Hey guys i need your help,my car is starting hard,but when i give it more than 50% thottle it starts alot faster.If i just let it crank it will start but it stinks like gas,any ideas would be great,thanx.Bye the way it is a l98

 

Before you turn the key to START, turn it to ON and let it sit for a few seconds. You should hear a slight whine coming from the rear of the vehicle; this is the fuel pump priming the fuel rails on the intake manifold. After this noise stops, try starting the car.

If it starts up much better, it's probably an issue relating to the initial priming of the fuel system. That could mean anything from a bad fuel pump to a clogged filter to dirty injectors.

Since your car is an '88, I believe it still has the cold start injector (it's been a while since I've worked on these F-bodies)... this "ninth injector" is designed to inject fuel at startup when the engine is cold (coolant temperature is below a specified value). Do you have starting problems when the engine is hot or cold? Both?

 

hey man thanks for your response,the car starts better on its first start up of each day.But it usually does it hot or cold,but one thing i noticed is that if it cranks for a while it will smoke when i start it.The car runs awsome when its started though.It has a accel ignition on it,and when i bought it if it was cold out,when you would start it it would die,then restart it and it would be fine,the guy said he thought it was the ignition system,but why woul stepping on the gas peddle make it start better if that was true.thanx in advance for your thoughts

 

The smoke you experience on startup is probably related to old valve stem seals; it's a common problem and allows a small amount of oil to enter the combustion chamber which, when ignited, turns into a bluish smoke. Though, that usually only happens if the car has sat a few hours and the oil in the valvetrain has had a chance to seep through.

I know that throwing parts at a vehicle is not the most ideal way to fix things, but have you taken a look at the ignition module under the distributor rotor? A faulty module has been known to cause starting issues, and I believe it was part of the starting problem I used to have on my Camaro. Some auto parts stores will test it for free, so you really aren't losing anything (just your time) if you pull it out and check it.

 

thanks for your help i will try that and see what hapens

 

What color is the smoke? When you start it without giving it throttle, does it spit and studder before resuming normal idle?


I had a hard start condition just like you. And 50% + throttle would make it start much quicker (I believe doing this puts the computer in some kind of flood control and the injectors don't fire, not too sure though). When it did start, it stunk like gas.

Anyway, turns out I had leaky fuel injectors. They would drip when I turned the car off and flood the engine. And the only way I could start it quick was to give it throttle.

 

Hey thanks for your response,the smoke is blueish white,but if i let it crank it seems worse,if i give it throttle it barely smokes at all,but definately stinks like gas,and it will kinda run rough for like 2 seconds and then is fine,but one thing i notice is thatit seems to have a slight stumblefrom600 to1000 rpmsand then is fine.

 

Just as a side note, in the PROM calibration chip, there is a table called "Crank Fuel PW vs. TPS." Basically, it's a multiplier that adds a certain amount of extra time to the duration of the fuel injectors at startup, in relation to the position of the gas pedal. Interestingly, these values are "1.00" for nearly all throttle percentages (they become "0.00" for everything above 87.5%). In essense, this means that the amount of fuel the injectors supply to the engine during cranking does NOT depend on the position of the gas pedal. I have not seen anything else that is related to the accelerator and fuel control.

Now, this is for an '89 MAF car ($6E mask), which is different than what your car operates under, but there's probably something equivalent to this table in your calibration.

This tells me that maybe it's not a fuel issue, but something else that changes when the accelerator is depressed. Still, I'm not sure what that may be. Just some food for thought.

 

Thanks for your help,I am going to replace the ignition control module and see if that helps,if not maybe i will bring it to gm and bite the bullet.The car is awsome exept for this stupid problem,thanks again for your help.