First of all, the car is a 348 TB from 1990. ECU's have been changed at some point and are labeled as "Mondial T 1989, 2.7". So, as I mentioned in the picture thread, I seemed to have no spark or very thin spark on the left side. Today, we diagnosed with a friend, we checked (and compared with right side): -Voltage to the coils -Groundings to the ignition module -Connections between the ECU and the ignition module -ECU power and ground connections -That the ignition wires go to the correct plugs -We changed the plugs on the left side (brand new NGK ones) -Measured the ignition control and the coil control with oscilloscope -MAF voltages -MAF groundings -Throttle position switch After checking all this, we did find a proper spark on the left side. We also found out that the injector relay for the left side has been jamming and was also warming up. It might have been playing its part on the story. However, we did get the left side also running and the car running on all 8 cylinders. But, after getting it running with all 8 cyls, we found out that the ingition problem wasn't the only problem. We did get the car running, but it runs badly. It : -Doesn't idle -Gives out black smoke -Has no power and -Shoots on the exhaust (sounds like a rifle) The mysterious thing is that it's still even. The symptoms seem the same on both sides. After giving quite much thought to it, all we could come up is that the car either runs on freaking rich, or has timing problems. What we could think of that would/could affect both sides could/would be: -Some junk in the gasoline, clogging the return lines, hence raising the fuel pressure on both sides (though this probably would end up being uneven effect) -Throttle Position Switch, as this car has only the one idle-normal-WOT -staged switch. -Bad gasoline (so we filled up the tank) -Jumped timing belt (not enough to hit the valves, but enough to mess up running) -Bad voltages/groundings on somewhere (though we did measure a bunch of connections)? We did measure the temperature sensors with a hot engine, they gave around 440ohms both. When the engine was about hand-warm, they measured as 1,3kohm both. We measured this from the ECU connectors. Any other thoughts of where/what the fault might be? Is there any reasonable way to check the timing without dropping the engine?
I have heard of or seen cars out here with timing off sometimes a tooth, but none of those caused the severity issues I hear you report. Its possible I suppose, I am just saying I have not read about that. Very little tolerance before the valves interfere. If left running and the car gets to operating temps, if possible, do the issues still persist at normal engine temps? Crank sensors are an easy thing to check additionally, also the water temp sensors before you do fuel pressure tests etc. Just a thought, it may be worth checking those voltages from the ecu pins as the components may be fine but it could be wiring connections and the ecu not seeing it correctly. Just a thought, probably long shot but lots can be done before dropping it. Was it running right before or did it never run right since you had it? I'm sure others may have mare useful input.
Yes, the problem persists. We also did a test-drive the car, which let us know the loss of power. Is it physically possible for them or the trigger wheel to get misaligned in a way that it changes the timing, but still gives signal? Both banks are firing ok and the rev counter shows reasonable results, so it sounds like they do give information. But if they give the information at wrong time, it would make mystical effects. Measured from the ECU connectors, both gave ~1,3kohm when engine was about hand-warm and ~400ohms when the engine was warm. Hmm true. We did measure the resistance from the ECU connector (ie. unplug the ECU, put wires on the correct pins on the connector), but if there's bad connection between the ECU and the connector, it wouldn't show up this way. The car ran nicely last summer, I drove 3000km. At the end of the summer, the problem started and it showed like it was loosing ignition on the left side. I then changed the coil pack, ignition module on the left side and all spark plugs. Come winter, I concentrated on the winter cars, late spring, I just started to investigate this again yesterday. Today my friend (who is a professional car electrician, so he has very helpful toolkit and knowledge) came over. We traced the sparks and got all 8 running, but very badly. Oh, and I did disconnect the fuel return line of the left side and blowed in to check if it's jammed, was not. Also I've heard that the FPR's tend to break in a way that there. ...and I was about to write that another friend told me that the FPR's break in a way that they start pushing gasoline out from the vacuum line. I did earlier disconnect the left one and let the fuel pump prime the system and the line was dry, but I realized now that I never checked the right one. Went back to garage, disconnected both FPR vacuum lines and turned on the ignition (without starting) to let the fuel pumps prime the system (which should be enough). Both dry, but I decided to turn the engine a bit and started, shut down quickly and went to look. Voilá, the left one was dripping fuel. So, it seems that my left FPR is gone. Luckily I've heard that these are easy to find...not. But it sounds reasonable - as the regulation is not working correctly on the left side, it floods and kills the spark plugs, which leads to loss of sparks. It also pushes fuel to the plenum which enrichens the mixture even more. I think it shouldn't get the fuel from there to the right side as the plenum as the plenum has 2 chambers, but it might still be possible to extra-enrichen also the right side via the vacuum line. Step 1: find and replace the left FPR. Step 2: test and continue diagnosis if the problem persists.
Double check which FPR your cars has. Generally it is the Standard Motor Products PR161 xref for the barbed 3.0 car version. But the MondialT and the early TS had 3.8 bar for a short period of time before going to the 3.0 bar I believe, or so says the Bosch catalog. Confirm the stamping on it. I am having doubts that is the issue though.
