Hi all, I have a 1985 Mondial QV cabriolet (Euro version). I've owned the car for a few years now and have been slowly replacing aging components. More recent replacements include the ignition leads, spark plugs, coils, rotors, fuel pump and starter. I've also had the alternator refurbished and have installed the WR1 hot start relay. About a year ago, I sent off my fuel distributor and regulator and had both serviced by CIS Flowtech. At the same time, I replaced all the fuel injectors. A couple of weeks ago I was taking the car for a short drive and it suddenly stalled. I was able to briefly restart it before it stalled again. I was able to turn over the engine without any issue, but it seemed as though the engine just wouldn't catch. With help, I was able to push it back to my garage and start troubleshooting. I had good power to the coils, the coils were in good shape and I was getting spark at all plugs. There was good gas pressure. I read a couple of threads here where people seemed to suggest a possible issue might be with dirty ignition switch contacts. So, I took my switch apart, cleaned all contacts and put things back together again. I turned the key and the engine fired and ran, for about 30 seconds before the rpms dropped considerably and then the engine stalled. It was at this time I noticed that my tach was no longer providing any reading. I tried to restart the engine and while it would turn over easily, it wouldn't start. Today I checked all fuses - they are all good. I also checked the relays - they all seemed fine for continuity. However, I noticed something odd when I took out the start-up fuel pump relay to test it: Terminals 30 and 87a are connected - and this is how it should work. With no power, I verified that terminals 30 and 87 are NOT connected - which again seems to make sense to me. As I understand it, the connection between 30 and 87 only occurs when the relay is energized/powered. BUT - with the battery disconnected, when I plug the relay into the fuse panel, there IS a connection between 30 and 87. If I connect the battery and try to start the car, the ohmmeter initially shows some resistance between 30 and 87, before showing that the circuit is completely open. What I'd like to know is - does this mean I likely have a short on the fuse panel itself or perhaps the fuel pump? Or is there maybe some other explanation? Thanks!
This is normal. There's a bunch of other things in your car that are connected to terminal 30 and terminal 87 of that relay. You would have to unplug a whole bunch of other stuff (e.g., the CSI, the TTS, and the fuel pump relay) to get an infinite Ohms resistance measurement between terminal 30 and terminal 87 of that relay when plugged in. Measuring the resistance of a circuit with a DMM with a voltage applied is probably not valid. Have you removed the fuel pump relay and installed a jumper wire from the female metal terminal 30 in the fuel pump relay socket to the female metal terminal 87 in the fuel pump relay socket just to confirm that the fuel pump works? (The fuel pump should run, even with the key "off", with the jumper in place.) Image Unavailable, Please Login
Steve, Are you referring to the start-up fuel pump socket - (relay (i) in the attached image) or the fuel pump socket (relay t). I have just tried attaching the jump wire to the start-up fuel pump socket as you indicated and then reconnected my negative battery cable, but there's no sound coming from the fuel pump. Image Unavailable, Please Login
With the jumper wire installed as you noted in the fuel pump socket (relay t) and with the battery connected and the key off, the fuel pump runs.
You can try starting the car in that condition: If it does start and run with the jumper, but won't with the fuel pump relay t in place = you'll need to look into why (we'll go here if necessary -- let me know). If it still doesn't start = probably an ignition problem. Have you checked for spark during starter motor cranking with a timing light or spark tester?
With the jumper wire installed, the car does not start. I have just rechecked for spark during cranking using a timing light. There is spark at all 8 spark plug wires.
That's trouble. With the fuel pump running and spark present, but it won't start, you're up to the next level of diagnosis difficulty on a euro K-Jet without Lambda (as it has nothing else electrical to go wrong if stock) = measuring the regulated supply fuel pressure and the cold and warm WUR control pressures, confirming the CSI does squirt for a second (or two) during the first initial cranking attempt after the overnight, etc.. Or has the car been modified for US importation (by adding a FV and an aftermarket ECU to provide quasi-Lambda functionality)? Can you post a picture of the engine bay?
I believe the engine is stock (but happy to have your opinion). Attached are photos of the engine bay. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Here's a silly question - is the timing light only measuring whether or not there is sufficient current going to the spark plug? Or is it also determining whether or not the spark plug is actually firing? I ask because I just thought I would go and check the spark plugs themselves and all of them are black, making me wonder if there is in fact spark occurring.
Don't think that that's a sensor. I believe it's just the (stock) air line going to the later (engine 517 and after) AAV mounted to the coolant overflow tank (and maybe someone has "updated" it to an AN fitting to use a braided stainless-covered air line). Stock fitting 13 and hose 72 here: https://www.ferrariparts.co.uk/diagram/ferrari/mondial-qv-coupe-cabriolet/011-fuel-injection-system-fuel-distributors--line
Certainly no harm in trying a fresh set of spark plugs if you think that they are all fouled (and they'd need to be replaced anyway if they are fouled). However, if that solves your issue, the fix may be temporary as something caused the fouling (running excessively rich).
There is no sensor there. I'm guessing a previous owner may have added that. It's actually capped off with the blue nut - perhaps for future use if required/necessary. Here's a clearer image of that area... Image Unavailable, Please Login
Ok, so I have brand new spark plugs here already. Tomorrow I will install them and see what happens. I will also run through the fuel pressure checks as mentioned in post #10 and report back.
Alright - so I've checked the old spark plugs for spark (via connection to ground) and they are sparking. Even so, I replaced them all with new ones and tried starting the engine with no luck. I had checked for air/vacuum leaks a couple of months ago and didn't find any. But since some of the hoses were old I replaced them at that time anyway and rechecked to make sure there were no leaks. I just tried doing a fuel pressure test: - pressure gauge connected between 14mm fitting on WUR and the top centre hose on the fuel distributor - blue safety switch on fuel distributor disconnected - WUR & cold start valve disconnected Cranking the engine produced no pressure reading. I also tried installing the jumper wire in the fuel pump relay socket (as referenced in post #7) & reconnected the battery and still no fuel pressure reading. Keeping in mind that my WUR and fuel distributor were serviced by CIS Flowtech less than two years ago, I'm wondering about the best order to follow to go through fuel system checks. Is the next best step to disconnect the fuel pump output hose and check for flow with the pump running? Then, if all seems good there do I check for flow at the fuel filter output perhaps?
The best functional test is to measure the fuel flow in the return line from the fuel distributor pressure regulator going back to the tank -- see pages D33 and D34 of the 281/83 Mondial8/QV WSM.
Your "no pressure" measurement is a fatal flaw, but it's a little strange that the pump would "sound" normal when running and do nothing -- but, at least, you've found something that needs to be fixed/corrected for sure. You can then move upstream from there (to see if you can find a blockage somewhere), but the bottom line is that you need the specified pressure and the minimum return flow volume rate.
Just a note from a very similar problem I had on an engine with K-Jetronic (1978, no cats) : Car sits for 6 months every winter. Normally starts right away, but after the previous winter it didn't. Same sympthoms as yours Crank: Check Spark: Check Pump: vibrated, hence: Check still no start More than once I started to disconnect the fuel lead from the pump to the K-Jet distributer, but when unfastening, fuel started dripping lightly so I re-fastened thinking that would indicate sufficient supply to start. I then used (I hate to do that) Starter-Spray: and yep, it would run straight away but only for as long as I'd spray it. >>> It HAD to be a fuel supply issue. I then completely disconnected the fuel supply line from the K-jet and hung it in a bottle. Cranked it: NO FUEL but a few drops OK, I then took out all spark plugs to allow the engine more revs when cranking: First still nothing, but then I decided to manually push down that air-meter plate, pretending full-throttle. After a short moment and with a "Blob" fuel shot out filling the bottle in no time. Reconnected everything: Car started right away and ran happily all of this summer. In my case it seems to have been a clog in the fuel supply line, probably thanks to the mandatory E5 ****ty Eco-fuel we have to fill up with here in Europe. If it didn't help, at least it was a nice story.... ; ) Mondi Cab
