Member
Username: Rexrcr
Post Number: 846
Registered: 11-2002
| | Posted on Tuesday, October 21, 2003 - 9:21 am: | |
James,
A malfunctioning thermocouple ECU may/will cause the issues you describe, but so will other causes. What are the error codes?
What is the service history? There is an improved thermo ECU available. The quick test for what generation thermo ECU you have is to press your fingernail into the potting material, if it's hard, older generation, if it yields to your fingernail, you have the latest design. The older thermo ECU's don't age well, the newer generation takes the heat of the engine compartment better.
As Steve stated, they have no other function than a transducer of temperature into electrical information the engine ECU can understand.
If it's only one bank, you can try swapping thermo ECU's side to side to see if the error moves. Always try the cheap and easy first.
Rob |
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 54
Registered: 2-2003
| | Posted on Tuesday, October 21, 2003 - 9:16 am: | |
that is my assigned task for this weekend.
i'll let you know. my guess is that it has to be. nothing else makes sense. my plan is to leave themocouples in place and just swap ECUs. |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 2168
Registered: 1-2001
| | Posted on Tuesday, October 21, 2003 - 9:05 am: | |
I believe if the slowdown warning light comes "on" anytime on a test pipe-equipped F during rational use (and it's got it's normal behavior/power) you can be fairly sure the warning light ECU is flaky (or getting flaky). To get to the next level of (surer) diagnosis, I think you would need your 348's wiring diagram to verify that the warning light ECU has two separate outputs (one to run the warning light and another output to communicate with the injection system -- otherwise, I don't see how your #2 could ever occur) and measuring what's going on on that line going to the injection system.
Have you tried swapping the 1/4 warning light ECU and the 5/8 ECU (if so equipped)? |
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 53
Registered: 2-2003
| | Posted on Tuesday, October 21, 2003 - 7:00 am: | |
Steve,
Yes, actually i have both conditions...
1) the 5/8 bank shuts down with no light on... (sporadic, last night it did it in conjunction with the light - which blinked 3 times, went out completly, followed by loss of power to bank.
2) the 5/8 light comes on (steady) with no shutdown...(this is the most common. i think it is a ghost. seems to be better after i cleaned the connector, but still does it).
your thoughts? |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 2167
Registered: 1-2001
| | Posted on Monday, October 20, 2003 - 3:57 pm: | |
Are you saying:
1. the 5/8 warning light comes "on" and the 5/8 bank shuts down,
or
2. the 5/8 bank shuts down, but no 5/8 warning light? |
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 52
Registered: 2-2003
| | Posted on Monday, October 20, 2003 - 3:46 pm: | |
seems i am still stuck with the same problem as when i started - how to make it stop shutting down the 5/8 bank for no reason.....LOL!
guess i just need to buy another one. |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 2166
Registered: 1-2001
| | Posted on Monday, October 20, 2003 - 3:34 pm: | |
Any of the combinations you mention is OK with test pipes:
1. If the test pipe manufacturer provided the thermocouple mount then that's fine to use (since there's no ignition source inside the exhaust to ignite unburned fuel it will never see a super-high temperature), or
2. Just tie them up somewhere -- they'll just always report a low (room) temperature to the ECU (and cap the mount if present).
In your case, I'd just leave it mounted as-is (why hassle with the cap?).
I've got to agree that modern complexity has it's downside. I'm sort of dreading ever owning an OBD-II F (and haven't completely ruled out going back to a hot-rodded carbed BB if I could just somehow get around the emission stuff).
|
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 51
Registered: 2-2003
| | Posted on Monday, October 20, 2003 - 3:10 pm: | |
The thermocouples are installed in the test pipes in the holes provided. is there a better way? can they be removed, tied out of the way, and the holes capped? if so, where the Heck do i get a tapered metric cap? if the thermocouple is damaged, it would send the same response to the ECU? yes, no, maybe????
