Strage Problem, came out of no where

[MrMarty51]

the second one was 3 flashes no pause - it did that 3 times too

UHHHhhh,friend,You better run,that comes out to code "666".

 

[notverrysmart]

Ok, so I rechecked, it flashed 2 codes
One was 1 flash, pause, then 2 flashes - it did that 3 times as it should
the second one was 3 flashes no pause - it did that 3 times too

I replaced all the vacume lines that I saw, and it's also a brand new MAP sensor

So the second code I'm getting is for the oxygen sensor? whats the easiest way to diagnose if thats the problem

If its a vac leak, which most likely it is because the trans acting up at the same time, the oxygen sensor would see a lean mixture and cause it to throw a code.

 

[jo89k5]

The engine is also knocking, I am just noticeing this today, I don't see any other vacume lines, there are the 2 coming out of the throttle body, and the one out of the back of the intake manifold that T's off the the cruise control and a canister, they have all been replaced

 

[philjafo]

Engine knocking will mess up the timing and you've probably got bigger issues then a vacuum leak.

 

[jo89k5]

Engine knocking will mess up the timing and you've probably got bigger issues then a vacuum leak.

But a big problem out of the blue? I'm thinking it might actually be bad gas because the truck was running fine, on my way home from work I got gas at the local name brand station, then the truck sat till the next morning when it started having the problems

 

[philjafo]

A knock is one of two things, 1 metal banging together from a bad bearing, or 2 preignition detonation, in other words the combustion happening before its supposed to. Either one will destroy an engine if left untreated. Yes a major problem can start suddenly. If you suspect bad fuel the only way to know for certain would be to pump as much out as you can and refill with new.

 

[jo89k5]

So to update everyone, I stopped scratching my own head and took it to the local mechanic my family has used for many years and that I'm quite friendly with. He told me that the banging was actaully the water pump, *phew* and it needs to be replaced, somthing I can do in my driveway.

But the other problem that he's scratching his head about now is that somthing seems to be telling the computer to make the engine run really ritch

Just can't seem to win, just hope it's not a problem with the computer

 

[notverrysmart]

a vac leak would cause the o2 sensor to send a lean signal to the computer which will cause it to send more fuel. Did you ever spray to check for a leak?

 

[HotRodPC]

So how bad is this low idle and trans late shifting? Have you done anything to address code 12? I'm wondeing if the 3 quick flashes isn't meaning, end of codes so all you have is actually code 12.

How about in P? How does it idle and run in P? Is it when you get into gear that it tends to bog down and slow the idle? I'm wondering if the TCC (Torque Converter Clutch) in the Torque Converter isn't dragging or trying to stay engaged. How does it act when you're coming up to a stop sign? Does it act like it wants to lurch forward? Kinda like a manual transmission when coming to a stop and pushing the clutch pedal down???

 

[jo89k5]

a vac leak would cause the o2 sensor to send a lean signal to the computer which will cause it to send more fuel. Did you ever spray to check for a leak?

Yeah I sprayed, no apparent leaks

 

[jo89k5]

So how bad is this low idle and trans late shifting? Have you done anything to address code 12? I'm wondeing if the 3 quick flashes isn't meaning, end of codes so all you have is actually code 12.

How about in P? How does it idle and run in P? Is it when you get into gear that it tends to bog down and slow the idle? I'm wondering if the TCC (Torque Converter Clutch) in the Torque Converter isn't dragging or trying to stay engaged. How does it act when you're coming up to a stop sign? Does it act like it wants to lurch forward? Kinda like a manual transmission when coming to a stop and pushing the clutch pedal down???

The idle is low, same deal in P and N as in OD D and 2 and 1, I was thinking it might be the torque converter but it seems to be just as bad in P and N as in Drive

 

[HotRodPC]

It's still worth considering a bit sicne even in P and N, if it's locking up, it's still dragging more parts than normal and still going to have a drag from the stator in the Converter if it's locking up. Does it feel like it want's to lurch when in D with foot on the brake???

Still worth checking into Code 12 too. What I'm off about, is the late shift of the transmission. 700r4 does NOT have a vac modulator and usually shift points are decided by the TV cable and the Governor. So why is the motor running badly causing a late shift?? That's what has me thinking converter clutch dragging. That will cause a pressure bleed off and CAN cause a delayed shift.

 

[jo89k5]

It's still worth considering a bit sicne even in P and N, if it's locking up, it's still dragging more parts than normal and still going to have a drag from the stator in the Converter if it's locking up. Does it feel like it want's to lurch when in D with foot on the brake???

Still worth checking into Code 12 too. What I'm off about, is the late shift of the transmission. 700r4 does NOT have a vac modulator and usually shift points are decided by the TV cable and the Governor. So why is the motor running badly causing a late shift?? That's what has me thinking converter clutch dragging. That will cause a pressure bleed off and CAN cause a delayed shift.

Yes she wants to lerch but not sure if thats because the engine rpm's are fluctuating so much because she will rev down and then rev back up. Also the intermitant loss of power breaks is also concerning

This is why it's such a strange problem, there is so much going on with it and none of it points to one specific problem

 

[philjafo]

Code 12 is no signal from the distributor, its normal you will always get a code 12 when the engine isn't running, and when it is running its no longer in the same diagnostic mode. When its running and a and b are connected the ses light shows the o2 sensor, light on is rich light off is lean (might have that backwards but you get the idea). Ideally it is on for a bit then off for a bit about the same amount of time.

How old is the o2 sensor? They do wear out and can fail suddenly. The single wire One you've got should only be around 20-30 bucks. It's kinda like spark plugs, might not be the whole problem but it won't hurt to replace it if its old or original.

As for the tcc, try unplugging the four prong plug on the side, not the two prong speed sensor. If there is a signal trying to lock up the clutch, unplugging it will tell you. If its a problem inside the trans causing it to drag, unplugging it will do nothing. You could also try adjusting the tv cable, just like hotrod said the tv cable will cause a 700r4 to act up.

There are vac operated valves and stuff inside the truck for the HVAC system, disconnect the line that goes into the cab and plug it, if it improves things then the leak is inside.

 

[HotRodPC]

Maybe a vac leak in the power brake booster then. Disconnect it and plug that vac hose. See how the motor runs then.