Ran a thread on the above in another segment, with limited success- I was suggested to try here. my car-92-55 kil. When cold will take two to three cranks before starting- that is it will fire up every time but die. The third or frouth time it will stabilize itself and I will be good, runs very smoothly otherwise. Hot start, perfect, luke warm start perfect, barely warm start,perfect. Now, every so often, it will start and stabilize when cold,first time, but that is rather an exception. What should I look for? Also, at this time, engine undergoing major service. Below is the list of what is being done: replace valve cover gaskets,cam seals,cam gaskets,cam bolt oil seals and front crank seal replace complete water pump kit replace all belts: a-c,alternator,air pump, timing along with bearing rollers replace air filters, fuel filters,spark plugs and exhaust gaskets replace both thermostats with gasket kits oil and filter service gear-transmission oil change coolant flush break flush and servicing of calipers adjust valves as required any suggestion as to what might be missing, or should be done?Anything in view of the above cold start issue that should be explored or fixed as the engine is out? thks
Kind of an unusual problem for a 512. That engine management version is pretty good. Since the motor is out and everything is easy to get to have them pull and clean every single connector for the engine management system. The main 2 big ones for the ECU's too. Then put it all together and see what happens. There is nothing else really that is easier to do now than later after it runs again. You might get lucky. Just curious, is this car new to you? The reason I ask is it might have other subtle issues that you might not be noticing because you never drove it in their absense. Also check all the hoses on the intake system after the MAF for possible intake leaks. Motronic can correct very well for leaks when hot but could be lean enough with leaks to be a problem cold. And after it runs test the various intake gaskets for leaks too.
Had the car for three years-euro model. No issues whatsoever.When i dropped the car for major service, they all said runs very smoothly,etc. And as they deassemble-they said all looks good and normal. had the starter issue-hot...followed the tread, and i now know what to do with that one. only other thing would be: very randomly and very very rarely, i drive, stable speed-say 120 kil-hrs for a while...and i get what feels like a shut down of one of the cylinder bank-right or left, dont know and within a few seconds,it kicks in again all all seem to be normal.Then I accelerate, decelerate,rev up, go fast,go mid speed...all remains normal.Like last summer, what i just described might have happened once in 5000 kilometers. Thats all i can offer. Frankly besides the above this engine runs very smoothly.
512 is wired wierd. The 2 Motronics are powered off 2 different contacts in the ignition switch. If the switch is headed south it might be occasionally losing connection to one. Might explain both problems.
My 1992 512TR has experienced the same starting issue that you're having. The problem appeared about seven years ago about a year after acquiring the car. It's been driven fairly regularily as it had 19,000 miles then and just turned 40,000. I had the engine out myself 2 1/2 yrs. ago and did everything major you're having done now plus quite a bit more. None of this work will address the starting issue and in my opinion it is lack of fuel to the cylinders on the cold, initial start. Some have suggested that it is a check valve or valves in the fuel system leaking back and leaving no fuel at the injectors after being parked for a while. After it once starts and goes through the oscillations of rpm which quickly narrow to a smooth idle, further starts that day are quick and easy. One suggestion I received which seems to help is to turn the key on for about 20 seconds, turn it off, back on for 15 or 20 seconds, turn it on and start. Many times this results in a smooth start on the first try. If it doesn't start on the first try it always does seems to reduce the number of attempts required. In these hurried times, this 45 second window seems an eternity but I try to force myself to do it. If someone has suggestions, I'm sure open to listen. I do firmly believe it's a lack of fuel issue, but could be wrong. Ron Judy
Thks, Ron i must admit I have at various time suspected fuel lack issue. The 512 shop manual shows a non return valve at the head of each pump, could that be the malfunctionning element? I have asked the mechanic, to also do what Rifeldriver has suggested. As for the full service, what else have you done that would be worthwhile considering?
In my opinion these check valves are leaking back, and after several tries with the starter the fuel finally gets to the injectors. I believe turning the ignition key on and back off like I'm doing finally gets fuel to the cylinders. This is just my own opinion that certainly doesn't have much basis to back it up. The 512TR is different than the Testarossa and there have been several threads on the same issue and cures for their priming problems on cold starts. The only other thing I've done is what a Ferrari mechanic suggested. I added a strong injector cleaner (forgotten the name) to the fuel after the tanks were down to about five gallons and drove it at high rpm until the fuel was nearly gone. Did this; no apparent help. Brian's suggestion of the ignition switch going bad has merit but wonder why the problem is gone after the engine has warmed up as little as 30 seconds. I very briefly lost one bank of cylinders only one time and that was quite a few years ago. As I recall it was one of the Bosch oxygen sensors in the exhaust system. I have test pipes in place of the cats and I gutted the pre-cats. I had a couple of oxygen sensor problems but with replacements it's all cleared up and the engine has been very strong with absolutely no problems for 5 or 6 years. Ron
I have had the same cold start problem with my 512TR since I acquired it in 2001. It would start, die and then on re-start stumble and get faster until finally catching. I replaced my fuse box with the Scuderia Rampante upgrade and this problem has been significantly improved (no other changes), leading me to believe it might be a problem with power to the fuel pumps.
I have the same problem, been trying to find out what is causing to no avail. Checked for vaccuum leaks, fuel pump is new, fuel pressure regulators new, coil packs and cables are new. Only thing I dont have connected is the catalyst thermocouple sensor (I have an aftermarket exhaust with sports cats and no place for the thermo bung to go in) - though im not sure this would impact the starting in any way. the other issue I face is every once in a while (randomly) the car would decide to cut off power as i accelerate at around precisely 5500 rpm, as if I hit the limiter it would hold back and stop revving beyond. The issue is hard to replicate as it comes up on its own and I have taken a video of it. Dealer cant replicate either as when they test all is fine (including fuel pressure tests and hold). They are now blaming the exhaust and saying the ECU reader is showing out of range/inconsistent reading for the exhaust temp because of the bung being disconnected. anyone know what the input (or lack thereof) of the exhaust thermocouple would do to the motronic system and if this can be sorted in any way other than swapping back to the original exhaust/cats?
Forgot to mention, my car is a Euro 1995 F512M. I used to own a 512TR before it and never faced these issues.
The tachs are known to start to be lazy as they age .. are you sure you are truly not hitting the limit ..had this with mine Sent from my moto g power using Tapatalk
Nope, unlikely to be the case as most of the time its fine and revs normally (all the way). Also this feels different to a redline. Also wouldn't explain the cold startup issue… if they are related in any way
