88 Testarossa stumbles for 10-15 seconds upon cold start

Battery light is normal, as the alternator requires an initial "excitation" (sorry for the poor english). So it will not go off untill you've reached at least once a certain level of rpm. From then on it may pop-up again if idling very low.

If your car is on k-jet, there is a sweet spot to be identified in terms of cold control pressure and thermo time switch duration, so as to enrich sufficiently the engine, but not too much.

Mine is a bit on the lean side during cold startup and it indeed takes a bit of time to "clear" the idle. Also my fast idle valves are a bit sluggish, so do not raise idle sufficiently to compensate for this initial lean mixture.

I personnaly reluctantly enrich the cold startup mixture, because although it improves idling it also generate obnoxious fumes... So a rough idle for a 30 seconds seems a better compromise. I would consequently be more than happy if the fast idle valves could keep idle higher during this initial period.

 

(There's no "control pressure" on a KE-Jet US version TR.)

Sure looks like you have a dead bank at cold start-up -- either a dead fuel pump or a dead bank of ignition. (but then maybe it gets going like if you use the running bank to get the alternator going so the voltage goes up and then the dead bank gets going). Have you done anything to fix the known degraded connections for the fuel pumps in the y white connector? If not, have you unplugged and inspected the y white connector female terminals for the fuel pumps? If those seem OK = you should probably use a timing light (or spark tester) to rule the ignition system in, or out, first.

PS One of your slowdown warning light ECUs looks dead.

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Yes, just like in the photo -- discoloration of the white plastic around the end of the female terminal (which can't be seen when they are plugged in), and the "prong" ends of the female terminal being spaced apart and not touching each other in the free state.

Yes, that's correct. There's no safety issue if you have no catalytic structures in the exhaust system to ignite unburned fuel+air, but, if I was a Buyer of your car, I wouldn't call it a good thing, and would deduct the cost to replace it from my offer .

 

Yes, someone has already done "something" to bypass those (probably crispified) fuel pump terminals -- you'll have to investigate and probably do a better repair. Things like "crimp" terminals (to join wires) or just twisting the wires together without soldering don't work very well because the current is so high (like 10A). The bottom line is that you need some form of wiring from terminal 30 of the fuel pump relays to the beige (P) and beige-black (PN) wires (that were originally in the y connector) going to the fuel pumps that can carry a high current reliably.

 

Yes, the female terminals would need to be replaced, and you should look at the male terminals on the PCB -- those often get destroyed, too, as well as the PCB traces in the male terminal area. But going back to stock is just going to guarantee the same problem in the future. IMO, you should get either:

1. Guido's TR PCBA (that has robust wires and better connectors)
or
2. GT Car Parts TR PCBA (that has thicker traces).

 

Start conversation with theunissenguido (I hope he still sells them -- red bay cars link seems dead).

https://www.ferrarichat.com/forum/posts/146089664

 

The SRI modifications is OK, but the added relays are mounted behind the stock fuse-relay panel (so are rather unaccessible), and there should be another small fuse panel added on the RH side -- do you have that? Your picture wasn't wide enough to show it, but this the SRI modification:

(doing an edit to add the picture -- please wait)

 

(Couldn't get it all done in the 20 minute editing window so I'll repost.)

The SRI modification is OK, but the added relays are mounted on the backside of the stock fuse-relay panel (so are rather inaccessible) and there should be another small fuse panel added on the RH side (plus some of the stock fuses would be missing) -- do you have that? It's a much more "obvious" modification -- it works, but I'm not a fan. Your picture wasn't wide enough to show it, but this the SRI modification (note the added fuses, the missing stock fuses, and the extra wires connected to some "faux" relay bodies) :

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This is the backside with the added relays:
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And here are some shots of it as installed (it seems to have undergone some small changes over the years):

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Can you post a photo of your entire fuse-relay panel? If you do have the SRI modification and a fuel pump is not working could be a bad relay or a bad wiring connection somewhere (if the fuel pump itself is OK.)

 

Yes, that seems to be SRI (plus a few other mods).

 

you don't need fuses in the top row where there are red highlights. those are the ones that SRI reroutes.

 

I don't think they are connected to anything. SRI rewires the fusebox and reroutes those wires. Those are just spare fuse holders now.