Hi, I am not bringing my 328 to a mechanic again. Below is what he did and the symptoms: ****** What he did ******* I want him to fix the long cranking problem when starting the engine (cold or warm). He said "fuel check valve" (FCV for short) or "crank position sensor" (CPS for short) could be the culprit. Next he said fuel check valve looks fine. One of the two crank position sensors needs replacing. (note, according to Birdman, on 328 there is only one CPS) Then he said parts supplier send the CPS for 308 instead of 328. He can modify it to fit my 328. (note, on Ricambi web site, 308 and 328 use same CPS, part#119052). $500 burnt to ashes. He said I need to go back to replace the FCV. (I thought, didn't you say FCV looks okay?) ****** Symptoms ******* 1. Still long cranking to start the engine. 2. New problem, on changing gears, RPM would drop below 500 to where the generator warning light (the red light to the lower right of the RPM Counter) starts to blink. 3. #2 above got worse, after about 10 miles driving yesterday (Dec. 27, 2009) I was going downhill and pressed clutch to the floor and let gravity pull the car. While doing that, the engine stopped twice. I was lucky not to have been on a highway. ********************** Gentlemen, I have a question: If the mechanic had mistakenly replaced TDC sensor (part#128364) with a CPS; would that be the source of my #2 and #3 problem above? I am, definitely, not going to let that mechanic touch my car again.
Did he check the fuel pressure? While cranking and also after the car sits for a while. If the pressure drops it can be a couple of things. Fuel pump or the check valve. Also check the injectors.
You need to find out if the engine is losing spark or fuel. I wouldn't go back to that place again either.
A way to test if it is a fuel check valve/long cranking problem is to let the fuel pump run for a few seconds before cranking. This requires unplugging the blue safety connector on the fuel metering unit. There's quite a few threads about that on here. If running the pump before cranking doesn't make any difference, I would look elsewhere, although it apparently still could be the fuel accumulator. This test isn't bulletproof, but is cheap and easy. Common sources of fuel pressure drop can be leaky injectors, bad check valve, or bad fuel accumulator.
Hi furnacerepair and Brian_Harper, So there are the following places to look: 1. Fuel pump 2. Fuel check valve 3. Injectors 4. Engine losing spark Also, is this the blue safety connector on the fuel metering unit? I am thinking it is although it is black. Thanks! Image Unavailable, Please Login
crack the throttle and see if it fires up faster. if so i would think the wur is bad. ( warm up regulator)
FYI, the plug you circled in your photo provides power to the Frequency Valve. Unplugging it will definitely not help your problem. I just had to replace mine and the relay that feeds it power. As stated by MustardFJ40 you have the plug to look for in your photo. Its on the FAR right of the photo just barely in the field of view. It is colored bright blue. Good luck!!! Hope this helps. PDG
I agree with Carreaper.. crack the throttle and see what happens. Your WUR may be on the way out. Sounds like you have a fuel pressure problem at startup. You should also ask your mechanic if he adjusted the idle. Your stalling may be a result of idle too low after warmup. WUR should keep it idling fine at cold start, assuming it's functioning good enough. If it ran fine before he "fixed it" (other than the hard start), then it should be an easy fix. This may help: http://ferrari.cdyn.com/carl_rose_docs/Ferrari%20328%20CIS%20Fuel%20Pressure%20Check%20with%20Pixs.pdf
cracking the throttle increases the vacuum pressure to the metering plate, a better test is to check the rest position of the plate and see if it's correct. you could also move the plate about 1mm down with your finger while someone starts the car and see if that helps. usually the problem is an incorrect plate position and that will create hard starts and idle issues. any testing of the fuel system really requires gauges to see pressures and make sure it's right. from your description I'd look at the plate position first since this is a cold & hot problem along with a non-loaded one. also the crank sensors are for ignition sequence nothing to do with the fuel system as that is run hydrolicly and constant. any back ground? when it started? added: the fact that it runs fine until you let it idle down tells me that your safety switch is OK. if the engine runs normal other than start and idle look first at the metering plate, the top edge should sit right at the break point or within 1mm of the top leading edge but not have any of the funnel visible. it's adjusted by knocking down a pin next to the distributor body. if your not comfortable with adjusting it if needed, find an old mercedes repair shop as the CIS systems are the same and the older mercedes guys will have the tools and know how on the system.
Summarizing strategies on tackling the problems of long cranking time and idle down to engine stop are: A. Fuel related: .....1. Fuel pump .....2. Fuel check valve .....3. Injectors .....4. Fuel accumulator .....5. Warm up regulator .....6. Fuel metering unit .....7. Metering plate B. Electrical related .....1. Engine losing spark Hi thecarreaper, Cracking the throttle did make the engine fire up faster. So if I need to replace the WUR, where would I buy one? I hope it's not Ferrari specific (OEM). Hi speedy, Can you tell me about where (use the blue fonts to point out) I can find the metering plate you are describing? Image Unavailable, Please Login
The metering plate is under your air filter box (Q1 on the grid). Loosen the accordion hose connected to the air filter box, then undo the lid and take it off. The metering plate is under the air filter itself, down inside. I usually take off the entire filter box for easier access. It should just slip off with a little lateral twisting action. NOTE: the Probst book is a great guide for getting to know how your CIS system works. http://www.amazon.com/Bosch-Fuel-Injection-Engine-Management/dp/0837603005
