Has hesitation when accelerating
09-03-2015, 09:52 PM
#1
Advanced
Thread Starter
Has hesitation when accelerating
Can someone advise me as to what may the problem regarding
a 1984 ?.. It has hesitation when accelerating. New Throttle Body Positioning Body Sensor and HEI Module didn't help.
a 1984 ?.. It has hesitation when accelerating. New Throttle Body Positioning Body Sensor and HEI Module didn't help.
09-03-2015, 10:51 PM
#3
02 old?
09-03-2015, 11:07 PM
#4
Team Owner
Pro Mechanic
First thing you ALWAYS check on a CFI car when encountering drivability issues -especially a "hesitation/bog", etc.....is fuel pressure. Check your fuel pressure, and do it while driving....while the symptom is occurring.
09-04-2015, 01:29 AM
#5
Advanced
Thread Starter
Hesitation occurs regardless if the vehicle is cold or at operating temperature, also
hesitates at full, mid, and slow throttle.
Regarding fuel pressure test, No it has not been tested . Please note; the vehicle belongs to a friend and i have been helping him to determine what the problem could be. Thanks to
everyone for your suggestions.
hesitates at full, mid, and slow throttle.
Regarding fuel pressure test, No it has not been tested . Please note; the vehicle belongs to a friend and i have been helping him to determine what the problem could be. Thanks to
everyone for your suggestions.
09-04-2015, 02:18 AM
#6
Safety Car
Next question: How do you check fuel pressure on a CFI engine? It's not as easy as later engines. Has the fuel filter been changed recently? A dirty filter will obviously affect fuel pressure at the most critical time . . . during acceleration, when fuel flow is highest!
Changing the fuel filter is an excellent time to check the fuel pressure. Remove the old filter, then put a straight piece of fuel line in place of the filter, with a "T" in this piece of fuel line. That's where you can connect your fuel pressure gauge! Hopefully, the car will run better with the dirty fuel filter out, but it's a good idea to check the fuel pressure while you're doing this job.
Changing the fuel filter is an excellent time to check the fuel pressure. Remove the old filter, then put a straight piece of fuel line in place of the filter, with a "T" in this piece of fuel line. That's where you can connect your fuel pressure gauge! Hopefully, the car will run better with the dirty fuel filter out, but it's a good idea to check the fuel pressure while you're doing this job.
09-04-2015, 10:28 AM
#7
Team Owner
Pro Mechanic
Spec for that car is 9-13 PSI, but most if not all who have had one, agree that they run better in the 12-13 range.
09-04-2015, 08:51 PM
#8
Advanced
Thread Starter
I asked him if he had changed the fuel filter lately, he stated that he had, so I didn't
give it a second thought. After reading your post I asked him when he changed the fuel filter , he replied, " they changed it at the shop when I had new shocks installed approx.
3 years ago"..
Well to make a long story short, he located the receipt and they did not replace the fuel filter. New filter installed and problem resolved.
Thank you all for helping me to help my friend, he is now a happy camper compliments of Corvette Forum..
give it a second thought. After reading your post I asked him when he changed the fuel filter , he replied, " they changed it at the shop when I had new shocks installed approx.
3 years ago"..
Well to make a long story short, he located the receipt and they did not replace the fuel filter. New filter installed and problem resolved.
Thank you all for helping me to help my friend, he is now a happy camper compliments of Corvette Forum..