car will crank, but not start
#1
![Default](/forum/images/icons/icon1.gif)
Problem: starting the cold car and moving and a few yards - after this the engine will not start.
I am no technician and this thread is meant only to share experience for those running into a similar problem.
We bought a XJ 8 with 60.000 on the clock in mint condition a year ago, with the intention to keep that.
It was giving no problem at all, indeed running smoothly until I backed up on the parking place to give room - after this it would not start the next day.
As usual, when something unexpected happens, we thought the worst case and made the first mistake not to look into the drivers handbook. If he would we would have found the following advice: put the pedal to the floor and crank the engine, then ease it back to see if it will start, it may be flooded if started and shut off in cold condition.
As said, we believed the worst and I went into Internet (to be pleased to find this forum).
Evaluating the situation in a calm mood, the car has not given any indication of any problem otherwise. Trying to start the engine the sound was so faint, that I had my daughter to do this and check actually that the belt was moving - so the starter was working and the engine was turning.
Not necessarily, but with a good guess one could rule out mechanical problems, that leaves ignition and fuel. There was a faint smell of fuel in the back.
Unfortunately, the days before I had some smell of electric in the car (which coincidentally may have come from the outside - these are the funny tricks, life is playing). It set me on the track of the fuelpump, which may be easier to check in the first place. So I paid attention to the sounds when switching on ignition, and I decided what could be heard should be the fuel pump. Leaves ignition, and since I do not know the type of spark plug actually in the engine (and if changed before) I consider this as one thing to do.
I researched the Internet and found a lot of advice, especially in this forum. That a Jaguar with all that electronic could be flooded was out of my score of understanding - but it was the simplest case to believe in taking into consideration that there have been no other indications of any malfunction.
Reading all the posts about cylinder wall washing and bad compression confused me at first. The idea of injecting oil into the engine I sorted into a last resort, especially as this does no good to the catalysator. The methods discussed veried and where partly not quite clear on the precise procedure (for example, not to kill the starter motor).
In the end I distilled this procedure for me, which was successful:
Fully charge the battery, on the first attempt mine died halfway.
Put down the pedal and keep it there. This will shut off the fuel. Somewhere it said to start the engine for 2 minutes at 30's second intervals.
I do believe for drying the engine at keeping the conditions (that means, keeping that foot on the pedal) it should make no difference apart for the starter motor and the battery to cut the starting attempts down to 10 to 15 seconds intervals, then of course double the amount, approximately eight to 10 times.
After this - still keeping the pedal down all the time - I ease it off approximately half way. Now you have to listen and feel closely: when starting, does the wine of the starter motor go down in the same way the battery gets empty? I had a feeling after a few cranks, that the whine was somewhat stabilising, meaning, that the starter motor is relieved of part of the load, which can only be if some cylinders are firing.
Be aware, that the engine may not gladly start up but will work its way back into live again. Consequently the sound of the starter picked up speed instead of dropping and as in this way the load on the starter was removed I left it running - and actually the engine with occasional very light shudders was back into live again.
Doing this the first time you may have difficulties to distinguish when to cut off the starter motor (due to the engine being able to run for itself). This is owned to the fact of the good sound isolation.
Point is, if you relieve the starter motor and the engine will not run you may have to start all over, meaning to charge the battery first.
Okay, I got this cat running again.
There is a joke, that goes:
a student of medicine in an examination is asked what is the case with a lady complaining about being sick.
The student explains all the common and not heard of diseases he can think of. Nothing fits.
The final question of the Professor is: how about being pregnant?
I am no technician and this thread is meant only to share experience for those running into a similar problem.
We bought a XJ 8 with 60.000 on the clock in mint condition a year ago, with the intention to keep that.
It was giving no problem at all, indeed running smoothly until I backed up on the parking place to give room - after this it would not start the next day.
As usual, when something unexpected happens, we thought the worst case and made the first mistake not to look into the drivers handbook. If he would we would have found the following advice: put the pedal to the floor and crank the engine, then ease it back to see if it will start, it may be flooded if started and shut off in cold condition.
As said, we believed the worst and I went into Internet (to be pleased to find this forum).
Evaluating the situation in a calm mood, the car has not given any indication of any problem otherwise. Trying to start the engine the sound was so faint, that I had my daughter to do this and check actually that the belt was moving - so the starter was working and the engine was turning.
