| Author |
Message |
Peter Polasek (Peterp)
Junior Member
Username: Peterp
Post Number: 92
Registered: 8-2002
| | Posted on Saturday, May 10, 2003 - 7:02 am: | |
Kurt -- BTW, thanks for your posting a long time ago with instructions to properly set the throttle stop screw. I knew that mine had been changed by the previous owner and searched the archives for how to set it. Your post seems to be the only mention of this procedure, and it worked great for my car. It is buried in an "All Mondials" thread:
http://www.ferrarichat.com/discus/messages/21/606.html
(search with ctrl-F for 450 to find the procedure)
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Kurt Kjelgaard (Kurtk328)
Junior Member
Username: Kurtk328
Post Number: 195
Registered: 3-2001
| | Posted on Wednesday, May 07, 2003 - 5:12 am: | |
Lawrence, of course you're right - my mind must have been elsewhere.
Sorry for the confusion. |
Rob Baylor (Baylor308)
New member
Username: Baylor308
Post Number: 14
Registered: 11-2002
| | Posted on Tuesday, May 06, 2003 - 12:44 pm: | |
I have an 85 308 QV, which I believe uses the same injection system as the 328.
It is a K-Jetronic with lambda.
My car also surges at idle and low rpms when driving. As the rpms increase (~2500 rpm) the surging rate increases to a point that I can't feel it anymore.
Maybe it's just me but I notice a change in the way my car runs about twice a year and have accepted that I have to tweak the fuel mixture to fix it. I'm not positive but it might have something to do with when the oil companies start oxygenating the gasoline to help with emission in the winter, and stop in the summer.
Get copies of any of the following books to learn more about the K-jetronic system:
"Solving Bosch Continuous Injection System (CIS) Problems" by James Weber, Marketed by Future Education, Inc. (800) 475-0727
"Gasoline Fuel-Injection System K-Jetronic" by Bosch, #1 987 722 159
"How to Tune and Modify Bosch Fuel Injection", by Ben Watson, Published by Motor Books International 800 826-6600 www.motorbooks.com
"Bosch Fuel Injection & Engine Management" by Charles O. Probst, Published by Robert Bently 800 423-4595 www.rb.com
Rob Baylor
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Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1758
Registered: 1-2001
| | Posted on Tuesday, May 06, 2003 - 12:14 pm: | |
One function of the throttle microswitch on the TR is to tell the injection ECUs to limit the amount of mixture tweaking at idle to minimize RPM changes (even though the O2 sensor outputs may say otherwise) -- does the 328 have any similar such device/scheme? (And what is the 328 injection anyway -- K-Jet with Lambda?) |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 593
Registered: 4-2002
| | Posted on Tuesday, May 06, 2003 - 12:08 pm: | |
Isn't the disk right under the airbox? In that case I find it hard to imagine that it moves up to measure air flow. Air flow would push it down. The disk is several inches in diameter.
Haven't looked at my 328 in quite a while so I could be remembering incorrectly. |
Kurt Kjelgaard (Kurtk328)
Junior Member
Username: Kurtk328
Post Number: 194
Registered: 3-2001
| | Posted on Tuesday, May 06, 2003 - 11:55 am: | |
For info: The Ferrari systems work "upside down". The sensor plate moves up, not down.
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Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 592
Registered: 4-2002
| | Posted on Tuesday, May 06, 2003 - 7:17 am: | |
The 328 injection system is the same as the old Mercedes system. I have an old 450. There is a disk in the venturi area where the airflow is measured. Residue builds up around the periphery of the disk. If this is your problem, get some carburettor cleaner (O2 sensor safe) and spray it on a rag. Gently push the disk down and clean the walls of the channel around it. Mine was very dirty on my MB causing the idle to wander about. Hope this helps. |
Peter Polasek (Peterp)
Junior Member
Username: Peterp
Post Number: 88
Registered: 8-2002
| | Posted on Tuesday, May 06, 2003 - 5:31 am: | |
The O2 sensor is famous for a surging idle in these cars. You can probably "fix" it by disconnecting the sensor - many people believe this is the best thing to do as a permanent solution, so it's certainly safe to disconnect it temporarily as a test. My car came with the O2 sensor disconnected because the previous owner said that was the only way to eliminate a surging idle. The first thing I did was purchase and install a new O2 sensor. It does surge slightly at idle, probably +/- 10 RPM, but I feel more comfortable with the sensor in place to ensure it is running at the correct mixture. It is debatable whether a slight surge is normal -- I recently read a Ferrari book that stated "you can detect the lamda-sensored Ferrari engine by the surging idle" -- but others on this forum don't believe it to be normal.
None of this explains why your car just started to surge -- have you done anything to the O2 sensor or fuel injection recently? The obvious conclusion would be that the O2 sensor is bad, but I think the surging is an indication that it is working because it is adjusting the mixture. I'm no expert, just commenting on what I have experienced and read, but I would definitely disconnect the sensor temporarily to see if the surging goes away as a first step. |
Omar (Auraraptor)
Member
Username: Auraraptor
Post Number: 526
Registered: 9-2002
| | Posted on Monday, May 05, 2003 - 11:11 pm: | |
My 633CSi started doing that...surging from 1000-1100 over and over at idle. I forget what, but its nothing major, just something needs an adjustment. Hope someone here can better help you.
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Mark A.Diaz (Zaidria)
New member
Username: Zaidria
Post Number: 15
Registered: 5-2002
| | Posted on Monday, May 05, 2003 - 9:47 pm: | |
My 328 just started having a slight surge at low idle. It used to be smooth. Now at around 1100 RPM (idle) is will surge about 150 RPM, up and down, takes about 3 seconds for the cycle. Other than that she runs like a scalded dog!
Any advice?? |