Weird starting problem


#1

Car starts normal when cold, but when hot or warm it turns over when the key is in the cranking position but doesn’t start until you release the key to the run position.


#2

I suggest telling us what make model and year car you have.

My guess is a relay.


#3

When the key is in the crank position, the starter motor, ignition and fuel injection (if a modern vehicle) are activated. All the other electrical load is off. It is possible that when the car is warm, either the ignition or the fuel injection is not being fed power while the engine is cranking over. When you release the key, there is enough momentum that the engine turns over enough to start.


#4

I am sorry about that, I should have described the car. It is not modern car, strictly a nuts and bolt car with no features.
It is a 1980 Citroen 2cv, 602ccm 2Cyl 29hp air cooled engine with electronic ignition.


#5

What a car! I still think that the car isn’t getting ignition when the key is in the crank position. You might try turning the key to run (not start) and try push starting the car or rolling it down a grade and letting out the clutch (I assume with 29 hp that it isn’t an automatic). If it starts instantly, you probably have the problem I described in an earlier post. Alternatively, have someone test for spark as the engine is being cranked in the start position.


#6

First of all thanks for trying to help. I have had the car in the hands of 2 different mechanics. And after they get done with all their testing, they admit they don’t know what to do about the problem. Some things have been done to try and fix this weird problem, but nothing that was done really fixed the problem. It is only this way when the car is warm or hot.
I have made inquiries to the Citroen clubs in France & Germany, and basically (if I translated correctly) they said they never heard of such a thing. I guess I should feel honored! This car (2cv)was in production for 50 years in various countries of Europe and South America. Over 5 million of these cars were manufactured, and it sounds like I am the only one with this problem.


#7

I assume that the mechanics that examined your 2 CV checked for spark while the key was in the “start” position and the engine was cranking. This would be the first step. In the things that have been done, was the ignition switch changed?

Starting and running are two different functions. The 2 CV isn’t that complicated. Maybe you should try another mechanic.


#8

The ignition switch was replaced, a new battery was installed, the valves were adjusted, and the starter wires were removed, & terminals cleaned.
As far as the mechanic checking the spark when the engine is cranking, I don’t know.
I will have to ask him tomorrow


#9

Let’s start attacking the problem methodically. Get the car hot, then have a friend crank it while you follow Triedaq’s advice and check for spark. Assuming you have spark, check for fuel delivery (the easiest way is to see if fuel is getting into the carb). If you have both, then it’s probably either a timing problem, or a choke problem - i.e. it’s throwing too much fuel in there for a hot engine, and so it can’t ignite the mix.

One problem with modern mechanics is that a lot of them have gotten spoiled by OBDII engine diagnostics to the point that if they don’t have a computer telling them what’s wrong, they just hurl parts at the problem and hope something fixes it. No diagnostic skills. That could be the problem you’re running into with the mechanics you’ve brought it to - - that and your car is somewhat of an oddball these days, especially on this side of the Atlantic, and there aren’t many people with experience working on one.


#10

This message is for shadowfax. I THINK YOU ARE ON TO SOMETHING. In the past flooding has been a problem. The carb was supposedly rebuilt. But what did happened (at times), was if it didn’t start on the first crank it flooded, when hot or cold. After sitting awhile, it would start. If its an adjustment on the outside of the carb, its a mystery, as there is only one screw for an adjustment. So probably its something inside the carb, but I have no idea what that could be, and it seems no one else does either.