993 stalls after 1 1/2 minutes
06-01-2020, 11:17 PM
#1
1st Gear
Thread Starter
Join Date: Oct 2016
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
993 stalls after 1 1/2 minutes
Hi,
1996 993 manual trans.
Engine starts ok, after less than 2 minutes engine stalls. some minutes later starts again condition repeats.
No codes on memory.
Looking for suggestions.
Thanks.
1996 993 manual trans.
Engine starts ok, after less than 2 minutes engine stalls. some minutes later starts again condition repeats.
No codes on memory.
Looking for suggestions.
Thanks.
06-02-2020, 12:01 AM
#2
Rennlist Member
Fuel filter, bad gas, loose vacuum line........
06-02-2020, 05:05 AM
#4
RL Community Team
Rennlist Member
Rennlist Member
Hi Lordri64,
As a shade tree mechanic I may not have a complete answer for you but can suggest things you can look at easily in your back yard before having a professional technician go over your issue for you:
Have you done any work on the car or was there some other event such as a dead battery recently just before the symptoms stalling came up? Your reply may give us Rennlist members specific insights to the root cause of your problem. Otherwise here are some things you can look at:
Andy
As a shade tree mechanic I may not have a complete answer for you but can suggest things you can look at easily in your back yard before having a professional technician go over your issue for you:
Have you done any work on the car or was there some other event such as a dead battery recently just before the symptoms stalling came up? Your reply may give us Rennlist members specific insights to the root cause of your problem. Otherwise here are some things you can look at:
- First, disconnect the battery let the car sit for a few minutes, and reconnect it. This will force the DME engine controller to relearn mixture settings to maintain idle. See if your problem goes away, if it does you are done.
- Check the voltage of the system when the engine is running and verify it is greater than 13.5 volts as the DME doesn't like running with too low a voltage.
- A bad DME relay is a rule it out item, replace it, although a consistent stall out point probably makes it not the root cause
- Clean the idle valve to rule it out as a contributing factor although it probably is not a root cause. In combination with an intake leak, it may be just enough to cause stalling.
- Vacuum leaks can cause idle issues without triggering an OBD Code so test your car and its ability to build and sustain a vacuum.
The easiest way to do the is to start the engine and have it run for a few minutes even is you need to lightly sustain the running by keeping it a little above idle with your foot. Then shut-off car completely, let the car stand for 10 minutes. Follow this by having someone switch the ignition on without starting the engine while you observe all the Varioram actuators cycle through their test cycle in the engine bay. If they don't move it indicates an inability to build and maintain vacuum via a good size leak somewhere or a check valve failure as the system should have built and retained enough vacuum from previously running to let the actuators cycle.
- An air leak after the airflow sensor on the intake can cause stall-out without an OBD code thrown but it has to be a good size leak so look for a hose that may have slipped off somewhere. There are a ton of potential leak points so if this is the root cause you may need to take the car to a professional to find the leak.
- With the modern requirements for gas stations to meet EPA testing, it is unlikely it is bad gas unless your car has been sitting a very long time without running to use up the existing gas in the tank where condensation and age has degraded the fuel.
- If your fuel filter is the original one that came on your car replace it as a rule-out item. It is unlikely to be a root cause if it has ever been replaced.
- If the ignition wire/caps/rotors were a root or contributing problem the car would throw misfire codes so the absence of codes seems to rule this out.
- Partially obstructed (dirty) fuel injectors are unlikely a root cause but can contribute so once the issue is sorted out, run two or three consecutive tanks of gas through the car with Techron additive added. I do this once a year on all my cars over the years and have never had a fuel injector related issue.
Andy