TCCoA Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
Ok, we just did the brakes and now something goes on the engine( I think???) . I was driving fine all the way to work, as I pull into the parking lot, the engine starts to bog, it feels like it is missing real bad, it does not want to move. I was previously throwing a 1131 code, when i scanned it I erased the code, and this has not come on again yet. I tried to unplug the MAF but it still seems to run the same, but I'm not sure how long the engine needs to run with the MAF disconnected. I'm replacing all the spark plugs because they look ugly from running lean. I was even thinking the timing may have jumped, the problem seemed to start at a flick of a switch, and the car has just under 140,000. I also checked the coils and they seem to be ok and had no cracks that i could see. Does anyone have any ideas? I could use the help because I' ve been trying to find the problem for 3 days with no improvements. I also sprayed around the intake to check for vacuum leaks with no success. I'm just scratching my head now:bangwall: Or something like that? Thunderbird 4 LifeV8inWI
Go Bucks!
 

·
Registered
Joined
·
7,758 Posts
Welcome to the boards! :thumbsup:

With the MAF unplugged, your car will run horribly! No power, bogging, etc.

If you unplugged it and it didn’t change anything, the first thing I would do is clean your MAF. Do a search as this has been discussed in detail.

I doubt the 4.6L “jumped time” since the cam and crank position sensors run off tabs on the cam gear and the timing gear on the crank. And if some how they were out of sync, you would know it because your valves would be slamming your pistons. :eek:

The 4.6L is very sensitive to plugs and wires. Do a quick tune-up, which is only plugs and wires, clean the MAF, replace the fuel filter, and double check for vacuum leaks. Those things will 70% of the time fix a lot of drivability problems.

Good luck and let us know how it went. :thumbsup:
 

·
Trumpeter Extraordinaire
Joined
·
2,916 Posts
Here's some info regarding the P1131 code, from the 1994 PC/ED manual:

H40 DTCS 1131, 1151, 1132 AND 1152: DETERMINE CAUSE OF UPSTREAM HO2S(S) NOT SWITCHING. DTCS 1130 AND 1150: HO2S NOT SWITCHING FUEL SYSTEM AT THE ADAPTIVE LIMITS (RICH OR LEAN).

* Diagnostic Trouble Codes (DTCs) 1131 and 1151 indicate the system is correcting RICH for an overly LEAN condition. HO2S voltage less than .45 volts.
* DTCs 1132 and 1152 indicate the system is correcting LEAN for an overly RICH condition. HO2S voltage greater than .45 volts.
* DTCs 1130 and 1150 indicate the fuel control system has reached its maximum compensation for a lean or rich condition.

* Possible Causes:

* Fuel System
o Excessive fuel pressure.
o Leaking fuel injector(s).
o Leaking pressure regulator.
o Low fuel pressure.
o Plugged injector(s).

* Induction System
o Air leaks after MAF.
o Vacuum leaks.
o Restricted air inlet.
o PCV system.

* Base Engine
o Oil over fill.
o Cam timing.
o Compression.

* Ignition
o Coil and secondary side of ignition system.

I read through the testing procedure (rather long test!)...oxygen sensors are what you end up testing after ascertaining all other things listed are ok.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #4
Ok , I did plugs, my wires are on order. We scanned the car with an OBDII computer, found out that the upstrean oxygen sensor has no voltage runnin through it. It also does not change its state and reads 0. So I' m goin to replace that. I have a question on the egr valve. The green wire ALWAYS has vacuum, my dad( a certified mechanic) says that the regulator or solenoid is bad, because it only should have vacuum when you're above 60 mph? I was wondering if anyone else could verify this before I spend the money on the parts. Any info is appreciated!!!!!
 

·
Trumpeter Extraordinaire
Joined
·
2,916 Posts
For what it's worth, here's an article you can read about EGR valve operation: click here. EGR valves shouldn't be open at idle. They're vacuum operated, meaning that if vacuum is applied, the valve will open - if the valve is open, here are some possible causes:

EGR valve stuck open.
EVR solenoid vent plugged or iced.
EVR circuit shorted to GND.
Improper vacuum hose connection.
Plugged/pinched EGR vacuum hose.
Damaged EVR solenoid.
Damaged PCM.

It's possible the DPFE sensor or the EVR solenoid may be the culprit, if the EGR valve is ok. (DPFE: Differential Pressure Feedback EGR; EVR: EGR Vacuum Regulator).
 
1 - 5 of 5 Posts
Top