i gotta say, my old 308gt4 was a LOT easier to live with... |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 2165
Registered: 1-2001
| | Posted on Monday, October 20, 2003 - 2:18 pm: | |
As "OK" as you can tell from the outside (the whole thing's a little iffy IMO even when it seems to be working). Are you having an operational problem (either with the warning lights or the engine management)? If your self-test works, the thermocouples are secured out of the way, and the warning lights aren't coming on erroneously, life should be good... |
James I. Movich (77_308gt4)
New member
Username: 77_308gt4
Post Number: 50
Registered: 2-2003
| | Posted on Monday, October 20, 2003 - 12:53 pm: | |
OK,
the lights work just like you describe - they come on with the other system lights, and go out after 2 or 3 seconds.
so that in itself means the ECUs are OK?
found them at $180 ea. (Sodacom's) |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 2164
Registered: 1-2001
| | Posted on Monday, October 20, 2003 - 12:37 pm: | |
The slowdown warning light self-test should be described in your OM (but it can be hard to find -- try the diagram with the number labels for the "Instruments and Controls"). Basically, the slowdown warning lights should come on when the ignition key is first turned "on" (the engine doesn't even need to be running) and then the warning lights should go off after a second or two. If the warning light(s) never come on, or stay lit, you've got a problem somewhere for sure.
No idea on thermocouple price, but you could check the prices at FerrariUK on cat-equipped 308/328/Mondial for comparison/reference (but your 348 probably has different cabling/connectors even though the basic internal thermo-voltaic device is probably the same). |
James I. Movich (77_308gt4)
New member
Username: 77_308gt4
Post Number: 49
Registered: 2-2003
| | Posted on Monday, October 20, 2003 - 12:27 pm: | |
BTW, what do the little thermocouples bugers cost each? |
James I. Movich (77_308gt4)
New member
Username: 77_308gt4
Post Number: 48
Registered: 2-2003
| | Posted on Monday, October 20, 2003 - 12:25 pm: | |
OK, steve, (against my better judgement), i'll bite....
how do i know if the self-test is or is not working correctly?
(i know this cant be good.... LOL...) |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 2163
Registered: 1-2001
| | Posted on Monday, October 20, 2003 - 12:01 pm: | |
If the self-test isn't working reliably -- i.e., the slowdown ECU(s) output is wacky -- then I doubt you'll be successful by trying to "fool" the input side of things, but measure the DC resistance of the thermocouple itself -- if it's "open" that's bad (but that would be the incredibly lucky fix). Unfortunately, I believe your 348 (unlike "dumb" 308s and TRs) does have an "intelligent connection" between the slowdown ECUs and the injection/ignition system. Ideally, to disable the influence of the slowdown light ECU, you'd identify this line/connection and what the "good" condition signal is (probably a +12V or ground signal), then supply this "good" signal artificially to that line.
What is your real problem? If your self-test isn't working (and it's not a power/ground/thermocouple problem), I think it would be better to just buy a new slowdown ECU (i.e., even on a car with test pipes, if the self-test wasn't working I'd still deduct ~$1K/side off the price) -- JMO... |
James I. Movich (77_308gt4)
New member
Username: 77_308gt4
Post Number: 47
Registered: 2-2003
| | Posted on Monday, October 20, 2003 - 10:09 am: | |
OK, Sorry, but i "gots to know". i get bits and peices of some of these by searching, but still need definitive answers.
Q.1 - is the ONLY purpose of the thermalcouple to sense high temps in the Cat?
Q.2 - is it the only sensor connected to the "slow down" lamps? if not, please explain in detail.
Q.3 - if yes, can it be jumped to keep it "off"? if jumped, explain if it is then open or closed, and how that affects other systems, if any.
Q.4 - is there a better solution than jumping it if it is not needed(test pipes installed).
Q.5 - what are all of the conditions that can cause loss of power to one bank?
Q.6 - what questions was i not smart enough to ask on this subject?
background info:
1990 TS.
Tubi and test pipes installed.
after driving, with everything up to full operating temps, the tubi is almost cool enough to place your hand on. the test pipes are slightly warmer, but not overly hot - a LOT cooler than the tail pipe on my ford bronco, say six feet down the line. (not that THAT is in anyway relevant, LOL) |