First Foxbody, Getting Her Running And Back To Her Prime!

[NoTreadDyl]

Hey guys,

I have made a few posts but have been told it would be best to make one thread for the various topics as they all pertain to my car and keeps the progress and information in one place!

The car is registered as an 86 but I am pretty sure it is a 87 GT, 5 speed. So far the modifications are as follows:

-BBK shorty headers
-Flow master exhaust with H-pipe
-Pretty sure it has a 1988 T-Bird Turbo Coupe rear end disk to disk
-MSD ignition coil and rotor.
-K&N air filter
-Short throw shifter
Possibly more I have not yet discovered, none of these mods were conveyed to me when I got the car except the headers, love finding goodies on a new ride!

So far I have done the following:

-Cleaned and reset TPS
-Cleaned the EGR valve and replaced gasket
-By-passed neutral safety switch
-Cleaned and applied dielectric grease to the salt and pepper shakers
-Repaired tail pipe holes
-Cleaned IAC valve
As well as a number of electrical things.

Most recent dump resulted in the following codes: 31, 44, 63, 85, 94.

31- After cleaning the valve the idle returned pretty much to normal, but it is now back to surging and the code is still there. I believe it is either the EVR or EGR sensor, when measuring resistance from the sensor to pin on the ECM it was all over the map, does this mean my sensor is shot?

44, 94, 85- I discovered the purge canister solenoid is missing, the vacuum line from the gas tank is still there and goes to the charcoal can but the vacuum line from the can to the solenoid (also missing) and than intake manifold is gone and has been plugged. I purchased some tubing and the solenoid but have now realized I need a harness for the solenoid that I can only find in America and with the conversion I can't bring myself to pay like $60 bucks when I have more pressing matters. Also the vacuum lines below the EGR vacuum solenoid ( there are two solenoids and each have two lines for a total of 4) are not hooked up, one is vented to the atmosphere so I am assuming this is where codes 44, 95, and 85 are from.

63- After cleaning and re-setting the TPS this code disappeared for a couple weeks but has returned along with a surging idle that can sometimes be fixed by turning off the car which is another indicator its the TPS, is it possible I got a couple more weeks out of her from cleaning but now it is fried? Is the resistance test concrete?

Aside from the codes, I am burning through oil. I push blue smoke intermittently, I would say it smokes less often than it does. Usually when I come to a stop and sometimes on acceleration. It drives very strong thou, cylinder balance test is good so I am hopeful it is something other than rings or bad valve seals. Wouldn't the car not drive so optimally if it were one of these two things? Plugs are greyish.

Lastly, I have confirmed today that both headers are leaking where they bolt to the exhaust pipe adding to the already rich smell and making it rough to even drive with the cab wreaking so bad. Shouldn't they just bolt up, is there supposed to be a gasket or anything? I can see a space, if it can't simply be tightened, does that mean the previous owner skipped a little fab work and it simply does not fit?

Big rant but wanted to put all the information in one place for anyone kind enough to help, so far I have got lots done with the help of this site! So to recap, these are the current issues:

1) Surging idle (intermittent, thought I fixed it 3 or 4 times than keeps coming back after a few days of good idling)
2) Smoking blue from the tail pipes
3) Exhaust leak at the headers

Thanks in advance for any help getting this car back running the way she should!

 

[Davedacarpainter]

Have you gone through @jrichker 's surging idle checklist?

Blue smoke? Oil into the combustion chamber, I would think rings or valve seals. Not much left, possibly a blown head gasket.

Headers need a gasket.

'86 was the last of the four eyed foxes. If you have an areo front, that's '87 on.

 

[Mustang5L5]

The car is registered as an 86 but I am pretty sure it is a 87 GT, 5 speed. So far the modifications are as follows:

86 and 87 are completely different inside and out.

Best way to tell is the VIN

10th character is what you want to look at.
G =1986
H = 1987

 

[General karthief]

I have the wiring for the purg can that hooks the solenoid to the harness on the engine, just have not found it yet.
what would it cost to send it to you from florida?

 

[NoTreadDyl]

86 and 87 are completely different inside and out.

