Wiring smoked...

[mustangsquared]

I killed my 91 a year ago and between the disappointment of the smoke coming from the hood and driving the 06 I never seemed to find the motivation to fix her.

I was "beating" on her chasing the surge demon and came to a stop when I notice smoke from the driver side hood (front) and the temp gauge climbing. I turned around and headed home (luckly only 2 miles away). I got her home and she was still smoking. I didnt bother to pop the hood and look (huge mistake).

I went out today to work on her as she has been calling my name and I miss smoking tires through 2 gears and chirping 3rd..

I cant find any burnt wires, the battery is dead (as expected) and a few vac lines need to be replaced.

My question is:

1) I wired the negative wire for my fan directly to the negative side of the battery instead of the frame.... good idea or bad idea? Its the only thing I can think of. Its the only change I made when I replaced the ground wire to a 4gauge.


I plan to replace the MAP sensor, vac lines, and get a new battery but dont want to kill the battery by mistake.

thanks guys/gals!!

 

[jrichker]

Does the alternator charge OK (dash voltmeter at middle mark or higher at 1000 RPM)?

 

[mustangsquared]

yes, thats the part that messed me up... volt gauge was fine, smoke from driver side hood near headlight, temp gauge climbing like a home sick angel.

 

[jrichker]

The smoke and haywire operation ofthe gauges point ot a bad engine to
body ground. The secondary power ground is between the back of the
intake manifold and the driver's side firewall. It is often missing or
loose. It supplies ground for the alternator, A/C compressor
clutch and other electrical accessories such as the gauges.
Any car that has a 3G or high output current alternator needs
a 4 gauge ground wire running from the block to the chassis
ground where the battery pigtail ground connects.
The 3G has a 130 amp capacity, so you wire the power side
with 4 gauge wire. It stands to reason that the ground side
handles just a much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery & extra 3G
alternator ground wire as described above in paragraph 2. A screwdriver
points to the bolt that is the common ground point.
The battery common ground is a 10 gauge pigtail with the computer ground
attached to it.

Picture courtesy timewarped1972

The computer has its own dedicated power ground that comes off the ground pigtail
on the battery ground wire. Due to it's proximity to the battery, it may become
corroded by acid fumes from the battery.
In 86-90 model cars, it is a black cylinder about 2 1/2" long by 1" diameter with a black/lt green wire.
In 91-95 model cars it is a black cylinder about 2 1/2" long by 1" diameter with a black/white wire.
You'll find it up next to the starter solenoid where the wire goes into the wiring harness.

 

[mustangsquared]

thanks I wil give it a try tomorrow

 

[mustangsquared]

Would a lack of the 4g gorund wire cause my battery to smoke? Still trying to figure out how/why the battery went up.

 

[jrichker]

Would a lack of the 4g gorund wire cause my battery to smoke? Still trying to figure out how/why the battery went up.

The 4 gauge ground is only needed if you have a 3G or other high current output alternator.

However, the secondary ground is necessary. You can use the stock braided strap if it is in good condition.

 

[mustangsquared]

I have a 130 amp alt...3G so I will add the 4g ground wire.

 

[mustangsquared]

4 gauge ground wire added, new battery, MAP sensor replaced. She starts up...takes a second like its thinking... ran fine with a little hunting but I am low on gas, she hasnt run in over a year (yes, I had added fuel stabilizer to her, and octane boost (x3))

Wasnt able to find any smoked wiring up front and the electric fan came on, everything is working.

Now I have another issue... warm engine surge... which is what I was chasing when she died!!

 

[jrichker]

See the "Surging Idle Checklist for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.

 

[mustangsquared]

Thanks,

Had been working off the surge list before the smoke. Down to a couple more options and then it will be onto a new frontier.

 

[jrichker]

Thanks,

Had been working off the surge list before the smoke. Down to a couple more options and then it will be onto a new frontier.

Please post your results. I add to the checklist when someone comes up with a new problem and fix that sounds like it could be a common thing to happen.

Joe R.

 

[mustangsquared]

She idles at 1000rpms fairly nice...gun her and let off fast drops to 1200rpm , then to 950 and then back to 1000rpms...no biggie. But turn her off and try and start her and she starts and then stalls... aurrrgghhhhh!!!!

 

[HISSIN50]

Please post your results. I add to the checklist when someone comes up with a new problem and fix that sounds like it could be a common thing to happen.

Joe R.

Quoted for emphasis and reiteration.

 

[mustangsquared]

WARNING: Dumb question time....

I added the 4g gorund wire by going from the pigtail (computer to battery screw) to my PS pump mounting bolt... but just realized I have alum heads... does that bracket work its way to the block at all or is my ground wire really just taking up space?? Suggestions of another place to mount it?

I have touch this car in 2 years... mt brain hurts from trying to remember everything...used to know it like the back of my hand... cant even find my current tags... which really sucks....

Running 13* BTDC timing...but the dizzy might be a tooth off...I hit as high as 18* by mistake adjusting it without any adverse side effects...but get down to 2* and its stall/non start.

 

[mustangsquared]

so I decided to pull codes...figured she sat for a year and half lets see if anything turns up...

Code 67 and 85

67 clutch neural switch (expected that one)
85 Canister purge solinoid (this caught me off guard)

So I found the canister and the valve... unplugged and the vac line plugged!! (I just had the engine rebuilt 3 years ago and have only put 2000 miles on it so I guess the shop did that...idiots)

I fixed the code 85 and now the surge is gone...initially... restarting it after its hot I get a slight hunting for 20 seconds and then she settles at 1000 rpm's where I have it set becuase of the E303 cam (read here somewhere that you have to bump the idle to 1000 rpms with that "letter" cams as the puter hates them.

 

[jrichker]

See the base idle setting procedure in the "Surging Idle Checklist to set the base idle speed. Then check out the comments in the second post relative to use of Ford letter cams.

 

[mustangsquared]

Thanks, I had removed some of the material in teh IAB to cuase it to "free" flow as in the post but not enough to get the rpms at 1000 without changing the throttle idle screw... I guess tomorrow I open it up a little more and reset the throttle body.

Any advice on the grounding point?

 

[mustangsquared]

ok, now I am confused....

idle set with IAB unplugged, engine hot...1000 rpms... TPS .98volts...timing 13*

idles fine...maybe a movement of 100rpms...barely noticable


Now I plugged the IAB back in and the RPMs went to 1500 rpms and wouldnt come down...unplug it and the rpms drop again. So I flip the IAB upside down...starts up without issue. Idles at 1300 rpms...unplug it and it drops back to 1000rpms... engine is still hot at this point.

Is there something in the computer that always opens the IAB for a certain amount of time regardless of engine temp?

I just disconnected the battery to reset everything in hopes that it will help.

No Codes except the neutral clutch switch.

 

[jrichker]

Use the base idle setting procedure in the second post to the "Surging Idle Checklist" to set the idle as low as you can get it. The IAB can only add airflow, which increases idle speed.