11-20: mechanic pulls codes 33,41,49,59,62,67. Replaces egr,evp sensor,cleans injectors, cleared codes....I got it home and

12-2: changed o2 sensor, plugs, wires. Engine light still coming on so I figure , its the trans...

12-4: Trans shop putting in sensor pack and sensor...he scoped it and said good ole 33 and 41 were the codes still coming up and says those codes are ego and tps codes...not egr or o2 sensor

Any suggestions before I drain what's left of my money on mechanic#1? (Brian's Auto Center Beaumont, Texas)

I hate to say it on the Ford Board, But, I miss my old Dodge with its trusty carb, that people still could work on.

1990 F-150, 351 EFI
117,000

 

[font size="1" color="#FF0000"]LAST EDITED ON 04-Dec-00 AT 08:46 PM (EST)[/font][p]tps stands for throttle position sensor, its located on the throttle body, buy the part and replace it youself, dont let a mechanic screw you over. as for the other code that may be your catylitic converter acting up. i dont know.

John Floyd
South Mills,NC
'86 F150 2wd 300 6
Crane Cam 260/272
stock manifolds, w/ staight pipe

 

Ok , I went thru the Pinpoint test for Code 33 ( Continuous Memory ) It indicated the egr valve did not open when it should have . Possible cause are obstructed or cracked vacuum line to the egr valve , Open circuit in the Evr solenoid or a faulty egr valve . Check that the egr valve opens & holds vacuum . Also make sure the vacuum line to the egr valve is connected to both the egr & its vacuum solenoid .

Code 41 ( Continuous Memory ) Indicates that the O2 Sensor is not switching during closed looped . Since the O2 sensor was replaced recently its possible you have an intake leak . Is the idle higher than normal ? Any unmetered air will cause problems with the O2 Sensor . Also Check the fuel pressure .

 

Code 41 is the EGO (Exhaust Gas Oxygen) sensor reads a lean condition. But code 33 is the EGR valve position sensor indicates that the EGR valve is not opening or is sticking. This could cause a lean condition in your truck if the EEC is trying to adjust for it. I am not sure where the mechanic came up with code 33 being the TPS but I would try the EGR valve position sensor first. Last time I replaced one about 2 years ago it cost 30 dollars. not too bad considering the TPS was 70 something. If you are standing in the front of the truck looking at the motor the EGR valve is mounted off to the left of the upper intake manifold on the front of the engine. On my 351 it tapped into the exhaust manifold on the passenger side but I think on the 302 it taps into a manifold that runs along the back side of the heads. On the top of this valve is a small gray piece with an electrical connector on it. This is the EGR valve position sensor. Hope this helps

Brad Godkin
1986 F350 CC/SRW
6.9liter/C6

 

I just remembered something about the egr system on my truck! You said it taps into the manifold between the two heads? Mine doesn't even tap into the exhaust system. Mine just runs back into the lower intake. Is there an exhaust crossover on the EFI 302's or is this something special ford did to some of them.

The only place anything ties into the manifold at the back of the heads, is the pipe that comes off of the AIR pump.

Ok, this is getting wierder by the minute, Is this the reason my truck could not be running right?


"You can always tell a Chevy owner, You just can't tell them very much."

 

I might be wrong about the EGR on a 302. i haven't owned a EFI 302. The only experience I have with them is working on friends trucks. Know that you mention it I think the AIR pump does hook in there. Is there a steel tube running along the passenger side of the engine that hooks from the back of the heads to a rubber hose up near the front of the block On yours? I'll look at a friend of mines truck tonight at work and see where his hooks into. I think I was wrong on that.

Brad Godkin
1986 F350 CC/SRW
6.9liter/C6

 

Thank ya'll for all the input!!

Brought it back to mechanic today....it was either spend more money for him to scratch his head and play "try a part", or a 1" piece of black tape...went with the tape. Truck is now running fine, but the %&**$! light stays on...may try someone else after Christmas if I win the Lotto.

thanks again

 

Welcome to the exciting & expensive world of Ford EFI maintenance! You are now part of the "brotherhood" of those who look at their engines and scratch their heads and mumble to themselves "what were these idiots smoking?"




