HELP!!! Early 88 Testarossa Gremlin!!

Does the engine keep running (on just the 1-6 bank) after the 7-12 ignition stops working, or does the engine stop running a few seconds after the 7-12 ignition stops working?

 

Beautiful car Joe, love the color. When you say "the ignition cuts out on the 7 - 12 bank after warm up and under load" does that mean you have determined its not a fuel problem and isolated to ignition, or do you mean that (entire?) bank stops running (could be fuel or ignition)? Also, "after warm up and under load" do you mean once warmed up and ONLY under a load, or does it occur once warmed up and at idle and/or under a load? Also does it do this consistently or intermittently? You mention fuel pumps and fuel distributor--what servicing was done to those? If happening at idle, determine if you have ignition pulses on that bank; connect a timing light to each of the 7-12 spark plug wires and ensure you are getting ignition pulses. If that checks good then move to the fuel system. Once warmed up and not running on 7-12 shut the car off and jump the L.H. fuel pump to see if it is operating (engine off/key on; relay "T" energizes the L.H. fuel pump).

I suspect you mean your symptoms are only occurring under a load...a little harder to diagnose. A quick check on the ignition side would be to swap coils and see if your problem moves with the coil. If fuel related could be an issue with the (new?) pump. I'm curious what was done to the fuel distributors. Could also be fuse panel related but I don't believe those gremlins normally occur only under a load.

If you can provide a little more information on your symptoms I'm confident we can help you track it down.

 

Great colors.

 

How are cables? Do they ohm out? Like Tim said above, check spark with a timing light. Ignition system is easier to rule out then look into fuel.

 

Nice car! I have a black with black leather 88.5 and had the same issue. After I verified it was not a fuel issue, I swapped the coils and the problem moved from 7-12 to 1-6 side so I purchased a new ignition coil, problem solved. My problem only showed up once the car was warm and I also had some intermittent backfiring that went away when I put in new coil. Sometimes when accelerating it would lack power and then suddenly kick in, must have been heat soaked intermittent coil issue.

 

same exact thing happened to mine. I have a thread with generic part numbers. I replaced both coils and modules for under $200

 

You can try swapping the ignition ECUs from side to side to see if the problem follows, and swap coils/final stage units side to side to see if the problem follows.
Most of the intermittent/no spark issues that I have seen on TRs were due to bad final stage units/coils, as they are the part that has the most load on it.

Brian Brown
San Francisco Motorsports

 

I had the exact same problem on my 91, swapping coils from side to side identified the issue in 20 minutes.

 

Hey Tim, any chance you could find your post and insert a link into this thread.

 

This was my part number summary and I link to another thread with more details.

https://www.ferrarichat.com/forum/threads/tr-anyone-buy-coils-recently.602871/

 

Why is it never easy

Have you measured the voltage on the yellow wires (terminal 15) of the 7-12 coil relative to ground? Does it stay +12V during both good running and bad running, or does it droop down during bad running?

The +12V power to the coils comes from a common source, but are split on the fuse-relay panel and pass thru separate terminals in the y horizontal white connector -- so wouldn't hurt to unplug/inspect/reseat that y connector. Since these G (yellow) wires in the y connector are +12V key switched sources, they are often (wrongly IMO) used when adding other electronics so have a look for any added mods/splices there, too.

(side note: 15KV sounds a little wimpy for an electronic ignition -- is this the voltage you are measuring to fire the spark plug air gap, or the maximum voltage that the system can deliver to a larger air gap? Can't say that I've ever seen a direct spec for this in the F literature.)

 

It sure seems like something "analog" in the 7-12 primary stuff/wiring since you report it does fire, but just weakly, during the bad running and being a sort of thermal-time-heats-up-to-failure. On the other side of the coil (terminal 1), the red wire at the coil should be switched by the power module from a good connection to an open connection to the black (ground) wire at the power module so you might check the black and red wires for good swagging to their respective terminals in the power module connector, and the black wire swagging/connection at the other end to the chassis.

Do you have a copy of Diagnosis Sheet No. 1? Since you've got access to the 25-pin test box, it would allow you to verify (or condemn ) the MicroPlex ECU operation. If not, give a shout and I can put it up on DropBox.

 

Sorry if this has been answered but... is this the original fuse panel? I wonder if the issue is due to heat buildup somewhere within the fuse panel’s layers from excessive resistance and potentially resulting in a temporary open until things cool down?

 

i was going to suggest checking the fuse panel too. I lost a bank last year, had to made a small repair on fuse panel connector. I also cleaned up the whole panel and all connections. Now the car starts better and windows rise faster and I guess it must be running better too.

 

Joe, dont use sprays for electronics, WD40 or other chemicals on the plastic layers of your OEM fusebox. It will destroy them in time and no repair will be possible.
Guido

 

I had the same problem with my low kms 89 and it was the EHA. The car would run great until warm then a power drop like flicking a switch and an idle that burbled. Keep in mind if the EHA was tested on the bench at room temperature it would pass the test.

 

Had a problem with similar symptoms when I got my 1988.5 TR. After full engine out service it would die (7-12 bank) after some minutes running. Electronic readings were really funny. Started strong from cold every single time. Turned out to be hairline fracture in round connector to ECU above rear passenger wheel where pins would ever so slightly pull out as the engine warmed up or vibrated. Replace both 24 and 9-pin round connectors to both ECU boxes and haven't had the problem since.

 

Hey Steve, concerning electronics, do you remember who on this board put electronic power steering on their TR?

 

Melvok in his 512TR (but I'd think it could also be made to work on a TR). Here's one of his posts that has several of his related links:

https://www.ferrarichat.com/forum/threads/proud-new-owner-of-a-512tr.412811/#post-142392089

and this one shows the US link for ezsteering (click on the US flag):

https://www.ferrarichat.com/forum/posts/143632739