Best way to tell is the VIN

10th character is what you want to look at.
H =1986
I = 1987

I thought in 1980 it started as A and worked its way up, mine is G so I thought that would be 1987, is that incorrect than? If H = 86 than G would = 85 and its definitely not an 85 ?

Daved: Yes I have gone through the surging checklist, as mentioned I had codes for TPS and than got rid of them and now it has returned. And the also explained above is the EGR situation, other than that I have gone through everything on the list except the 02;s, anyone know what number I am looking for when checking the 02;s at the ECM?

If I had blown rings or valve seals wouldn't the car have performance issues not just the smoke ? Might need to get in there and check it out I guess. Also I know the headers have gaskets where they attach to the manifold, but is there supposed to be a gasket in between the single pipe side of the headers that meets the exhaust piping ?

Karthief, I have no idea how much it would cost, I can get the one from LMR for like 60$ by the time it gets here, not sure it would be any cheaper to mail one? Thanks a lot for all the efforts!

 

[Mustang5L5]

I thought in 1980 it started as A and worked its way up, mine is G so I thought that would be 1987, is that incorrect than? If H = 86 than G would = 85 and its definitely not an 85 ?

G is 1986.

I forgot they skipped the letter "I". Too similar to the number 1. O and Q get skipped as well. Here's the correct VIN decode breakdown

http://www.fiveohinfo.com/fox/vin.html#81to93vin

B = 1981
C = 1982
D = 1983
E = 1984
F = 1985
G = 1986
H = 1987
J = 1988
K = 1989
L = 1990
M = 1991
N = 1992
P = 1993

 

[Davedacarpainter]

You won't have a big effect on performance with worn rings or seals.

Sorry, misunderstood the exhaust situation.

 

[NoTreadDyl]

G is 1986.

I forgot they skipped the letter "I". Too similar to the number 1. O and Q get skipped as well. Here's the correct VIN decode breakdown

http://www.fiveohinfo.com/fox/vin.html#81to93vin

B = 1981
C = 1982
D = 1983
E = 1984
F = 1985
G = 1986
H = 1987
J = 1988
K = 1989
L = 1990
M = 1991
N = 1992
P = 1993

Just keeping learning more about this car, mine is registered as a 86 and has G in the VIN but it has an aero front but has the airplane style dash, so I am confused now. Either someone swapped a front clip or the insurance is wrong and its an 87. When I look online it seams I can find pictures that say 86 interior and 87 interior that look almost the same :s

 

[Mustang5L5]

1987 was a complete refresh inside and out. Really need to defer to the VIN here. If the VIN says G, then it was manufactured as a 1986 model.

These cars are frequently swapped around, and not uncommon to see aero noses on 4-eye cars. Lets see some pics and we can help ID what it is you have exactly.

This is a typical 1986 dash

And this is 1987

Outside was completely different as well, and even the 5.0 engine is different. Have you decoded the rest of the VIN? What is the 6th and 7th digit (body style) and what is the 8th digit (engine)

 

[mikestang63]

• check for vacuum leaks
• tighten up the exhaust bots and/or replace gaskets with precy's
• smoking blue from tailpipes- is it at startup or all the time?At startup or decelleration it is likely valve seals and/or guides, if.all the time more likely pistonr ings. How many miles on the motor?

A quick way to check the valve seals/guides is to hook up a vacuum gauge and let it idle. If the gauge rapidly fluctuates then that is an indication they are bad.

You can als do a leak down test to pinpoint the issue . if you hear air out the intake its an intake valve issue, air out the exhaust n then it's an exhaust valve., if you hear it out the dipstick tube or oil fill tube then its the rings. You don't want more than around 15% leakage.


View: https://www.youtube.com/watch?v=ofSiTGeLXvc

 

[NoTreadDyl]

• check for vacuum leaks
• tighten up the exhaust bots and/or replace gaskets with precy's
• smoking blue from tailpipes- is it at startup or all the time?At startup or decelleration it is likely valve seals and/or guides, if.all the time more likely pistonr ings. How many miles on the motor?

A quick way to check the valve seals/guides is to hook up a vacuum gauge and let it idle. If the gauge rapidly fluctuates then that is an indication they are bad.

