fuel issues...i think
Thread Starter
|
Junior Member
Joined: Jul 2007
Posts: 5
Likes: 0
From: Saskatoon, Sask
fuel issues...i think
The truck is 97 f150 4x4 auto with a 4.6 with about 80 thousand miles
Here are the codes:
P1299 cylinder head overtemp protection active
P0136 O2 circuit (bank 1, sensor 2)
P0156 O2 circuit (bank 2, sensor 2)
This problem started with stumbling while under load and progressed to stalling to the point where it could not be started again without several attempts. sometimes the vehicle will stay running, but will idle eractically and it can only be driven about 30 mph. i noticed that when the problem occurs that the fuel pump relay clicks wildly in the power distribution box. i changed the relay and nothing has changed. It appears that whatever control the fuel pump relay is failing. It should be noted that under cold start up the problem will also occur. Any help would be greatly appreciated.
-mike-
Here are the codes:
P1299 cylinder head overtemp protection active
P0136 O2 circuit (bank 1, sensor 2)
P0156 O2 circuit (bank 2, sensor 2)
This problem started with stumbling while under load and progressed to stalling to the point where it could not be started again without several attempts. sometimes the vehicle will stay running, but will idle eractically and it can only be driven about 30 mph. i noticed that when the problem occurs that the fuel pump relay clicks wildly in the power distribution box. i changed the relay and nothing has changed. It appears that whatever control the fuel pump relay is failing. It should be noted that under cold start up the problem will also occur. Any help would be greatly appreciated.
-mike-
Last edited by saskf1504x4; Nov 27, 2007 at 10:19 AM.
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
It's hard to tell the full story but the codes suggest one or more of the following.
The temp sensor detected an over heating condition from either a cooling system problem and/or with the 136/156 codes. Possibly the cats have plugged and caused motor overheating and won't let the motor run.
The fuel issue you see is possibly the temp sensor 'active' has put the PCM into limp mode so the motor is not damaged from the fault by trying to run it.
The 136/156 codes are the down stream cat sensors telling you they can't see the right conditions 'after' the cats. Possibly plugged cats or some fault with them. If the cats or any place in the exhaust causes really excess back pressure the motor will have a hard time running if it can't exhaust and could overheat at some point, tripping the sensor to an active code. Or it could be the cooling system. Or a combination of them.
It has to be sorted out by looking at the areas the codes are implicating.
They could be cause and effect type conditions
The temp sensor detected an over heating condition from either a cooling system problem and/or with the 136/156 codes. Possibly the cats have plugged and caused motor overheating and won't let the motor run.
The fuel issue you see is possibly the temp sensor 'active' has put the PCM into limp mode so the motor is not damaged from the fault by trying to run it.
The 136/156 codes are the down stream cat sensors telling you they can't see the right conditions 'after' the cats. Possibly plugged cats or some fault with them. If the cats or any place in the exhaust causes really excess back pressure the motor will have a hard time running if it can't exhaust and could overheat at some point, tripping the sensor to an active code. Or it could be the cooling system. Or a combination of them.
It has to be sorted out by looking at the areas the codes are implicating.
They could be cause and effect type conditions