just bought my first mustang, have a few questions already!

jzauner

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okay, update time.

I've spent the last week buffing out some of the paint since I was waiting on all of the fuel stuff to come in.

I got the new gas tank (it was definitely worth replacing), put the fuel pump, fuel filter, etc on. When I went to raise it back up, my jack broke (of course...). I was able to raise it most of the way up with some paint cans and I had laying around. The drivers side strap hooked up alright (just loosely bolted on, haven't tightened it yet, but I am not able to get the drivers side up. I am about to go head out to get a new jack, but I thought I would ask first if there are any things it likes to catch on or tricks to get it bolted up into place. I know you guys are much more knowledgable as I've only owned a mustang for about two weeks now.

Fingers crossed this will turn it over!
 
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91TwighlightGT

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It is always a battle from my experience. Those straps bend a bit, and sometimes get bent while removing the tank. Don’t be afraid to bend them a bit going back into place.

It can be hard to get the bolt going, but you will get it with enough perseverance. I don’t recall the tank getting caught or anything like that.
 

jzauner

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That’s what i assumed. Just wanted to make sure there wasn’t a trick with the fuel lines before I went back at it.

The filler tank gasket and the vapor vent gasket were the consistency of play dough. Glad I went and replaced it all.

Busy day tomorrow, but I will find time to get this completed. How much gas is good to test it out? Maybe a gallon or two?
 

jzauner

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Well, she started right up. Imagine what having some fuel pressure will do! Next is to look at the transmission and brakes. I’ll also replace the timing belt and get it timed up. I’m getting more excited!
 
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65ShelbyClone

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I'd just make sure the brakes work, check all the fluids, and then take it around the block to see how the trans works. It's not likely IMO that the timing belt is in imminent danger of breaking. When you do replace it, I suggest getting a Gates or Goodyear belt+tensioner kit and replacing both parts. It'll still be pretty cheap.
 

jzauner

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Update number 2 today. It has been an exciting day so far! First of all, thank you all for your guidance in getting the engine up and running! It is throwing a check engine code, so I will have to see what that is about.

Two questions for you guys now:

1- the transmission goes forward in reverse, neutral, drive, etc. It does not in park. I assume this is just a linkage adjustment, but I haven't really messed with automatic transmissions much in my day, so I thought I would ask the hive mind before I start adjusting stuff. Which way do you go about doing this? set transmission and shifter in neutral, then reconnect? or drive?

2- the fuel gauge is still showing empty. I put about 4 gallons of gas in the tank today, so it should be higher. It didn't work with the old tank, which did have some gas as well. But with a new sending unit, it is still bad. Is there a handy test like all of the ones listed on the "crank but won't start" list to see what is the issue here?
 

91TwighlightGT

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It is likely a bad fuel gauge. There is also a slosh module that often goes bad... apparently 91 was particularly bad for it for some reason.

https://lmr.com/item/LRS-10849/90-93-Mustang-Instrument-Voltage-Regulator

Here is the fuel gauge diagnostic that Jrichter posts from time to time...

Fuel Quantity gauge troubleshooting 87-93 Mustangs




The red/yellow wire (power supply to gauge & sender) should have 12 volts when the ignition is in the start or Run position.

Troubleshooting the gauge and sender circuit:
Since the sender uses a variable resistor, sum the resistor values of 22 Ohms (empty value) & 145 Ohms (full value). That gets you 167, which you divide by 2: that gets you 83.5. So in theory, 83.5 ohms is 1/2 full. A trip to Radio Shack for the closest combination of resistors to make 83.5 ohms gets you one 68 Ohm (Catalog #: 271-1106) + one 15 Ohm (Catalog #: 271-1102) for a total of 83 Ohms at the cost of $2 plus tax. Wire the resistors in series to make a resistor pack and cover it with heat shrink tubing or electrical tape. The 83 Ohms is close enough to the 83.5 Ohm figure that it shouldn't matter. Disconnect the electrical connector shown in your for the tank sender unit. Connect one end of the resistor pack to the yellow/white wire on the body side fuel sender electrical connector and the other end of the resistor pack to ground. Make sure nothing is touching that isn't supposed to and turn the ignition switch to Run. If I am correct, the fuel gauge will read 1/2 full, or very close to it. If it does not, then the odds are that the gauge or anti-slosh unit are bad.

How and why the test works…
Most of the fuel gauge failures give a stuck on full or stuck on empty as a problem symptom. Using a resistor combination that mimics 1/2 tank allows you to decide if the gauge and anti-slosh module are the problem source.

If the gauge reads about 1/2 tank with the resistor combination, that points to the sender as being the culprit.

If the gauge reads full or empty with the resistor pack in place of the sender, then the gauge or anti-slosh module is at fault.