You can als do a leak down test to pinpoint the issue . if you hear air out the intake its an intake valve issue, air out the exhaust n then it's an exhaust valve., if you hear it out the dipstick tube or oil fill tube then its the rings. You don't want more than around 15% leakage.


View: https://www.youtube.com/watch?v=ofSiTGeLXvc

Thanks, good info. No it does not push smoke on start up, as stated it only smoke sometimes when I come to a stop, I see it coming out the pipes and sometimes on acceleration, never when I start it.

Unknown mileage, apparently the guy who put on the headers also replaced engine components but the kid I got it from wasn't sure what. Dash says somewhere around 220xxx but feels stronger than that and an old timer buddy who's had a shop here for 30 years drove it and agreed it did feel very strong and that it likely did have some engine work done along with the headers.

I have checked for vacuum leaks, as stated I have determined the purge valve solenoid and connecting vacuum lines are gone as well as the 4 lines below the EVR that are not hooked up to anything which from what I have researched are the Thermactor air diverter solenoid and the Thermactor air bypass solenoid. I do not have the smog pump/system hooked up or cats so that explains them being disconnected, I just wonder is there a proper way I can cap them, there is no vacuum present at any of the lines that are vented to the atmosphere? Also since I can't get the last thing I need (purge canister solenoid harness) to hook the charcoal can back up, should I or can I by pass the solenoid and run a vacuum line from the charcoal can to the intake manifold where it is currently plugged or will this make it run to rich?

 

[NoTreadDyl]

1987 was a complete refresh inside and out. Really need to defer to the VIN here. If the VIN says G, then it was manufactured as a 1986 model.

These cars are frequently swapped around, and not uncommon to see aero noses on 4-eye cars. Lets see some pics and we can help ID what it is you have exactly.

This is a typical 1986 dash

And this is 1987

Outside was completely different as well, and even the 5.0 engine is different. Have you decoded the rest of the VIN? What is the 6th and 7th digit (body style) and what is the 8th digit (engine)

I definitely have the 86 dash and I have the G in the vin and its registered as an 86 so I guess someone just did a swap on the front end than? That's to bad!

 

[mikestang63]

If the line off the intake for the cannister is plugged, then it doesn't matter that the line from the tank is venting to the atmosphere, that will not cause a vacuum leak. The other lines you are referring to are probably for the TAD/TAB sensors and regulators for the smog control which I assume are gone and again if the lines are properly capped will not create a vacuum leak.

 

[Mustang5L5]

I definitely have the 86 dash and I have the G in the vin and its registered as an 86 so I guess someone just did a swap on the front end than? That's to bad!

Can always swap it back. 1986 was a popular look, and many guys are into that 4eye nose, myself included.

Just keep in mind the 1986 5.0 EFI was slightly different mechanically than 1987+. You might want to make sure of what you have after you tackle some of these issues.

 

[NoTreadDyl]

If the line off the intake for the cannister is plugged, then it doesn't matter that the line from the tank is venting to the atmosphere, that will not cause a vacuum leak. The other lines you are referring to are probably for the TAD/TAB sensors and regulators for the smog control which I assume are gone and again if the lines are properly capped will not create a vacuum leak.

Correct, those are the lines I am referring to. I'm not really concerned I have a vacuum leak, but still went over all the lines to confirm. The surging problem is either the EGR sensor or EVR, I don't have a vacuum gauge or pump. I made it to measuring resistance from the EGR sensor to the ECM and it was fluctuating, I posted the findings and am still waiting for someone to tell me if I should replace the sensor of if I should test it another way. With regards to running the line from the canister to the manifold, I'm not concerned there is a vacuum leak there, I just thought it make help with reducing the fumes in my garage, but the main reason behind that as discovered yesterday is the leak where the headers mount to the pipes. Even once I get that fixed up, the exhaust itself still smells rich, is this inevitable without the cats and smog pump or am I running to rich?

 

[mikestang63]

sounds like you got it all covered.

 

[NoTreadDyl]

sounds like you got it all covered.

Certainly working on it! But still no one has answered whether or not I should replace my sensor based off my findings. I am going to perform the tests you initially posted, the first one you said to hook up the vacuum gauge and let it idle, where should I hook up the gauge?

Thanks!