I recently had the the timing belt replaced on my 02 Elantra, since then it’s had a problem starting. It won’t start without me pumping the gas and once I let go it hesitates and shuts off. Anyone have an idea what it could be?
That might be an engine flooding problem. Pushing on the pedal opens the throttle valve, allowing extra air into the engine, so it runs like that. but as soon as you let go of the pedal it closes off the air flow and causes the mixture to be too rich so it stalls. Faulty injectors or fuel pressure problem maybe. Sticking EGR valves can cause this problem too. If it happened right after the timing belt job, ask your shop to re-check the valve timing and ignition timing. If it is mis-timed this could result.
Have someone check the Idle Air Control circuit.
One component in the circuit is called the Idle Air Control valve.
https://www.rockauto.com/en/moreinfo.php?pk=2407128&cc=1386503&jsn=328
This component basically controls the engine’s idle speed whenever the gas pedal isn’t depressed.
Sometimes the IAC valve can be removed and cleaned to solve the stalling problem.
And other times, the IAC valve requires replacement.
Tester
Does it run ok as long as you are holding the gas pedal down a little to prevent stalling?
Could also be a valve timing problem caused by the timing belt being off.