Technical Trouble starting

[tobywood13]

Hi all, I have a 1992 Panda CLX with the FIRE engine. A few days ago my car had a hot start issue which I solved by pouring cool water on the fuel lines, the next day it took a lot of cranking to get the car going but then it was fine all day, now it won’t start properly.

With no choke and the throttle held all the way down it will run for a few seconds, rev with the throttle, but then splutter and die. When it dies the carb seems quite full with fuel. I’ve replaced the vacuum diaphragm, taken the carb apart and cleaned it, changed the in-line fuel filter (which doesn’t fill up very much now), and still it won’t go. I also ran the fuel pump into a bucket as I cranked the car and it delivered fuel in bursts or pulses rather than a steady flow. Any ideas what might be wrong still? I’m thinking the fuel pump, but as it’s mechanical and it ran fine after a rough start the other day I’m not certain. Thanks!

 

[Mattwyse]

? Starter motor. Often don't work when hot but start fine when cold.

 

[tobywood13]

? Starter motor. Often don't work when hot but start fine when cold.

This happens when the engine is cool though, besides the weather being warmer. And the engine does start for a few seconds but then dies off.

 

[tobywood13]

The overflow chamber after running for a few seconds fills up with petrol, covering the main jet and then the engine stalls.

 

[Dragon Man]

does sound like a float issue in the carb. i have had it myself. you can take the carb apart carefully to not damage any seals and bend the little metal tag the float needle valve sits on upwards a bit. this will make it shut off more sooner and stop the over fuelling issue.

 

[tobywood13]

does sound like a float issue in the carb. i have had it myself. you can take the carb apart carefully to not damage any seals and bend the little metal tag the float needle valve sits on upwards a bit. this will make it shut off more sooner and stop the over fuelling issue.

Yesterday I adjusted the float level and replaced the needle and seat, then it started and ran fine. Now, it’s not starting again, so I don’t know if my adjustment did anything or if it started just because it had sat for a few days.

It isn’t overflowing now, but it just barely runs for a few seconds, and you can count the individual ignitions as it does. Putt-putt-putt-putt. Then it dies. It won’t start with any choke applied, and runs for longer with the throttle held down.

The carb isn’t flooding, so now perhaps it’s being under fuelled? I’ve adjusted the needle height on the float again and still no different. There is petrol in the float bowl too.

 

[jackwhoo]

Ignition contact breaker or electronic?

 

[Dragon Man]

hmm at 1992 it should be electronic. I'd replace the ignition module... if its intermittently firing my go too is ignition.
if its the older style i would replace the points and capacitor/condenser.

 

[tobywood13]

hmm at 1992 it should be electronic. I'd replace the ignition module... if its intermittently firing my go too is ignition.
if its the older style i would replace the points and capacitor/condenser.

Latest update, switched to a larger battery from my other car and it did start, but was very rough. Throttle had to be held open while cranking to get beyond the putt putt putt stage and then it crawled itself up to a rough idle with bits of throttle applied here and there to keep it from stalling, it sounded almost like a lawnmower being started from a sedate tug on the pullcord. Low RPM, choke on or off made no difference strangely. When it warmed up it ran perfectly fine and revved well after some fiddling with mixture and idle, but while it was warming it was very hesitant to rev, almost stalling when full throttle was applied suddenly. As the battery appeared to make a difference, does this suggest something ignition related? The other battery was cranking fine, not showing any symptoms of running low. Perhaps the battery was just a coincidence of when it decided to run after an hour or two of fiddling and cranking with no signs of a start beyond a putt putt putt.

I'm just confused why it won't start despite apparently having fuel, air, and spark, but then suddenly it will. And when it does start it's very unhappy but then clears right up and appears perfectly fine when it's warm. Thanks for the help so far chaps.

 

[Dragon Man]

hmm next time its acting up, try installing a jump lead from the engine to the body. or body to battery negative. see if that makes things change. interesting how things changed when you replaced the battery. pandas and cinquecentos are well known for having the mid connection point on the main battery earth cable failing.

 

[jackwhoo]

The symptoms are those of a weak spark.
Decades ago I spent many hours trying to fix a carb problem only to find it was weak spark .......I'm not the only one......

 

[tobywood13]

The symptoms are those of a weak spark.
Decades ago I spent many hours trying to fix a carb problem only to find it was weak spark .......I'm not the only one......

What’s the most likely cause of a weak spark? Distributor timing? Or a failed component?

I’ve never had to adjust a distributor before and electrical stuff always confuses me! Thanks.

 

[jackwhoo]

Ignition contact breaker or electronic?

 

[tobywood13]

hmm next time its acting up, try installing a jump lead from the engine to the body. or body to battery negative. see if that makes things change. interesting how things changed when you replaced the battery. pandas and cinquecentos are well known for having the mid connection point on the main battery earth cable failing.

I’ve got the big battery hooked up for the first start attempt this morning, tried jumper lead between body and engine, negative post and body. It’s still just chugging along with throttle held open for a few seconds before dying, so the battery doesn’t seem to have made any difference after all.

 

[tobywood13]

Pretty sure it’s the old style points system.

 

[jackwhoo]

Post pictures of distributor and ignition coil
Have you checked the spark plugs gap?

 

[jackwhoo]

Checked distributor cap for cleanliness?
Carbon contact on spring in centre of cap still there? And gently springy if gently pressed?
Rotor arm look burnt? Brass bit in centre is touched by the carbon contact in cap, clean the brass bit with a green scouring pad(The brass can tarnish badly affecting spark)

 

[tobywood13]

Checked distributor cap for cleanliness?
Carbon contact on spring in centre of cap still there? And gently springy if gently pressed?
Rotor arm look burnt? Brass bit in centre is touched by the carbon contact in cap, clean the brass bit with a green scouring pad(The brass can tarnish badly affecting spark)

My spark plug socket is too big so I’m waiting on a replacement to check the plugs. The distributor looks pretty grimy on the outside, I’ll try and get inside it and hopefully not mess anything up. Previous owner had the distributor and the ignition coil all wrapped up in plastic so maybe this was a regular fault…

 

[tobywood13]

Here’s the rotor, inside the distributor, and the cap. A little dirty perhaps? But it does eventually get running, although so far not today.

 

[tobywood13]

I put a new spark plug in each lead, only one cylinder fired (the rightmost one when looking into the engine bay). Each spark lead produced a spark when put in that cylinder’s position. So if only one plug is receiving a spark, what is causing this? I cleaned each position in the distributor cap, didn’t appear to make a change. Can an ignition coil only produce one spark, but then start working normally when the car gets going?