Hard start-hot-1999 Chev 3500

SOURCE: 96 Ford truck engine lIght will not go away.

this is the problem with code readers they bwill tell you the code and sometimes even have a reset feature. However they do not tell you the parameters and don't have an drivability feature so you can not test the ecm and all the sensors or modules while engine is running. diagnostic scan tools are very expensive and hard to use unless you have been trained to do so and PEP BOYs is not what I call real reliable mechanics to begin with. Now I concure with toddG on his reasoning in what might be the potential fault. if your vehicle is running rich or lean your O2 sensor will pick this up on the exaust side, however it is not the sole sensor responsible for the ecm adjusting the fuel air mixture.. you stated that you have switched out several o2 sensors and the fuel pressure regulator, but there is also you mass air flow sensor, your TPS sensor, as well as your map sensor these are worth checking out and just because a faulty sensor is the problem doesn't mean you will get a code each time. the system is built with redundancy in order to keep the vehicle running. in order to get the best possible diagnois take it to a shop where they have a full diagnostic scanner this will have not only OBD1 and OBD2 but cam protocol as well. while the tech is scanning the vehicle he will be able to see how the engine is performing under realtime conditions. please rate this as well as change the rating for toddg because he did offer a valid suggestion

Patricia Mitchell

• 41 Answers
• Posted on May 23, 2008

SOURCE: 1989 BMW 735i Hot start issue

You might want to try replacing your throttle return spring, or at least lift the hood and see if here is a change while it smooths out..

SOURCE: 2002 gmc yukon, rich fuel code, low fuel pressure @40

you may have two oxugen sensors on your yukon. if so the oxygen sensor that controls that bank may be bad. from what you mentioned in your complaint, it sounds like it is the oxygen sensor.

SOURCE: 1999 Pontiac Grand Prix intermittent problem runs rough

i have had two of these problems both on grand prix's , both turned out to be a mass air flow meter. but nethier set a code for the sensor.

SOURCE: 2001 Tahoe: Hard to start, idles rough, check engine light on.

Flashing check engine light is missfire, fuel pump probably causing multiple tries to start.Having to build fuel preasure,vac leak on one side of intake probably causing rich/lean condition.Also check back preasure to cat ,Sound like you are moving down right track.Mas air flow would probably set lean code bank1 and lean code bank2