Engine Oil, Smoke, Fire And Brimstone.


New Member
Sep 9, 2017
Ok, not really the last two.

Vehicle Information: 1993 5.0 litre in a 1990 Fox, A9L running GUFB strat on unknown def, aftermarket tb but not aftermarket MAF, knockoff cobra intake I think and possibly stock injectors.

Hope this isn't the wrong board, suck at forums. I'll move it if needed.

Here goes: Today has been possibly the worst day ever. I drive all day and it's great, as soon as I pull into the driveway the car coughs up blood and conks out. I've called four local mechanics and they all won't give me the full story (because they want me to come in and pay for it I'm sure) so heres what I got.. hoping you guys can help...

Issue: Car idles rough, sometimes dies, feels like a misfire, will rev high just fine, and drive, but just an overall shakiness that wasn't there before. Smoke and oil from exhaust.

Background: have been driving this car for 43 miles. Engine has 90k, tranny 265k. When I bought it it ran just fine on all 8 cylinders, shifted great, revved fine, that pinging issue I posted about[on another forum] turned out (probably) to be a shifter rattle since its metal on metal and if I put my hand lightly on the shifter it doesn't vibrate nearly as much. Local mechanic took it for a drive and agreed.

Changes since then: Disconnected an aftermarket AFR meter. Might have been wideband since it had like 20 markings, but no numbers, so who knows. It was disconnected from power, and ground. There was a third wire (purple) that was likely an input but was never hooked up in the first place. I also reconnected the previously blocked off EGR cooling doohicky. It's the two hoses in fig 1 (that's not my car though) that go in and out of the TB. Removed climate control wiring and put a screw into the suck-y part of the green connector behind the dial where you select where the air comes from. My car has no AC so I just got rid of it. I put in the screw because it's under vacuum and seemed to make a hissing sound without the blockage. Drove fine like that for a day.

Symptoms and Evidence: Assuming misfire because a) feels waaaay shakier and jerkier than it did and b) sounds like it in the exhaust. Possibly has something to do with that BAMA chip with unknown tunes because when I peg the throttle it seems to smooth out just a bit (open loop?), sticks at a higher idle when I let off, but then it will fall back down to the standard idle and sound like hot garbage again, as you can see in the revving video. The exhaust is separate, no H or X pipe stuff, one header/tube per tip or so it looks like, and both tips left and right let off a little smoke and a little oil under varying conditions. I say oil because it is brown, slimy, not sweet, smells like oil not gas, and stained my garage. However, the left pipe leaves more oil marks and the right pipe is more smoky, except under load (clutch engaged) when the left pipe is also plenty smoky. This smoke is white and faint, you'll have to look hard in the video. Holding a rag up to the exhaust shows little drops of oil being flung, and revving it seems to make it cough and spit oil everywhere. Dipstick measurement was taken after shutting off engine, it was removed, wiped, inserted, removed, and then I took the picture. When initially removed, it was a similar color, but had slightly more bubbling (the pic only shows one bubble). It is still the same color as it was when I bought it. Slight ticking noise under the hood seeming to come from the throttle body. I tried to pull codes but the OBD I scanner didn't work, and the manual code dump didn't work (CEL never flashed, maybe bulb is dead or the CEL light was painted over. Dash is glued closed). Spark plugs look fine on left bank cylinder 1, LB2/3/4 look fine but were a little wet with what honestly felt like oil, and wiping it on cloth it looked like oil. Haven't checked right bank, as it doesn't seem to smoke or spit oil as much. White smoke that has been mentioned a couple times is very faint but definitely there. I'd think if the smoke is burning oil it would get worse as the engine warms up, all this info is given on a cold engine, except when it died. Obviously it was hot when it died as I pulled in.

The pictures are as follows: the one with three cloths is [left cloth is scrubbed from the inside of the left pipe, right cloth is scrubbed from the inside of right pipe, center cloth was held up to left exhaust tip about an inch or two from the opening at idle.] the one with the two marks is obvious, the one of the engine bay is not my car but is what i was talking about earlier in my post. See the images here(Be sure to read image descriptions.): View: https://imgur.com/a/CLtsF
Videos here: View: https://vimeo.com/233151939
View: https://vimeo.com/233151925

I've provided as much evidence as I can, I will provide more if needed.
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StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
Dublin GA
Cylinder balance test: use this to find dead or weak cylinders:

Revised 09-Sep-2017 Added reminder to write down the stored codes and engine running codes.

The computer has a cylinder balance test that helps locate cylinders with low power output. You’ll need to dump the codes out of the computer and make sure that you have the A/C off, clutch depressed to the floor and the transmission in neutral. Fail to do this and you can’t do the engine running dump codes test that allows you to do the cylinder balance test.

Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

Be sure to turn off the A/C, have the clutch depressed to the floor, and put the transmission in neutral when dumping the codes. Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.

Here's how to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.



If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.


The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.


