Carb issues

[TrixNFlix]

Right I have done 150 fault free miles since last Thursday, then broke down last night, in asda carpark.
This is my normal starting procedure

choke on full
crank for 2 seconds, which it starts on
let the revs rise to 2000 rpm the drop choke down to half, so it is idling about
1500 revs
drive off!

I noticed at dinertime when I popped to the post office that it wouldn't start using the normal procedure, while on full choke had to give a few pumps of the accelerator, and noticed the revs were not rising very quickly when it had started, resulting in me having to use the accelerator pedal again. Once warm it was fine. Came back to it from the post office, and started first crank, as it does once warm.

I had the same starting issues as at dinnertime when I came to start the car last night. Stopped at asda, came back to it after being in asda for 5 mins, and couldn't get it to start. All I could get was the starter motor cranking.So while waiting for the breakdown guy, I checked I was getting a spark, although it looked a little weak, fuel pump was working, fuel was passing the regulator, compression was fine.

So waited about 45 minutes for the breakdown guy, cranked it over for him, and it started straight away! Talked through everything with him and we couldn't realy come to a conclusion. Anyways traveled 25 miles fault free. Left it outside my house for an hour, came to start it to put it on my drive, and nothing again.Had to push it on to the drive. What I noticed this time was, carb top was still pretty warm. Opinions please chaps. Regards andy

[jonnyshaw49]

hi mate is the fuel pump suspect?? i once had a fuel pump that would work when it wanted. can you hear it priming? also have you got 4 psi coming to the carb on idle? and have you cleaned all the jets and emulsion tube? if you have a weak spark it might be at the ignition side, are your spark plugs telling you anything?? its a case of elimination work through the fueling and the ignition bit at a time, this might be irrelevant but i once had a car and it would struggle to start when cold but when warm everytime, narrowed it down to the shells on the crank being tight and the starter wouldnt turn the engine over when cold, even tried a new starter same happend, so it had to be all re shelled,

[TrixNFlix]

hi mate is the fuel pump suspect?? i once had a fuel pump that would work when it wanted. can you hear it priming? also have you got 4 psi coming to the carb on idle? and have you cleaned all the jets and emulsion tube? if you have a weak spark it might be at the ignition side, are your spark plugs telling you anything?? its a case of elimination work through the fueling and the ignition bit at a time, this might be irrelevant but i once had a car and it would struggle to start when cold but when warm everytime, narrowed it down to the shells on the crank being tight and the starter wouldnt turn the engine over when cold, even tried a new starter same happend, so it had to be all re shelled,

Fuel pumps fine
fuel reg is fine
starter is fine
shells are fine

The cold and warm start problems that you mention I dont think are a factor in this case. Just to mention again, once it's up running there are not problems with any hesitation, on or off boost, and also no problems with the idle. Also the breakdown guy mentioned how well the engine sounded. Anymore ideas from anyone before I rebuild another carb.

[Brigsy]

Full choke might be flooding it?

Whip the plugs out & have a look at them. When i used to run dodgy jetting in the past my plugs used to soot up causing starting probs.

[James5]

Andy it sounds fuel related to be honest when it next happens try the following:

remove the fuel pump relay, bridge the red and White wires for say 20secs then start the car and see if it does start this method will just push fuel into the carb without the engine running so if the carb fuel has emptied or evaporated due to high heat.


Right I have done 150 fault free miles since last Thursday, then broke down last night, in asda carpark.
This is my normal starting procedure

choke on full
crank for 2 seconds, which it starts on
let the revs rise to 2000 rpm the drop choke down to half, so it is idling about
1500 revs
drive off!

I noticed at dinertime when I popped to the post office that it wouldn't start using the normal procedure, while on full choke had to give a few pumps of the accelerator, and noticed the revs were not rising very quickly when it had started, resulting in me having to use the accelerator pedal again. Once warm it was fine. Came back to it from the post office, and started first crank, as it does once warm.

I had the same starting issues as at dinnertime when I came to start the car last night. Stopped at asda, came back to it after being in asda for 5 mins, and couldn't get it to start. All I could get was the starter motor cranking.So while waiting for the breakdown guy, I checked I was getting a spark, although it looked a little weak, fuel pump was working, fuel was passing the regulator, compression was fine.

So waited about 45 minutes for the breakdown guy, cranked it over for him, and it started straight away! Talked through everything with him and we couldn't realy come to a conclusion. Anyways traveled 25 miles fault free. Left it outside my house for an hour, came to start it to put it on my drive, and nothing again.Had to push it on to the drive. What I noticed this time was, carb top was still pretty warm. Opinions please chaps. Regards andy

[TrixNFlix]

Andy it sounds fuel related to be honest when it next happens try the following:

remove the fuel pump relay, bridge the red and White wires for say 20secs then start the car and see if it does start this method will just push fuel into the carb without the engine running so if the carb fuel has emptied or evaporated due to high heat.

James it's 100% not the fuel pump, as when I was waiting for the breakdown guy I took the fuel line off the carb, into a lucozade bottle, and everytime i cranked i got alot of fuel. Worn needle valve?

[Ricardo]

Full choke might be flooding it?

Whip the plugs out & have a look at them. When i used to run dodgy jetting in the past my plugs used to soot up causing starting probs.

Yeah, instead of using full choke just pump the pedal 2-3 times then crank it over.

[TrixNFlix]

Yeah, instead of using full choke just pump the pedal 2-3 times then crank it over.

Tried it both ways guys, with the same conclusion.

[Markey Mark (BD)]

When you operate the throttle whats the acc pump jet doing?

[TrixNFlix]

When you operate the throttle whats the acc pump jet doing?

It's not leaking. Diaphragm is fine.

In answer to brigsy, the plug looked a bit sooty, but I had only driven 1 mile to asda on half choke, so it still hadn't had time to burn of the excess. I forgot to mention this is a standard carb.

[Markey Mark (BD)]

It's not leaking. Diaphragm is fine.



Is it squirting fuel out the nozzle nicely when you press the throttle

[TrixNFlix]

Sorry mark getting my parts mixed up. It's coming out of the copper pipe nice and steady, not dripping. :agree:

[Markey Mark (BD)]

Sorry mark getting my parts mixed up. It's coming out of the copper pipe nice and steady, not dripping. :agree:

Thats good, just making sure as if this isn't squirting it can be a git to start

[TrixNFlix]

Not even seen the car for a few weeks now.Rebuilt two carbs, and have a spare top half of carb that's been de-choked and de-spindled, so when I get a day off work I will experiment. :rolleyes:

[TrixNFlix]

Fecked around with it for a day , trying a few carbs, seems to be ok now, i can only assume that the carb bowl was emptying/ evaporating when switched off. Im still getting a hot start problem, but not as bad as before. Changed alloy carb tops too, and the one on now doesnt seem to absorb as much heat as the last one, whether this was a restriction in the carb or the alloy top i dont know. :scratch: Managed to fuel it up and start it again just now :scared: i was crapping it, will it start wont it. :laugh:.Something tells me that the c1j found out that i was messing around with the b18ft, :wasntme: