Hey everyone, 1981 M8 Euro. After replacing a dead fuel pump, fuel filter and sealing a hole in the port side gas tank, I was able to get the Mondi to fire! Problem is it dies right after. It will run and stay running if I keep spraying starter fluid into the fuel/air meter under the air filter. I have also hardwired the fuel pump to the battery, for troubleshooting purposes eliminate any electrical voodoo and it still just dies after 1 to 2 seconds. There is good fuel pressure all the way to the inlet of fuel distributor. Any ideas? Here is a video (albeit a crappy one) so you can sorta hear it for yourself. Not my garage in this video I might add. This place is way too cluttered for my taste... https://www.youtube.com/watch?v=3IitlPQM2w4
I assume you aren't getting a fuel smell after you try to start it, so it is a delivery problem. My first guess would have been the fuel pump was put in incorrectly (I have reversed it once myself in a 911), but if you are getting good fuel pressure going the right direction then that wouldn't explain it. Is it possible there is a clog in the system from the distributor forward?
I'll bet your fuel injectors are clogged. They should spray fuel like this: https://www.youtube.com/watch?v=rSLcEwdX3ns
The pump is right for sure. I was thinking it might be a gummed up fuel distributor. It did sit, forgotten about for over a decade. I'll have a look at the injectors too. I just wonder if I should be looking for something electrical before digging into the jetronic. Taking that thing apart seems like something that should be taken pretty seriously.
If it was electrical, she wouldn't be running with the starting fluid. So that's a real good test. If you think the distributor is not working, you can just pull the injector pipes, and test. Start with the rear bank, which is easier to remove. Put containers under the pipes to catch the fuel. Turn the ignition switch to the run position. Then push down on the air vane. Fuel should flow out of the pipes. If fuel is flowing good out of the pipes, pull the injectors and hook them up to the pipes and test. You only need 12mm & 14mm wrenches to remove the injector pipes. This is a neat tool you can make to pull the injectors: https://www.youtube.com/watch?v=d2GtwBuXWMc
Brian Congrats it started over! IMO you should read up on the FI system and do some searches in the 308 section for 2V starting issues Ive found that simple Google searches pops up Fchat threads to read
While firing up another Mondial 8 engine, we found out that the pinion inside the K-Jetronic was stuck, so we dismantled the Jetronic and made sure the pinion goes up and adown again smoothly. We got it loose by using compressed air. Check this too. Image Unavailable, Please Login Image Unavailable, Please Login
I believe they call that part the "control plunger". If it were stuck, you wouldn't be able to move the air vane. So you might want to try and move that air vane first, with the fuel pump turned off, in order to make sure that control plunger is not stuck. It should move smoothly all the way down. You can see a technician in this video moving the air vane to test the injectors. The further down the air vane is moved, the more fuel pressure is applied to the injectors. https://www.youtube.com/watch?v=1-PuxKL3ieY
with the plunjer stuck in the upper side of his cilinder, the air vane moves free without hesitation. The only way to get it free is with air pression in to the hole in the middle of the distributror. Guido
That's true. But if the plunger was stuck due to lack of use, I would think it would be stuck at the idle position, not at WOT. Also, if it was stuck all the way up, I would think the engine would be flooded, and not start. In proper operation, there should be some resistance at the air vane, if the fuel pump has been energized. You are pressing against the fuel pressure. Once the plunger is pressed all the way up (air vane all the way down), the air vane does move easily. However, once the fuel pump is energized again, there should be some resistance at the air vane again. But you are right, the plunger could be stuck in the upper position, or in any position for that matter. Just check for proper operation.
These are all great suggestions. One thing I will have to check first is the return pressure fuel line. I don't think there is any return flow back to the tank when the fuel pump is on. My guess is that with 10 years of old gas sitting in the FD and injectors, there is something getting blocked. Whatever the issue turns out to be, I will make sure I post the resolution for the next person that runs into these symptoms.
OK everyone, I have pulled all the injectors and not a single one would spray any fuel. I tapped them lightly and pushed 50 psi of air through them until they worked. I think the cold start injection was why it would only run for a few seconds. Now I have so much fuel in the cylinders, it's leaking out of a hole in the muffler! Needless to say I didn't keep turning it over as soon as I saw that. Do you guys think the problem now would be what stekkefun4 mentioned above? If we all think that is it I'll pull the FD and check that control plunger. When I first got it I couldn't push the air flow meter down (under the air filter) I pushed a few more times and it popped down but now there is no resistance if that could be another indicator of a stuck control piston.
You should check out my injector test jig: http://www.ferrarichat.com/forum/mondial/531214-cheap-quick-cis-injector-cleaning-tester.html But yeah, it does sound like the plunger in the FD is getting stuck. When the fuel evaporates out, it leaves behind a sticky varnish. You can try disassembly and cleaning. The fuel should act as a lubricant when it's working. Also, don't start the car with a cylinder full of fuel. That could blow a hole in a piston. Leaky injectors have been known to cause this as well. And you may need to change the oil, if it has been contaminated with fuel.
IT RUNS!!! Well everyone, it fired up today and ran like a Swiss watch. After 15 or so years it's back from the dead. The final puzzle piece was in fact a stuck metering plunger. Once I was able to get all injectors to squirt (all 8 were clogged solid) The stuck metering plunger was allowing fuel to just pour in and that flooded the engine as soon as I turned the key, the engine had no chance to start or even fire one cylinder. I pulled the fuel distributor off and sure enough that plunger was all the way up or open. By holding the unit so that gravity would pull down on the plunger I was able to tap the unit until it moved a little and then slowly pull it out. Taking off the nut and the retaining ring took special care to remember exactly how it went on. Once I cleaned it all out with some alcohol astringent that I use on my face (Sea Breeze) everything when back together beautifully. I used a little WD-40 to make it go back together nice and smooth. so to recap here is what it took: - remove outlet hose and internal filter from fuel tank and clean - replace fuel pump - replace fuel filter - pull fuel distributor after removing all lines and three straight slot screws. - remove, clean and refit metering plunger (this job is easy don't let the internet scare you) - remove each injector and test with compressed air. Tapped each one until it sprayed. So really, the entire fuel system needed attention after sitting this long. I couldn't have done it without all of you. Being this was my first run in with the K-Jetronic, it was a great experience! Here is a video that explains exactly how this system works. It really helped me troubleshoot what was going on. https://www.youtube.com/watch?v=a4fJAfXYxWk Thanks again everyone.
Congratulations ! Love that WD-40 magic in action ! Make sure you fire her up once a week for exercise. Ferraris hate to be left alone.
I have suggestion to add eight ounces of 2cycl out board motor oil to each tank of gas. I have been doing this for years. Lately I have been using Marvel Mystery Oil which I think is just kerosene. The idea being to coat every last surface with a thin film of oil. Its a more common practice then you might suspect. Try a google search on the subject.
