don cantrell

Working on 71 mgb,all the emmisson controls were removed before
I got the car. I can get it started only with full choke,then idel it down to
aroumd 2000 rpm,if you open the throttle it sputters,backfires and dies.

I have installed a new fuel pump
new fuel filter
points,cond.
new plugs
new ign. wires
Cleaned fuel bowls and needles
cleaned the line from bowl to main jet
have good fire at plugs,getting fuel to carbs.
static check timming,ok

The car has been setting for over 5 years and needs restoring.
Has the removal of the emmissions parts any affect on the engine?


Thanks,
Don

KimMG

Maybe. Check for vacuum leaks. Make sure the motor is breathing properly.
Below is a link to a check list for Bs that have been sitting awhile.
http://www.theautoist.com/awakening_a_sleeping_b.htm
http://www.mgexperience.net has some technical articles available.

don cantrell

I pluged any openings I could find for vac leak,renewed hose
that goes to back of carbs.this has no effect,same as before.
Engine will run on full choke and still backfires when throttle
is opened.

Don

gerrym

Sounds like vaccum leak but when you take the gas cap off, do you hear a air sound. If so the gas tank is not venting. Line plugged to canister (spiders?). Also check the amount of gas pumping to the carbs. You should get about 8 oz in 30 seconds. If not the pump is not performing good enough to maintain correct flow to carbs.

Flash75

Did you drain out the old gas and check the condition of the fuel tank? Disconnect the fuel line from the tank and run a hose from the fuel pump inlet to a clean jug of gas and try it (do this outside in a safeplace). If it runs good with fresh fuel drain and clean the gas tank. You will probably have to remove the tank to clean it.

Clifton

paul J

I know it's an old thread but, it might help someone else. If the car has been setting for 5 years and it has HIF carbs, or whatever, they have to be pulled and cleaned to remove the gum. It's a big mistake people make when trying to start up an engine that has set too long. HIF carbs are extreamly sensitive to this! If you don't clean them properly, it'll never run right!

PS, The carbs must be completely torn down to clean them! Before doing this, buy the rebuild kits or send them out to a rebuilder, such as Hap Waldrop, www.acmespeedshop.com , in Greenville, SC.

imnezrider

I say you shoud consider adjusting your valves. It "could" be causing the problem. Not to worry...you should tend to this regardless. :-)

Mickey

paul J

If there's no restriction in fuel flow to the carbs, then I still say it has all the ear marks of a dirty carb problem. Probably varnish in the carbs jets. What carbs are they? HS4s or HIFs? If you cleaned the seperate fuel bowls, then their probably HS4s.