Hi, I had a strange symptom when I took my 1990 Testarossa out for its regular run recently & appreciate any thoughts. I headed out & drove about 30 minutes to my regular coffee place & all went perfectly. It was quite a hot day & the car was in parked in the sun for about 1.5 hours. When I left to come home it started quickly as usual but when I took off it seemed really sluggish & certainly didn't have the usual powerful acceleration. No unusual noises & idle at the traffic lights seemed normal, just really down on power. I was driving on the main highway (about 5 minutes after leaving the coffee place) at about 80kph (50mph) debating what to do & listening for any unusual sounds & watching all the gauges (also all normal) when suddenly it took off & the acceleration & power was perfectly normal again. No strange noises or changes to the gauges when it changed back to normal. The road was also totally smooth & I was just cruising so I don't think it would be a bad connection, etc. If it was sitting in the sun for 1.5 hours (which I normally don't do - I only take it out on cooler days & never in the rain) that caused it, isn't it strange it took 5 minutes of driving for it to come back to life? Anyway, I would really appreciate any thoughts or suggestions. Cheers, Gary.
Your car possibly went to working on one bank of cylinders for a short time. The car will run smoothly, but rev slowly. Why is the difficult question. There are several possibilities. Possibly an electrical connector somewhere in the engine bay or a connector in the fuse box, but it could also be an ignition issue - a wire, coil, cap, rotor, etc. First problem is diagnosing which bank is acting up. I use a timing gun with a strobe light for that. Then, in the absence of something obvious, comes the fun of swapping parts left to right until the problem moves to the other side.
I had a loose connection to a fuel pump relay that caused a similar problem. The car went from running normal to running on 6 cylinders. Nice and smooth on 6 cylinders, but obviously down on power. And then BOOM....all of the sudden back to 12 cylinders and life is good! My fuel pump relays have been modified by a previous owner with jumpers that move the relays away from the fuse panel. This was done in an effort to prevent the relay failures which I understand to be common. One of the jumper wires came loose and that caused the intermittent fuel pump failure. Your issue sounds like a loose electrical connection that affects either fuel or spark. My car is a 1989 US-spec.
Very common symptom on TR. Pull the connector for the fuel pump power supply at the fuse board and look for discoloration.
Thanks everyone for the suggestions - I guess I have to wait for it to happen again to do some diagnostics. Looking at the fuse/relay diagrams I can see that the Fuel pumps are fuse 19 & 20 and relays R & T. Are there any wires on the large connectors (below the relays) that go to the fuel pumps so that I can test for voltage? I seem to recall reading somewhere that you could tell if a bank wasn't working by feeling each exhaust pipe (or something?) - is that right? Cheers, Gary.
I would not put your hand on it - but yes, a laser thermometer works, but not if it has been running a while on 12 before the issue arises. If the issue is spark related, a simple timing gun attached to a plug wire on each bank will tell the story.
