1999 Honda Accord Engine quits after warmup

BIGAZHOTRODDER

MEMBER
1999 HONDA ACCORD
4 CYL
FWD
AUTOMATIC
105,000 MILES

When cold, engine starts and runs fine until the temperature comes up. Then the idle speed drops to about 5-600 rpms, gets rougher, then quits. Have replaced all hoses, intake gasket O2 sensor, cleaned idle air control valve, etc. The check engine light is NOT on, no codes come up on the scanner. A supposedly reputable shop had the car for ten days, and said the O2 sensor was defective (changed) and that the intake manifold gasket was leaking ( replaced also). Still have problem. HELP!

3 Replies

MERLIN2021

MECHANIC
17,250 POSTS

Can be this tech bulliten. WRONG ECT VOLTAGE MAY CAUSE HOT NO-START TECHNICAL SERVICE BULLETIN Reference Number(s): HSN 0999-12, � Date of Issue: � September, 1999 Related Ref Number(s): HSN 0999-12 ARTICLE BEGINNING WRONG ECT VOLTAGE MAY CAUSE HOT NO-START Model(s): Honda, All Models With PGM-FI Category: Honda Service News Bulletin No: HSN 0999-12 Date: September, 1999 SERVICE INFORMATION On all models with PGM-FI, the wrong ECT (engine coolant temperature) sensor voltage may cause an intermittent hot no-start without the MIL coming on. To confirm the problem when the engine won't start check ECT sensor voltage; if it's more than 1 V, replace the sensor. At normal coolant temperature, the ECT sensor voltage should be between 0.5 and 0.7 V. If the ECT sensor sends a cold engine signal (more than 1 volt) to the ECM/PCM at normal coolant temperature, the air/fuel mixture will be too rich, and the engine may not start. Page 1 of 1 WRONG ECT VOLTAGE MAY CAUSE HOT NO-START -1999 Honda Accord EX 4/18/2009 or a good size vacuum leak at or near the EGR, That comes online when open loop occurs(hot operation)