losing spark at idle
Thread Starter
|
New User
Joined: Aug 2006
Posts: 20
Likes: 0
losing spark at idle
ok guys this truck is getting to be a real pain. 1989 f250 351w. auto.
just channged the ecm because i wasnt getting any codes. now i have a code for egr.(33). i assumed my stalling issue discussed in an earlier post would be cured or at least being able to pull codes would point me in the right directon. but alas no such luck. so heres what i have now. the truck will start right up and idle for a period of time. from several minutes to a few seconds. then shut down. sometimes it will start right back up. and die again other times it wont start. checked for spark with a screwdriver and i get one spark(ARC). then nothing. this is straight from the coil. i replaced the coil and comp. dist. several months ago. so is there a way to test the pick up coil and the tfi without pulling the dist? or does anyone have any ideas what else may be wrong. the rotor is turning by the way. i appreciate all the help i've been getting from here. so basicaly i have an intermittent spark issue. and the spark doesnt look real hot. this only seems to happen when at idle but it is getting worse, thanks again
just channged the ecm because i wasnt getting any codes. now i have a code for egr.(33). i assumed my stalling issue discussed in an earlier post would be cured or at least being able to pull codes would point me in the right directon. but alas no such luck. so heres what i have now. the truck will start right up and idle for a period of time. from several minutes to a few seconds. then shut down. sometimes it will start right back up. and die again other times it wont start. checked for spark with a screwdriver and i get one spark(ARC). then nothing. this is straight from the coil. i replaced the coil and comp. dist. several months ago. so is there a way to test the pick up coil and the tfi without pulling the dist? or does anyone have any ideas what else may be wrong. the rotor is turning by the way. i appreciate all the help i've been getting from here. so basicaly i have an intermittent spark issue. and the spark doesnt look real hot. this only seems to happen when at idle but it is getting worse, thanks again
Fleet Owner
Joined: Aug 2005
Posts: 23,668
Likes: 301
From: Easton,Ks
I have a feeling that you have spark and the EGR valve is causing the problem (stuck open).
A 33 means:
Service Code 33 in Key On Engine Running indicates that the EVP sensor input did not change after the EVR solenoid was instructed by the processor to open the EGR valve.
This does not indicate what I said above but the way the engine is running it sounds like it is open to me.
You do not have a pick up coil, you have a PIP sensor.
To check the PIP sensor in the distributor you put a DVM on the PIP wire and it should read 6 to 7 volts. The PIP sensor in the distributor is not a coil and you can not check for resistance. In other words it is not a pick-up coil like in the DS II systems. It is a vane switch in an encapsulated package consisting of a Hall effect device on one side and a permanent magnet on the other side. Also called a stator.
All of test for the TFI that I know of involves checking resistance. This may work for a dead TFI but for one that works cold and quits warm it would be hard to check it this way. Most of TFI modules fail when hot.
A 33 means:
Service Code 33 in Key On Engine Running indicates that the EVP sensor input did not change after the EVR solenoid was instructed by the processor to open the EGR valve.
This does not indicate what I said above but the way the engine is running it sounds like it is open to me.
You do not have a pick up coil, you have a PIP sensor.
To check the PIP sensor in the distributor you put a DVM on the PIP wire and it should read 6 to 7 volts. The PIP sensor in the distributor is not a coil and you can not check for resistance. In other words it is not a pick-up coil like in the DS II systems. It is a vane switch in an encapsulated package consisting of a Hall effect device on one side and a permanent magnet on the other side. Also called a stator.
All of test for the TFI that I know of involves checking resistance. This may work for a dead TFI but for one that works cold and quits warm it would be hard to check it this way. Most of TFI modules fail when hot.
Last edited by subford; Aug 26, 2007 at 09:02 AM.
