16 replies to this topic

[mdmenon]

I have a 1991 JDM Mini with HIF44 SU carb and new electronic distributor.

 

Issue:

1. Is a running car which cranks with ease. Recently did a full wiring clean up and car was running after this.

2. Did a new air horn install with 12V draw to the relay from the starer.

3. Car then refused to start for few attempts as in a ignition spark issue (has new fuel pump, filter and clean carb install).

4. Got back to it a week later. It cranked once then the ignition light refused to come on. Key turning did not switch the ignition light or crank the car. The car has been dead since

 

What I have checked so far:

1. Battery voltage is 12.67V. New battery and I keep it charged.

2. Ignition switch brown wire is 12V

3. Starter wire has 12V

4 Starter relay brown wire has 12V

5. Fuse 3 and 4 with brown wire has 12V

6 Checked starter switch continuity on the bench- In off position-12v on brown only; In accessory position-Brown and to light and ignition; in Starter position- Brown and to light and ignition and also to red/white wire to starter.

7. Additionally- The break light rocker switch with red light seems to have a direct 12V feed and works. ( I have disconnected the break light itself though)

 

I have checked all the available posts and could not find a solution; except some immobilizer related solution which believe should not apply to my car with carb. Any pointer will be a great help.

[GraemeC]

Sounds like one of the terminals/connections you have disturbed now has poor connectivity / high resistance.
Enough contact to pass voltage to a voltmeter, but breaking down under high load.

 

Remove, clean and remake the12V starter feed you used to power the relay, and all earth points.

[lordcakes]

You need to sure your earth connections are good (battery to body and engine to body).

Just from the last comment in the post, saying that the ignition light doesn't come on either, this could point to your ignition switch being faulty.

[mdmenon]

Sounds like one of the terminals/connections you have disturbed now has poor connectivity / high resistance.
Enough contact to pass voltage to a voltmeter, but breaking down under high load.

 

Remove, clean and remake the12V starter feed you used to power the relay, and all earth points.

Thanks.Good suggestion.Will make sure every thing is clean.

[mdmenon]

You need to sure your earth connections are good (battery to body and engine to body).

Just from the last comment in the post, saying that the ignition light doesn't come on either, this could point to your ignition switch being faulty.

I was working under the same impression, but on the bench the starter switch showed good continuity for all positions.

[lordcakes]

The last time I had a similar fault it was the interals in the starter motor breaking down and causing a short. You could test this by bypassing your wiring with some jump leads to test it

[sonscar]

Old school bodger here,Leave ign OFF. short large battery terminal on starter to solenoid run terminal(red/white or white/red?) and the engine should turn.If it does then connect a live to the positive of the coil and try again,it should crank and start.Do not leave this wire connected without the motor running as it will overheat the coil.Make sure neutral is engaged and take care as the battery is powerful even when flat,and do not run yourself over.

Is there a start relay?it could be faulty holding the starter in mesh effectively shorting out the battery.

If the engine runs it is none of the coil and dissy and if the engine will not turn it is the solenoid or starter.

Be careful and give it a try.Steve..

[mdmenon]

Thanks for all the comments. I had some luck. After cleaning up the starter terminals and the starter switch. The ignition works and car does crank over, however it refuses to start or show life of fuel ignition. I noticed the following now:

1. Checked spark on all the plugs and I do have spark. I did clean them up and checked the gap and all seem to be good.
2. I removed the carb suction chamber and checked the piston damper. I have been using the recommended 3 in 1 oil, however I noticed that the piston damps well on the way up, but does not on the way down. Does it need to damp on the way down? I recall reading that the piston damping needs to be measures in seconds to ensure it damps correctly. Is there a specification for this?
3. Looking down into the section chamber opening I wanted to adjust the jet. However on turning the jet adjusting screw in both directions I noticed that the jet was not rising or lowering. A month back when I had serviced the carb, I found the float chamber and jet full of dirt. The jet at that time was jammed in its cavity. I finally removed, but decided to reuse the jet since jet seemed good, did not have any damage and was moving in the cavity freely by hand and with the screw. Is a new jet recommended? I am assuming I have to change the jet and needle as a set. what is the spec recommended? Could this be a cause  for fuel not coming through?
4. While I do that I also want to install a new  jet adjusting lever , possibly one that is not bimetallic. This part seems to be not available, anybody knows where to find it?
5. Finally, all this is to get the car started. Since I have new fuel pump, I am assuming the issue lies in the carb. I intend to test with starter fluid over the weekend to test this theory, in the meanwhile any ideas you may have will be most helpful.

Thanks folks!

[tamlamotown123]

Hi I had a similar problem earlier this year ,took tens of hours to solve.

Have you touched or split the main connection block from the loom to the indicator stalk under the dash/ steering wheel ?

You may have one of the pins not fully engaged, good luck

[richmondclassicsnorthwales]

The pot should rise and fall quite easily.

 

If the pot is rising ok, but not falling all the way down, then that would say to me the jet centering is not right

 

This to me seems the case because you mention you can't see the jet moving, and that it is stuck, and not being central would cause this.

 

If you have taken the jet collar off at some point, this could be a likely cause

 

I don't know what work on the carb you will have done, so I am just firing in a few suggestions

[mdmenon]

Hi I had a similar problem earlier this year ,took tens of hours to solve.

Have you touched or split the main connection block from the loom to the indicator stalk under the dash/ steering wheel ?

You may have one of the pins not fully engaged, good luck

The loom was taken out and some burnt wires replaced. All wiring was tested and worked. However this is a possibility since I used the existing pins which were not exactly mint. I will check and correct. Thanks!

[mdmenon]

The pot should rise and fall quite easily.

 

If the pot is rising ok, but not falling all the way down, then that would say to me the jet centering is not right

 

This to me seems the case because you mention you can't see the jet moving, and that it is stuck, and not being central would cause this.

 

If you have taken the jet collar off at some point, this could be a likely cause

 

I don't know what work on the carb you will have done, so I am just firing in a few suggestions

I dismantled the carb, cleaned and built it with a repair kit. I am not sure I understand what a jet collar is, however I plan to put a new jet and needle assembly since this is one part I did not replace when I did the carb service. Is there a procedure to follow to ensure jet centering? Will the new parts ensure that the jet will be centered? Thanks for the suggestion.

[cal844]

When you rebuilt the carb did you refit the collar that holds the needle in place?

Did you fit the needle flush with the base of the piston?

Both of these will cause issues

[richmondclassicsnorthwales]

The long and short of it is that the needle does not rub hard against the jet, hence the piston not dropping properly

 

It may be better when you get a new jet, take off the carb to do the job, it will be harder doing the job on the car

 

With the carb in your hands, have the rear elbow off the carb so you can raise the jet easier with your finger

 

It can be as easy as just twisting the jet bearing very slightly back or forth a fraction, but you have to make sure the bearing is also quite clean

 

The outside of the jet needs a clean jet bearing surface.

 

You also have to make sure the jet bearing is fully home

[mdmenon]

When you rebuilt the carb did you refit the collar that holds the needle in place?

Did you fit the needle flush with the base of the piston?

Both of these will cause issues

No I did not change the needle of disassemble it. I attempted, but could not remove the needle even after removing the lock screw.