Warm Start Issue- Need to give it a little gas
09-16-2010, 04:19 PM
#1
Drifting
Thread Starter
Warm Start Issue- Need to give it a little gas
When starting my 982 cold, it starts perfect, catches right away, no need to touch the gas pedal.
However, sometimes when the motor is warm, I need to feather/blip the gas a little to get it past the initial “catch”. Otherwise, it will catch, but then die. However, once its is fully started, after the quick blip of gas, it runs perfectly with a nice smooth idle and no problems.
Seems to be the same results AC off or on.
Temp II sensor is brand new. Air filter new. Fuel filter new.
Stock everything except air pump mysteriously vanished....
No other unusual symptoms. Engine runs great, sounds great, lots of power.
This is one of those things that is pretty minor, and I am so used to it that I hardly notice, but I'd like to get sorted if possible.
However, sometimes when the motor is warm, I need to feather/blip the gas a little to get it past the initial “catch”. Otherwise, it will catch, but then die. However, once its is fully started, after the quick blip of gas, it runs perfectly with a nice smooth idle and no problems.
Seems to be the same results AC off or on.
Temp II sensor is brand new. Air filter new. Fuel filter new.
Stock everything except air pump mysteriously vanished....
No other unusual symptoms. Engine runs great, sounds great, lots of power.
This is one of those things that is pretty minor, and I am so used to it that I hardly notice, but I'd like to get sorted if possible.
09-16-2010, 10:57 PM
#2
Team Owner
pull the vacuum lines off of the dampers and the FPR smell them for gas
09-17-2010, 12:09 AM
#5
Mine started great when cold but rich and soot from exhaust when warm. Took a blip from throttle as well to run smoothly.
As soon as I pulled the vacuum line off the FPR I smelled fuel. I got a donor FPR from Malcolm and it has always started smoothly and no more soot from tailpipe.
So check the vacuum lines to the FPR and the two regulators for fuel in the vacuum first.
As soon as I pulled the vacuum line off the FPR I smelled fuel. I got a donor FPR from Malcolm and it has always started smoothly and no more soot from tailpipe.
So check the vacuum lines to the FPR and the two regulators for fuel in the vacuum first.
09-17-2010, 03:44 PM
#6
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Fuel injected 928s when you step of the "gas pedal" you are just waving the throttle butterfly letting in MORE air ! Pumping the pedal only shoots in gas on carbureted cars with accelerator pumps.
09-17-2010, 03:53 PM
#7
Drifting
Thread Starter
JB-
I get your drift, that was my understanding too, which is why the symptoms puzzled me. But the symptoms are clear and repeatable. When warm, give it no "pedal" and it catches for a very quick moment and dies. But give it some pedal during the start ( and I mean not much more than the weight of my foot on the pedal, ~1/4" travel), and it catches and keeps running. After that first moment, no other action is required. Idles perfectly with no foot action required. And cold, starts perfectly.
I'm going to give the FPR, vacuum tubes etc the sniff test when I get back to the garage. Other than a few more dead brain cells if there are gas fumes, can't hurt. Heck, might do it a few times just to make sure....
I get your drift, that was my understanding too, which is why the symptoms puzzled me. But the symptoms are clear and repeatable. When warm, give it no "pedal" and it catches for a very quick moment and dies. But give it some pedal during the start ( and I mean not much more than the weight of my foot on the pedal, ~1/4" travel), and it catches and keeps running. After that first moment, no other action is required. Idles perfectly with no foot action required. And cold, starts perfectly.
I'm going to give the FPR, vacuum tubes etc the sniff test when I get back to the garage. Other than a few more dead brain cells if there are gas fumes, can't hurt. Heck, might do it a few times just to make sure....
Trending Topics
09-17-2010, 08:28 PM
#10
Three Wheelin'
Join Date: Apr 2010
Location: Virginia Beach, VA
Posts: 1,295
Likes: 0
Received 0 Likes
on
0 Posts
09-17-2010, 09:55 PM
#11
Rennlist Member
Join Date: Oct 2005
Location: Gatineau, Québec, Canada
Posts: 5,178
Received 1,318 Likes
on
499 Posts
I had the same problem and it was a bad regulator and 1 bad damper.
If the regulator or/and the damper(s) are leaking at the vacuum hose, they are bad and they need to be change.
Good luck.
If the regulator or/and the damper(s) are leaking at the vacuum hose, they are bad and they need to be change.
Good luck.
09-17-2010, 10:58 PM
#12
Team Owner
on the 84 and newer cars there are 2 dampers and one FPR if one of these units is leaking it may be in the best interest to replace them all.
The idea being that if the vacuum diaphram is leaking then the vacuum line will be sucking additional fuel into the intake in liquid form this will richen the mixture and make starting quite difficult.
This issue usually happens after the engine has reached operating temperature.
The idea being that if the vacuum diaphram is leaking then the vacuum line will be sucking additional fuel into the intake in liquid form this will richen the mixture and make starting quite difficult.
This issue usually happens after the engine has reached operating temperature.