I'd be more worried if it wasn't warm. A constantly energised relay should be quite warm. You didn't mention fuel injectors. Did you clean and check these? Anyway, the regulator doesn't sound so good.
Was thinking stuck injector too but several of them, both banks? Forgot to ask no check engine lights? They light up when the system is energized but not running to make sure they work?
Good point, but I wouldn't completely rule them out. When I had my rattling gearbox issue, my tech found one unrepairable injector and one clogged one. These cars don't like sitting around for long periods.
I think they are the 3.8bar version, but I'll take the left one out on the table before buying anything. Yes, but it shouldn't warm that much that fast . We changed the relay and the new one feels much more normal. No, not yet - but good point to check them. Euro car, no CELs. Though I might install them, especially after experiencing this
The Injection and Fuel Pump relays (4 in total, Bosch 0 332 014 140 or 0 332 019 140) are special because they have lower resistance solenoid coils (65 Ohm) as compared to ~90 Ohm of the other relays on the panel and of what most car cube relays have. Because of lower resistance coils, the Injection and Fuel Pump relays will draw higher current (when holding) and heat-up more than all other relays on the panel. This is normal. You should compare the numbers of the two Injection relays that you originally had, the "not so hot" one and the "hot" one. Perhaps your "hot" relay is original and the other, that was not heating-up as much, was a normal relay used as a replacement of the original one.
Yes, there are 2 types of FPR for the Ferrari 348: - 137960 (Ferrari ref.) / 0280160731 (Bosch ref.) Valid for the early model. 3.0 bar. - 147281 (Ferrari ref.) / 0280160738 (Bosch ref.). Valid for the later model. 3.8 bar.
The broken FPR has Bosch number 0280 160 715. The fuel line from the pump is with threaded connection, the return line is not. Pic attached. Now I think it's the 3.0bar version. Ahh, thank you for this! I'll compare the relays. Image Unavailable, Please Login
I called Finjector (who specialises in fuel delivery) and they regocnized the part number as 3.8bar. I did find a thread also from the return line also, it was just a bit hidden as the installation foot is screwed on there. Finjector guys are now checking if they can offer me a solution from a more generic parts. If they can deliver from shelf, I might get forward on this tomorrow.
Are they sure it's a 3.8 bar? https://www.ferrarichat.com/forum/posts/147354788/ If the 715 is the same as the Volvo 1306965, then there is one here: https://www.skandix.de/en/spare-parts/engine/fuel-mixture-formation/injection-system/injection-pump/fuel-pressure-regulator/1070239/
Damn, that's interesting. They checked the specs from computer and after all it's always possible that the computer has wrong information, but should be quite rare on Bosch parts. But if people here have actually replaced 0280 160 715 with the 3bar PR161, it eases my search up quite much.
There are a bunch of reasonably priced alternate choices for the 3.0bar FPR available in Europe, which should be interchangeable. Even though, as the PR161 has apparently been tested by multiple Fchatters to be functionally, physically and visually practically identical to the original, I decided to play it safe and order the PR161 from Rockauto. As estimated, the part was delivered today. My workday got a bit long, but after a bit over 10,5h of working I got a 20min break, during which I installed the new FPR. Around half an hour later, I got another break and went to test the car. It started ok and idled quite nicely. Gave a bit of a throttle and got a shot in the exhaust again. I raised the candles to daylight and considering from them, the left bank seems to be running quite ok. There's proper signs of burning, but no extent amount of soot. On the right side, the plugs are quite black of soot. So the left bank seems ok now, the right bank is running rich. Either there's something else, or I'll end up saying that stupidity gets rewarded as I didn't order 2 FPR's at the same time. I'll probably continue investigating this on Saturday. Thanks for the help so far! EDIT: Can someone point where the ground points 150A and 150B are? The ground of right side MAF seems to be floating a bit (just a bit, but this also might affect the mass air measurement and will be problem at least on the long run) and I'd like to check the ground points of both sides.
I believe they are on the backs of the cylinder heads (bumper end). Not sure which is which, so clean both on each bank. I don't have a pic of the 348 ones, but here are the grounds on the back of the 355 (earlier cars) https://www.ferrarichat.com/forum/posts/145935799/ There will be other grounds connecting the engine to the chassis. There are specs for ground resistance. I think 0.2 ohms.
Ooops.. My mistake. Is that the same for the 2.5? I can't see the grounds for the 2.5 in the parts manual.
Just on principle, while the engine is running check the vacuum line on the top of the FPR for raw fuel leaking. This would be sucked directly into the intake manifold if leaking. Had s similar problem once.
And if your valve cover is painted like Miro's, make sure the paint at the ground points is all sanded off to expose the metal for a clean connection.
You can verify timing of that engine in situ. You need to use scope and in cylinder pressure transducer. Then check servicemanual data when should exhaust and intake valves open and close. Basic diag stuff.