Not necessarily, but with a good guess one could rule out mechanical problems, that leaves ignition and fuel. There was a faint smell of fuel in the back.
Unfortunately, the days before I had some smell of electric in the car (which coincidentally may have come from the outside - these are the funny tricks, life is playing). It set me on the track of the fuelpump, which may be easier to check in the first place. So I paid attention to the sounds when switching on ignition, and I decided what could be heard should be the fuel pump. Leaves ignition, and since I do not know the type of spark plug actually in the engine (and if changed before) I consider this as one thing to do.
I researched the Internet and found a lot of advice, especially in this forum. That a Jaguar with all that electronic could be flooded was out of my score of understanding - but it was the simplest case to believe in taking into consideration that there have been no other indications of any malfunction.
Reading all the posts about cylinder wall washing and bad compression confused me at first. The idea of injecting oil into the engine I sorted into a last resort, especially as this does no good to the catalysator. The methods discussed veried and where partly not quite clear on the precise procedure (for example, not to kill the starter motor).
In the end I distilled this procedure for me, which was successful:
Fully charge the battery, on the first attempt mine died halfway.
Put down the pedal and keep it there. This will shut off the fuel. Somewhere it said to start the engine for 2 minutes at 30's second intervals.
I do believe for drying the engine at keeping the conditions (that means, keeping that foot on the pedal) it should make no difference apart for the starter motor and the battery to cut the starting attempts down to 10 to 15 seconds intervals, then of course double the amount, approximately eight to 10 times.
After this - still keeping the pedal down all the time - I ease it off approximately half way. Now you have to listen and feel closely: when starting, does the wine of the starter motor go down in the same way the battery gets empty? I had a feeling after a few cranks, that the whine was somewhat stabilising, meaning, that the starter motor is relieved of part of the load, which can only be if some cylinders are firing.
Be aware, that the engine may not gladly start up but will work its way back into live again. Consequently the sound of the starter picked up speed instead of dropping and as in this way the load on the starter was removed I left it running - and actually the engine with occasional very light shudders was back into live again.
Doing this the first time you may have difficulties to distinguish when to cut off the starter motor (due to the engine being able to run for itself). This is owned to the fact of the good sound isolation.
Point is, if you relieve the starter motor and the engine will not run you may have to start all over, meaning to charge the battery first.
Okay, I got this cat running again.
There is a joke, that goes:
a student of medicine in an examination is asked what is the case with a lady complaining about being sick.
The student explains all the common and not heard of diseases he can think of. Nothing fits.
The final question of the Professor is: how about being pregnant?
![Icon Doh](https://www.jaguarforums.com/forum/images/smilies/icon_doh.gif)
#4
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As stated, I am not an engineer or technician. Still I thought a little about what happened to me.
Provided, there has been no obvious sign of any difficulty with the engine. That means, ruling out mechanical problems other than deterioration by wear.
On modern engines with electronic management of ignition you might rule out that there is a problem with the drop of the voltage due to the starter motor. That leaves two options on an engine not starting up: fuel and ignition.
Although it cannot be ruled out: if the engine had been running before now why should suddenly all of the ignition fail? its most improbable. On an engine with a lot of cylinders a failure of all of the spark plugs can be ruled out - a failure would be in one or two spark plugs, resulting in an sputtering engine.
What is in continuous change is the supply of fuel. So here I would expect the reason for a problem (with electronic ignition management).
Now provided, the fuel supply is available. Take a close look to the conditions in the engine:
The engine is cold, this meaning, the pistons are not yet expanded by heat and thus give more room to the cylinder walls, meaning less sealing, meaning less rise in compression.
However, the igniting of the fuel-gas mixture is only within tight tolerances. Let us look at the starting behaviour of my particular engine: if really cold it needs a few turns until firing up. Now what about fuel management?
Theoretically, on a perfect engine (ignition and) fuel injection will lead to an instant startup. Obviously not here, the engine needs one or two turns until igniting. Therefore it may be deducted, that the first fuel injection is on the lean side, as not ignited some of the left over fuel is enriched with the second shot from the fuel injection thus giving a more rich mixture, which is then ignited in the next turns of cranking.
Obviously, igniting the mixture on a cold engine is a critical condition. The fuel-air mixture has to be in tight tolerances to get ignited. To correct this condition there are two possible ways:
This comes basically to two possible solutions:
dry the engine or try to rise the willingness for igniting. Drying the engine is described here in the forum as well as by Jaguar. If you have a modern engine with catalysator in my opinion there is no other way if you want to keep things as they are, not detoriating any of the emission-components.
