348MondialT Idle problem

My car is having a problem at startup and idle.

At startup: For years the car has started
reliably on the second try. Now, I am having to
try 4-5 times. Each time, the engine will sputter
and start to catch but then die. This morning
(cold start) I had to press the accelerator while
it was sputtering so that it would settle out.
After a few (5-ish) seconds at 2500 RPM it held
idle with an occasional sputter.

Here's what I checked:
1. Noticed that the 5-8 bank was not blowing as
much exhaust as the 1-4 bank. It was at 1/2 or
less CFM (judging by feel against my hand at
the exhaust tips). Decided to check the ECU
codes because I had gotten intermittent check
engine indications yesterday while driving, but
while I was walking to the bench to pick up a
screwdriver the engine suddenly increased its
idle dramatically (circa 1500 rpm versus the
usual 1000) and dropped back down. At this
point the problem has swapped sides and the
1-4 bank was not blowing strong but the other
was. After another several seconds everything
equalized and the idle was smooth. I didn't do
anything during this time so it is rather
confusing to me.
2. Pinched the idle air motor intake hose to see
if the engine would stall ... Yup, that worked.
So I presume from this that the idle air motors
are doing their job (i.e., feeding air during
warmup).
3. Checked for tight elect. connections at the
MAS, throttle position sensors, and the harness
attachment on the engine driver side rail. All
seemed good.
4. Checked the ECU codes. 1-4 bank gave 1-1-1-4
(lambda sensor), which is fairly common and has
never been an issue in the past. 5-8 bank gave
1-2-1-1 (lambda regulation), also seen occasionally
for well over a year with no ill effect. I
replaced the O2 sensors last year anyway. It
had reduced the incidence of these codes but
not entirely eliminated them.
5. Let the car warm up till the coolant fans
came on, then drove it 15 mins up the road. Ran
beautifully. Parked for 10 mins to handle something,
came back out and again took 4 tries to start
it up in spite of being well warmed.

Issue at idle:
On short trips, about 5 minutes into the trip the
engine will want to stall at stop lights. I have
to old idle by pressing the accelerator slightly.
Problem goes away about 15 mins into a trip. I
also noticed that during this period the car will
also hesitate occasionally while cruising at a
steady 35mph during in-town driving.

What should I check next? My thoughts were:
(a) fresh gas, (b) reset the ECUs and hope for
the best, (c) poll for advise here. I started
with c :-) while I work on the others in parallel.
Thanks for taking the time to read this.


Lou

Update on this: This evening (8 hrs later than the above issue with starting) the car started fine. On the drive home from work, the check engine 1-4 light came on and this time it stayed on. Car felt good, no notable issues. Checked the ECU code when I arrived home. Was 1212 ... never seen that one on my car before. The workshop manual lists two meanings for this:
1. "Additive value for self-adaption Lambda regulation".
2. "Multiplicative value for self-adaptation Lambda regulation".

I'm lost as to the message this code is trying to tell me. :-(


Lou

Okay what you need to do first is try resetting the ecu's. Do this after the car has sat all night. You want to make sure that the engine is cold. Disconnect the battery, and wait about :30 seconds. Reconnect the battery. Now turn the key to the on possition and wait. Listen for the fuel pumps to stop. Make sure that they have fully pressurized the fuel rails. Okay now start the engine but, DO NOT TOUCH ANYTHING. Don't touch the throttle, the break, the clutch, nothing. You will want to let the car warm up on it's own so that the ecu can relearn the warm up process. Let it sit and idle for at least 15 minutes. That is plenty time for the ecu's to calibrate themselves.

Thanks Ernie. I had worked on this most of the day yesterday chasing anything that I could associate with getting air into the engine. It turns out that the problem disappeared after I cleaned and reseated the electrical connections to the MAS and the throttle position sensors. I also cleaned and relubed my air filter. I drove it for about 2 hrs last nite with no issues. Started up normally this morning also.

Glad to hear you got it sorted out.

Thanks Ferrarilou,
i got the same problem, but in my case the 4 bolts and washers where the throttle position sensors is mounted were loose, so I cleaned it, remove the paint and what should i say it runs perfect now, other problem i have is: how can i recharge my a/c i can't find any fitting for refill like on the 348, my car is a 94' mondial t, also in germany freon is forbidden here since year, what should i do,

thanks so much for your input

marcus

Hi,
you got to fit a retro set from underneath the engine. Screw out the two old valves (same as tire valves), then fit the adaptors. Cheap at any local car supply dealer. Don’t say it is for a Ferrari…
The system has to be evacuated using one of these automatic machines available at any large workshop, which takes about 15 minutes. While doing this, it is checked for leaks. Then, and this is important, a special retrofit oil which prevents any left over of the old lubricant from clogging has to be added. Next the correct amount of R134a has to be filled in, while doing this the engine should idle with the A/C switched on and set to Max.

If anything went OK, you will experience the coldest Mondial ever. Other than often mentioned, the R134a is not worse than the old R12. Indeed it is more effective in a wide range!

The equipment needed is not Ferrari specific.
I had it done at a Toyota dealer for a few Euros!

Chris