Ferrari 308 hot start problems

Mike, I experienced the exact same issue with my '82. If I remember correctly (forgive me, I'm in no way a technician) the primary culprit in my case were the injectors, which were spitting too much fuel as opposed to misting the cylinder. I also believe that the diaphragm under the air filter needed adjustment . . . so that it seated properly and was not left open.
Once addressed I've never had a single issue since. The car starts on one twist of the ignition hot or cold.

 

Since you already replaced the injectors, I guess we can rule that out. The next is to check the control pressure at the WUR. You will need a set up for that.

 

if you already replaced all of the above...check if your "new" fuel pump has a non-return/ cut off/check-valve ...if not, that is likely your problem


http://www.ferrarichat.com/forum/308-328/334988-89-328-hard-start-when-warm.html

 

Highly recommend the book "Bosch Fuel Injection & Engine Management" by Charles Probst. Easy to find and it has a whole chapter on troubleshooting the CIS system. I'm currently tracking down a similar problem in my QV.

 

I don't know your set up, but my 86 328 WUR was the culprit for difficult hot starts.

 

I had the same problem with a Mondial I used to own. The local trained mechanic wanted to replace the fuel injection system at a large cost. So I took it to a everyday car type mechanic and he replaced the crank sensor. Never had another problem.

Good Luck

 

Mike, next time this happens, disconnect the cold start injector and try again. There is good probability that the injector is running even though the engine is hot.

 

amen m souza. my 81 was cured by disconnecting the cold start injector. since it starts ok cold without the extra fuel i haven't replaced the injector yet. i think after 32 years the injectors are allowed to leak. jon s

 

Electrical connector on WUR caused me some prob's.

 

am having the same hot start problem on my 82 308GTSi. I will get it hot again tomorrow and try disconnecting the Cold Start injector. What is a WUR?

 

I went through all those easier more obvious swaps and pressure checks over a period of about 2 years. It got to be that I was afraid to turn the ignition off when I stopped for gas. Then one day I noticed that the relay for the fuel pump was getting REALLY REALLY hot. I changed the fuel pump (which had been tested as being ok) and that instantly solved the problem (for over 5 years now since then).

 

Warm Up Regulator.

 

Thanks for the info Mike. From where did you source your Fuel Pump may I ask?

 

It's a standard 0580254975 Bosch part (for my USA 1984 QV) common to a Mercedes 280 SE, so you don't have to get them through a Ferrari supplier... I happened to get them from Mercedes, BMW items in AutoLampsPlus store on eBay! at the time and it was way cheaper than buying from one the usual F-car parts suppliers I often use... it was $155 plus shipping which saved me around $100 at the time. They're still selling for within a few dollars of when I bought mine late in 2008... click here for an example.

 

Just as ALL male human bodies will eventually get prostrate problems, ALL injection 308s will eventually get warm up start problems.

In general it relates to excessive fuel into a hot injection air box, flooding the engine. A 15-20 minutes wait will allow normal restart...about enough time for AAA to get there for an unnecessary tow.

In my case the cause was a faulty THERMO-TIME Switch, one of the devices which energizes the cold start injector. GL


Ferrari Wiring Diagrams