Carb Over Fueling At Low Revs

[toyota_ae71]

Had the exact same problem when i had my 32/36 holley on the 4k.

So i pulled all of the jets out, thoroughly clean them and everything else, and left the carby in good quality degreaser over night, and cleaned it again in the morning.

 

This helped quite abit :y: but it was still doing it, so i downgraded the primary jet a couple of sizes and WOLA fixed that problem. But then it didnt feel the same in the higher revs so i upped the secondary jet too. worked wonders for me, but this was my khanacross car and fuel economy wasnt an issue for me.

 

Maybe worth a try.

[tas_ae71]

thanks felix. i checked the power valve and it holes vaccume. i also visually inspected it and it looks fine.

 

i cleaned all the jets and shit out, pulled everything off and cleaned, blew out and re-assemeballed.

 

the bit that doesnt make sense to me, is if its only a jetting issue then why wasnt it running like this from the start?

 

i was speaking to a fella at a local performance workshop he said we can throw the old girl on the dyno and have a play with the jetting. dyno + AFR meter = win :)

 

beats a f@$ken road test haha.

[tas_ae71]

was in town the other day and it kept fouling plugs and bogging down,

 

i went and got a set of iridium plugs $88 for the set!

 

went home threw them in started it up, hhmm yeah it goes better and seems to pick up a lot better. later in the evening i drove down to the supermarket. was a LOT worse. kept on getting bogged down and when it would clear when you put any sort of load on it, it would start to stall again.

Edited July 1, 2009 by tas_ae71

[tas_ae71]

went to a carb specialist today and had a chat to him about it, he said that its not to change the jetting just yet.

 

part of the problem was that it was running on the main circuit instead of the idle circuit, that is now fixed with a further clean and winding back the idle.

 

its still very boggy and wont rev up until its warm. this is mostly an issue when taking off, if i keep the revs up and change back a gear before i put it under heavy load it should be manageable.

 

its been raining here, went for a test drive tonight, rode the clutch until it was going fast enough in first gear then booted it and revved it out in first grabbed 2nd, thought the clutch was slipping for a second but it was actually wheel spin which i haven't experienced in a straight line for quite some time :wink:

 

will give the carb place a call tomorrow and book it in friday. hopefully ill be able to get to work in the morning!!!

[ade_mc]

went to a carb specialist today and had a chat to him about it, he said that its not to change the jetting just yet.

 

part of the problem was that it was running on the main circuit instead of the idle circuit, that is now fixed with a further clean and winding back the idle.

 

its still very boggy and wont rev up until its warm. this is mostly an issue when taking off, if i keep the revs up and change back a gear before i put it under heavy load it should be manageable.

 

its been raining here, went for a test drive tonight, rode the clutch until it was going fast enough in first gear then booted it and revved it out in first grabbed 2nd, thought the clutch was slipping for a second but it was actually wheel spin which i haven't experienced in a straight line for quite some time :P

 

will give the carb place a call tomorrow and book it in friday. hopefully ill be able to get to work in the morning!!!

 

hi mate, so how does the car go now?

i have had the same problem. but now it won't start.

so i replaced the stock carb with a weber 32/36, abd it still won't start properly.

struggles to start then won't rev over 500RPM then dies.

 

i can't seem to figure it out.

[tas_ae71]

i found it to be the cam timing. it was out by 2 teeth (so a wonder it actually ran).

 

so might pay to check that, fairly sure you have a 4ac sprinter?

 

there are 3 marks (kinda like pointy triangles) on the rocker cover behind the cam gear. take the plastic timing cover off. turn the motor over (19mm spocket on crank bolt) until the small pin hole on the spokes of the cam wheel is lined up with the middle timing mark. then have a look at the timing mark on the crank pully, if its on "0" or within maybe 5 degrees its good enough.

 

then prob check the ignition timing with a timing light.

[Evan G]

its never what you god dam expect!!! i hate that!

 

you should of realised it ran like shit straight after you did the timing belt

 

oh well the joy of owning a corolla :)

[ade_mc]

i found it to be the cam timing. it was out by 2 teeth (so a wonder it actually ran).

 

so might pay to check that, fairly sure you have a 4ac sprinter?

 

there are 3 marks (kinda like pointy triangles) on the rocker cover behind the cam gear. take the plastic timing cover off. turn the motor over (19mm spocket on crank bolt) until the small pin hole on the spokes of the cam wheel is lined up with the middle timing mark. then have a look at the timing mark on the crank pully, if its on "0" or within maybe 5 degrees its good enough.

 

then prob check the ignition timing with a timing light.

 

yeah mate 4ac ADM sprinter.

i will have a look at the cam timing, and give it a go. so how do you adjust/make the adjustment to cam timing? move the belt how ever many teeth require to a line timing correctly?

 

i don't have a timing light, but may purchase one.

Edited August 18, 2009 by ade_mc

[altezzaclub]

ade- You can set the static timing easily by turning the crank to a handful of degrees before the mark you want, take the top off the dizzy, turn on the igition then turn the motor to TDC. You will hear the spark at the moment it fires, might even see it.

 

Move the dizzy until the spark arrives at the timing you want.

 

Dynamic timing (when its running) is controlled by the weights and vacuum system.

[tas_ae71]

its never what you god dam expect!!! i hate that!

 

you should of realised it ran like shit straight after you did the timing belt

 

oh well the joy of owning a corolla :)

 

i didnt do the timing belt,

 

i made a new thread, the belt is skipping teeth.

[Evan G]

jesus ive heard it "can" happen how many k's was it overdue?