mondial non hot start problem

just bought a 2nd 1984 Mondial 3 QV and during recomissioning found a couple of faults,. Cold start is A1, starts first and every time, drives great, after been running a few miles and gets good and hot, its a complete s**t to start, if it ever does, it cranks over all day until the battery flattens, no fuel smell, just spins round, leave a while until its cold, then it fires up first time again and runs fine.
So it s not the usual battery voltage dropand its not the starter this time,
any thoughts??
thanks
js

 

Join the club. The fuse block has a problem. The best thing to do is is by pass the fuse block. Do a search for fuel pump bypass.

It will take you about 30 minutes to re-route the fuel pump relay.
Good Luck

Charles

 

thanks Charles, any diagrams or help topics of past to guide me to the right sector?
js

 

It could also be the solenoid on the starter, very common. Cheap part do a search on "ace solenoids" I bought one for 20 bux.
OOps just read more carefully where you rule out the starter...yeah its the fuse block, thats the ticket!

 

When you have the hot restart problem (i.e., starter cranks over OK but engine never fires):

1. Unplug the safety switch on the airflow meter and turn the key "on" (Pos II) -- confirm that you can hear the fuel pump running (this pre-presuurizes the fuel system).

2. If the fuel pump does run, turn the key to Pos III (start) and see if it will start.

If you fail test 1 -- electrical problem with fuel pump/fuse block stuff.

If you pass test 1 but not test 2 -- put a timing light on it to confirm/deny the presence of ignition.

If you pass both test 1 and test 2 -- most likely the check valve on the fuel pump (outlet) or accumulator is kaputt, but could be a fuel pump electrical problem too (when the safety switch is closed, the FP gets it's power during starter motor cranking via a different path).

Post which results you get for tests 1 & 2.
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I put my money on the accumulator.

 

many thanks guys, away a few days, will test it end of week and see what results, will post
thanks
js

 

ok, has acouiple of hours today, so removed the air filter, disconnected the safety switch, turned key to pos1 and I can hear the fuel pump humming continously,( doesnt stop unless I switch off), turned the key to Pos2 and it started!!, re connected the switch, turned the key to Pos 1 but could not hear any pump noise at all, again the engine fired up on Pos 2, after a good run of miles, many stops and starts, it seems to have self cured which is really worrying as it will self inflict later>>>
any thoughts from Modial gurus?

 

So do I. The Accumulator was the problem with mine.

 

I'm a little surprised that you guys are reporting so much operational trouble with the accumulator -- usually these get replaced because they are leaking fuel externally, rather than not holding the pressure up at shutoff (but I guess that's possible too).

John -- What you reported is normal (but let's agree on the key positions -- pos 1 = off, pos 2 = "on", pos 3 = start) -- with the safety switch plugged in, the fuel pump will not run with the key in pos 2 unless the engine is actually running -- i.e., unless the airflow metering plate significantly deflected. But can you clarify your report -- were you actually having the hot restart trouble before you removed the air cleaner...etc.? Another point is that an immediate hot restart isn't really the most difficult situation (although please clarify if this was the prior problem). If the fuel pressure is dropping abnormally low after shutoff, restarting after 15~30 minutes would be the most difficult situation (the fuel in the system-- now at low pressure -- has had time to absorb heat and vaporize, but the engine is still warm enough that the cold start injector will not fire during restarting). The check valve on the fuel pump outlet is a ball that is spring-loaded into a conical seat so a little debris shifting around can cause variability in how well it seals. Give a shout if you get any bad symptoms coming back