"You can always tell a Chevy owner, You just can't tell them very much."

 

Hey Hotrod your right. The manifold on the back of the heads goes to the AIR pump. don't I feel dumb. I would definatly try thr EGR valve position sensor though. Sorry for the confusion.

Brad Godkin
1986 F350 CC/SRW
6.9liter/C6

 

The 41 error indicates a lean condition. If the O2 sensor is new, then any unmetered air will cause this condition, i.e. vacuum leak, intake leak (intake manifold gasket?), exhaust leak before O2 sensor (cracked manifold?). The fact that rebel yell also gets error 33 (EGR did not open intermittently) points to a tiny vacuum leak that leads the EGR valve to belive the engine is idling and it closes.

 

Bgodkin,

Hey man don't worry about it. I am confused all the time with this goofy truck. After all Most of it I built! But my thing is, I thought that the EGR was supposed to be tied into the exhaust too. Not back into the lower intake, like it is. Talk about Fords engineers doing something strange.


[link:www.geocities.com/hotrodford_88/|Hotrodford_88's Webpage]

[link:www.geocities.com/westlake_vfd/Westlake.html|Westlake VFD Website]

 

>as far as the egr valve goes buy a vacuum test kit (22.00) and hook it up to the egr and watch the diafram when you vacuum the tip. your engine should change rpm when it opens. the exaust of the egr goes in a steel tube to the exaust pipe. check your engine vacuum with the test kit too.also you should check the map sensor and most importantly replace the pcv valve. a bad pcv valve can really screw up an engine in this emissions paranoid world. good luck. remember chasing codes is sometimes like chasing a ghost.
>
>
>
>
>
>
>
>
>11-20: mechanic pulls codes 33,41,49,59,62,67. Replaces
>egr,evp sensor,cleans injectors, cleared codes....I
>got it home and
>
>12-2: changed o2 sensor, plugs, wires.
>Engine light still coming on
>so I figure , its
>the trans...
>
>12-4: Trans shop putting in sensor
>pack and sensor...he scoped it
>and said good ole 33
>and 41 were the codes
>still coming up and says
>those codes are ego and
>tps codes...not egr or o2
>sensor
>
>Any suggestions before I drain what's
>left of my money on
>mechanic#1? (Brian's Auto Center Beaumont,
>Texas)
>
>I hate to say it on
>the Ford Board, But, I
>miss my old Dodge with
>its trusty carb, that people
>still could work on.
>
>
>
>
> 1990
>F-150, 351 EFI
>
>
>
> 117,000
>

 

I hate to say this but, the egr tube on my 88 efi 302, doesn't hook into the exhaust pipe anywhere. It runs back under the upper intake and is tapped into the lower intake. This is factory, I have not changed anything on the emissions setup on this truck. That's why I don't think the egr serves any purpose on this truck, because I can't see where the exhaust would be recirculated anywhere.



[link:www.geocities.com/hotrodford_88/|Hotrodford_88's Webpage]

[link:www.geocities.com/westlake_vfd/Westlake.html|Westlake VFD Website]

 

When I took it off the other day my EGR valve had a tiny plastic hose on the top that goes into the vacuum system. Isn't that where the exhaust comes back in (via the hose in the back of the engine from the exhaust pipe)?

 

My dad remembered something the other day when I brought up this subject to him. After I thought about it I remembered the same thing. My engine came out of a plant truck, so it was pretty badly carboned up. I mean to the point where I had to take the heads off and use a screwdriver to pick the carbon out of the crosovers in the heads. My lower intake has an exhaust crossover built into it, that is where the exhaust is piped in. Mine ran so much better after cleaning out all of that nastiness it is unreal. I am probably going to pull the throtle body off this weekend and clean it out. The throttle plates are sticking closed, when you press on the pedal after it has set for a little while, you can feel the plates break loose.


[link:www.geocities.com/hotrodford_88/|Hotrodford_88's Webpage]

[link:www.geocities.com/westlake_vfd/Westlake.html|Westlake VFD Website]