The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.
This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and drivability problems

Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Dumping the Engine Running codes: The procedure is the same, you dump the codes and then you start the engine with the test jumper in place. Be sure the A/C is off, clutch depressed to the floor and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Your 86-88 5.0 won't have a working Check Engine Light, so you'll need a test light.
See AutoZone Part Number: 25886 , $10

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see www.midwayautosupply.com/Equus-Digital-Ford-Code-Reader/dp/B000EW0KHW Equus - Digital Ford Code Reader 3145.
It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $22-$36.
Order it at Walmart for a better price and free shipping

Write down the codes that the computer outputs since they will give you information on problems that are stored in the computer's memory

Cylinder balance test

If you have idle or IAC/IAB problems and the engine will not idle on its own without mechanically adjusting the base idle speed above 625-750 RPM, this test will fail with random cylinders pointed out every time it runs. The IAC/IAB must be capable of controlling the engine speed to run in the 1300-1500 RPM range. Playing with the base idle speed by adjusting it upwards will not work, the computer has to be able to control the engine speed using the IAC/IAB.

Warm the car's engine up to normal operating temperature. With the test jumper in test position, start the engine and let it stabilize. It should flash a 10 and then a 4 and maybe an 11. If no 11, then there are other codes that will be dumped.

Write down the codes that the computer outputs since they will give you information that the computer found when it is running. Theses are often different from the stored codes.

One of the first tests it does is to open the EGR all the way, this will cause the engine to stumble and almost die. If the engine dies here then you have EGR problems.
To start the cylinder balance test, briefly floor the accelerator past 2500 RPM and let off the accelerator. The engine will stabilize at about 1300-1450 RPM and the cut off the fuel injectors one at a time. The engine speed will drop briefly and the computer will turn the fuel injector for the cylinder under test back on. Then it starts the process for the next cylinder. When it has sequenced through all 8 injectors, it will flash 9 for everything OK, or the number of the failing cylinder such as 2 for cylinder #2. Quickly pressing the throttle again up to 2500 RPM’s will cause the test to re-run with smaller qualifying figures.
Do it a third time, and if the same cylinder shows up, the cylinder is weak and isn’t putting out power like it should. See the Chilton’s Shop manual for the complete test procedure

See View: https://www.youtube.com/watch?v=HDXrkKS4jTE
for a visual tour through the process. There is no voice narration so you have to listen carefully for the engine sounds. I posted the link for the benefit of Stangnet members who had questions about how to do a cylinder balance test. I do not own that video and I am not the creator.

Do a compression test on all the cylinders.
Take special note of any cylinder that shows up as weak in the cylinder balance test. Low compression on one of these cylinders rules out the injectors as being the most likely cause of the problem. Look at cylinders that fail the cylinder balance test but have good compression. These cylinders either have a bad injector, bad spark plug or spark plug wire. Move the wire and then the spark plug to another cylinder and run the cylinder balance test again. If it follows the moved wire or spark plug, you have found the problem. If the same cylinder fails the test again, the injector is bad. If different cylinders fail the cylinder balance test, you have ignition problems or wiring problems in the 10 pin black & white electrical connectors located by the EGR.

How to do a compression test:
Only use a compression tester with a screw in adapter for the spark plug hole. The other type leaks too much to get an accurate reading. Your local auto parts store may have a compression tester to rent/loan. If you do mechanic work on your own car on a regular basis, it would be a good tool to add to your collection.

With the engine warmed up, remove all spark plugs and prop the throttle wide open with a plastic screwdriver handle between the throttle butterfly and the throttle housing. Crank the engine until it the gage reading stops increasing. On a cold engine, it will be hard to tell what's good & what's not. Some of the recent posts have numbers ranging from 140-170 PSI. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn. There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.

I generally use a big screwdriver handle stuck in the TB between the butterfly and the TB to prop the throttle open. The plastic is soft enough that it won't damage anything and won't get sucked down the intake either.

A battery charger (not the trickle type) is a good thing to have if you haven't driven the car lately or if you have any doubts about the battery's health. Connect it up while you are cranking the engine and it will help keep the starter cranking at a consistent speed from the first cylinder tested to the last cylinder.[/b]
Last edited:

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
polk county florida
Do a compression test
What does your coolant look like?
jrichker post same time so there are instuctions on pulling codes.
Do you have any blue smoke (blowby) coming from oil filler or dip stick tube?


New Member
Sep 9, 2017
Thanks for the reply. I'll try using the 88-86 or whatever the older method is to pull codes since my CEL seems to be inop. Coolant is low but looks fine. Low because the overflow tank fell off so every time it heats up it pees on my driveway. Working to fix that so I can actually verify if my engine eats coolant or not. Tomorrow, I'll rent a comp tester and do that and check for blowby on tube or filler with the cap open however with the caps closed, nothing was coming out.

For comp testing, since I work alone I assume I can just screw it in, go inside and floor it while I crank. No gas will come out since it engages flood clear on the injectors or so I've heard.


New Member
Sep 9, 2017
they still use the old solenoid? wow. used that trick on my '66 lol.

This car has a bunch of tunes and even when it ran well the idle was like 800, more than jricker said was good.. should i unplug the tuner and see if it runs stock? if it does.. where do I even start?

I'm thinking comp test the way you said, if thats all good try and run it stock tune, if thats good, fix the idle, if thats good, and the misfire is still happening, do the balance test..

Or I could do it the old fashioned way (Unplugging each cyl from dizzy cap and listening) and avoid having to fix the idle and change the tune to stock in order to run the balance test