Squirting oil into the engine means improving sealing and thus rising compression - rising compression is a very good way to improve the willingness of igniting the fuel-air mixture. If you have an old engine without emission-components it may be worth a try, nevertheless I have a feeling that something along the line should be wrong, if a measure like this would be necessary.
So my decision would be (as it has been) first to try the procedure Jaguar has given in his handbook, means pedal to the floor and drying the engine, then start all over. If this would not help (still knowing, nothing else should be wrong) I would take out the spark plugs, put them into mild heat (an oven on minimum heat) to completely dry them as well as to check them at this occasion, also cranking the car to ventilate the cylinders (with the plugs still out). Actually, if this does not help on my engine after this I would go into workshop-troubleshooting, because then there is something severe in question along the line.
Squirting oil into the engine (no emission control components given) may help to get it started - however I doubt, if such a drastic measure would be appropriate for an otherwise sound and healthy engine. Surely it should work, most probably even to a greater degree of deterioration of the engine, however I would be reluctant to use it if not in the cause of a special reason for that.
Provided, there has been no obvious sign of any difficulty with the engine. That means, ruling out mechanical problems other than deterioration by wear.
On modern engines with electronic management of ignition you might rule out that there is a problem with the drop of the voltage due to the starter motor. That leaves two options on an engine not starting up: fuel and ignition.
Although it cannot be ruled out: if the engine had been running before now why should suddenly all of the ignition fail? its most improbable. On an engine with a lot of cylinders a failure of all of the spark plugs can be ruled out - a failure would be in one or two spark plugs, resulting in an sputtering engine.
What is in continuous change is the supply of fuel. So here I would expect the reason for a problem (with electronic ignition management).
Now provided, the fuel supply is available. Take a close look to the conditions in the engine:
The engine is cold, this meaning, the pistons are not yet expanded by heat and thus give more room to the cylinder walls, meaning less sealing, meaning less rise in compression.
However, the igniting of the fuel-gas mixture is only within tight tolerances. Let us look at the starting behaviour of my particular engine: if really cold it needs a few turns until firing up. Now what about fuel management?
Theoretically, on a perfect engine (ignition and) fuel injection will lead to an instant startup. Obviously not here, the engine needs one or two turns until igniting. Therefore it may be deducted, that the first fuel injection is on the lean side, as not ignited some of the left over fuel is enriched with the second shot from the fuel injection thus giving a more rich mixture, which is then ignited in the next turns of cranking.
Obviously, igniting the mixture on a cold engine is a critical condition. The fuel-air mixture has to be in tight tolerances to get ignited. To correct this condition there are two possible ways:
- one, to correct the condition into this state, what is expected by a cars management systems. Basically this means , drying the engine by shutting of the fuel and pumping air through the cylinders until the surplus of fuel is gone, then starting from the beginning.
- Another one is increasing the willingness to ignite, one would be to use better ignitable starter fluid and another one to increase compression.
This comes basically to two possible solutions:
dry the engine or try to rise the willingness for igniting. Drying the engine is described here in the forum as well as by Jaguar. If you have a modern engine with catalysator in my opinion there is no other way if you want to keep things as they are, not detoriating any of the emission-components.
Squirting oil into the engine means improving sealing and thus rising compression - rising compression is a very good way to improve the willingness of igniting the fuel-air mixture. If you have an old engine without emission-components it may be worth a try, nevertheless I have a feeling that something along the line should be wrong, if a measure like this would be necessary.
So my decision would be (as it has been) first to try the procedure Jaguar has given in his handbook, means pedal to the floor and drying the engine, then start all over. If this would not help (still knowing, nothing else should be wrong) I would take out the spark plugs, put them into mild heat (an oven on minimum heat) to completely dry them as well as to check them at this occasion, also cranking the car to ventilate the cylinders (with the plugs still out). Actually, if this does not help on my engine after this I would go into workshop-troubleshooting, because then there is something severe in question along the line.
Squirting oil into the engine (no emission control components given) may help to get it started - however I doubt, if such a drastic measure would be appropriate for an otherwise sound and healthy engine. Surely it should work, most probably even to a greater degree of deterioration of the engine, however I would be reluctant to use it if not in the cause of a special reason for that.
Last edited by tums; 10-23-2010 at 01:21 PM.
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