Problems starting when warm

Submitted by lyndsnjasp on

Forum: 

Hi i have a 1994 elxi sportrak and in the last two days i have had a problem starting it, when the engine is cold its fine but if i drive the car and stop to nip into a shop or leave it for 5 mins it then wont start, and i have to leave it for 20mins +. It is also affecting the idle as it keeps dropping revs then going back to idle. The starter motor is fine, it has battery power, fuel is getting to the engine fine, the spark plugs have been replaced, the leads are all fine. Any help or advice on what could be wrong or what else to check?
cheers

STP

Submitted by Mace on

Could be a sticking choke. Try a fuel additive to clean the system.
[PS .. My local £1 shop has bottles of STP unleaded petrol treatment on sale. Cleans the fuel system etc. Bought four, what a bargain!]
If you have a carb version you can pour a small quantity of redex directly into the carb after removing the air filter. Get the engine hot and keep the revs high ... then slowly pour the redex into the orifice. Keep the revs high until the smoke clears. Then snuff over the orifice with a clean rag and let the engine 'suck' at the cloth .... keep the engine revs high. The sucking sucks away any muck from the carb's jets etc. Use a clean COTTON cloth, none fibrous.

Problems starting when warm

Submitted by oldminiman on

YOURS IS AN INJECTION MODEL SO THE CHOKE THEORY IS NOT A PROBLEM I WOULD BE CONCERENED ABOUT. THE ECU WILL ENRICH THE MIXTURE TO AIR RATIO WHEN THE MOTOR IS FIRST STARTED AND THEN CHECK IT CONSTANTLY AND WILL ADJUST THE MIXTURE WHILST THE MOTOR IS RUNNINTO SUIT VARYING CONDITIONS, TEMPERATURES, SPEED ETC.

I WOULD LOOK AT THE IGNITION AND IN PARTICULAR THE COIL AS I HAD SIMILAR PROBLEMS OF DROPPING REVS AND IMPOSSIBLE STARTING BUT NOT ALL THE TIME. EVENTUALLY IT WENT ALTOGETHER BUT BEFORE THAT IT OFTEN MISSED AS I PULLED AWAY AND JUST WAS HESITANT. CHECK ALSO THE DISSY AND THE ROTOR ARM FOR WEAR, CRACKS AND TRACKING MARKS INSIDE. IN THE CASE OF MINE THE COIL WAS SENDING ALL THE POWER TO EARTH AND I WAS GETTING A SHOCK AFTER A RUN FROM THE BODY AS WELL. NEW COILS ARE EXPENSIVE FROM THE MAIN DEALER BUT COME UP ON EBAY OR I PAID £40 FROM A LOCAL SUPPLIER IN ROMFORD. BEFORE THAT WAS OBTAINED (I LIVE IN FRANCE AND SPARES ARE RARE) I USED A STANDARD COIL FROM A MINI, ADAPTED THE LT LEADS TO FIT AND THAT DID FINE. IF YOU HAVE AN OLD COIL IT MAY BE WORTH TRYING (BUT KEEP THE BOOTOM PLUG AND SOME WIRE FOR EVENTUAL REPLACEMENT) I KNOW THERE IS ONE FOR SELL ON EBAY FOR £10 +p&p NOW.

I AM NOT SURE OF YOUR AGE BUT ANGLAS HAD THE VERY SAME HABIT WHEN WARM AND THAT WAS CAUSED BY THE PETROL EVAPORATING FROM THE FLOAT CHAMBER AND I RECALL WAITING AGES TO GET THEM GOING AGAIN WHILE THE MECHANICAL PUMP STRUGGLED TO OVERCOME EVAPORATION. AS YOU ARE INJECTION YOU LUCKILY WON'T HAVE SUCH A FAULT.

HOPE THIS IS OF USE AND GOOD LUCK.
OLDMINIMAN

THE REDEX INJECTOR MIXTURE THEORY IS GOOD AND SHOULD BE ADDED TO FUEL BEFORE A LONG RUN TO KEEP JETS CLEAN FROM TIME TO TIME. IT DOESN'T HARM THE CAT EITHER.

M J Young