Fuel gauge sender testing and replacement
The next steps require dropping the fuel tank and removal of the fuel level sender. Here are some useful tips...

I have done the tank removal three times, and the main issues are getting the car up on jack stands and getting the gas out of the tank. DO NOT try to do this job without jack stands. Becoming a pancake is not part of the repair process.

Pumping out the old gas:
If the old pump still works, you can use it to pump the tank out.
1.) Separate the pressure line (the one with the Schrader valve on it) using the fuel line tools.
Look in the A/C repair section for the fuel line tools. They look like little plastic top hats. You will need the 1/2" & 5/8" ones. The hat shaped section goes on facing the large part of the coupling. Then you press hard on the brim until it forces the sleeve into the coupling and releases the spring. You may need someone to pull on the line while you press on the coupling.



Use a piece of garden hose to run from the pressure line to your bucket or gas can. Make sure it is as leak proof as you can make it. Fire and explosion are not part of the repair process...

2.) Jumper the fuel pump test point to ground.


Turn the ignition switch to the Run position. the fuel pump will pump the tank almost dry unless the battery runs down first.

Some 5 gallon paint pails lined with garbage bags are good to hold the gas. The garbage bags provide a clean liner for the pails and keep the loose trash out of the gas so you can reuse it. If you decide to use a siphon, a piece of 1/2" garden hose stuck down the filler neck will siphon all but a gallon or so of the gas.

Remove the filler neck bolts and put them in a zip bag. Disconnect the supply & return lines by removing the plastic clips from the metal tubing. If you damage the clips, you can get new ones form the auto part store for just a few dollars. I have used tie-wraps, but that is not the best choice. Then you remove the two 9/16" nuts that hold the T bolts to the straps. Put the nuts in the zip bag with the filler bolts. Pull the plastic shield down and away from the tank. Once the tank drops a little bit you can disconnect the wiring for the pump & fuel quantity sender.

The fuel gauge sender assembly comes out by removing a large metal ring that unscrews from the tank. There is a separate mounting/access plate for the fuel pump and fuel gage. You are supposed to use a brass punch to tap on the ring so that you don't make sparks. Look closely at the rubber O ring gasket when you remove the fuel gauge sender.
When you install the metal ring that holds the sender in place, watch out for the gasket O ring. Some RTV may be helpful if the ring is not in excellent condition.

The tank to filler pipe seal is a large rubber grommet. Inspect it for hardening, tears and damage. At $20 from the Ford dealer, it might be a good idea to replace it.

I used a floor jack to help lift the tank back in place. You may find that it is the only time you really can make good use of a helper.

All resistance measurements should be made with the power off.

Note from bstrd86 - 86 and older fuel tank sender units are 73 ohms empty, 8-12 ohms full.


The yellow/white wire will show a voltage that varies with the movement of the float on the sender unit. To test the sender, set your Ohmmeter or DVM on low Ohms. Then disconnect the sender and connect the Ohmmeter or DVM to the yellow/white and black wires from the sender unit. Move the float arm while watching the Ohmmeter or DVM. You should see the reading change from 22 to 145 ohms +/- 10%.

If the Ohmmeter or DVM resistance readings are way off, replace the tank sender unit.

Use extreme caution if you do the next step. Fumes from the gas tank can easily ignite and cause a fire or explosion.
With the sender unit out of the tank and connected to the body wiring harness, turn the ignition switch to the Run position. Move the float arm and the fuel gauge indicator should move. If you are very careful, you can use a pair of safety pins inserted in the connector for the yellow/white and black wires to measure the voltage as you move the float arm. The voltage will change, but I have no specs for what it should be.
Do not short the safety pins together or to ground. If you do, you may damage the anti-slosh module or crate a spark. A spark with the fuel tank open could cause a fire or an explosion.

If the voltage does not change and the tanks sender passed the resistance tests, the anti-slosh module or gauge is bad.

Anti-Slosh module pictures courtesy of Saleen0679

 

jzauner

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Alright, so I crawled under and adjusted the transmission linkage. No dice. I think it was actually in the right spot to begin with. Just something internal gone wrong. Still goes forward in all gears, though a bit more sluggish than it was before. It is throwing out a check engine code, so I'll need to check on that as well. I'll keep you guys updated.

Here are the things I have noticed if that helps anyone out with a diagnosis:
Reverse still turns on the reverse lights.
Car is still pushable in both directions when in neutral (when we pushed it up on the trailer), however that was tough to do. Tires were a little low, and the angles sucked (garage was angled downhill and trailer was quite a bit uphill). Also, could have been some rust as well. But when the transmission is shifted into neutral with engine on, it goes forward.
 
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91TwighlightGT

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You have broken internal parts in the transmission. There is no way to repair it without pulling the transmission apart. I’d recommend a rebuild, or a T-5 swap.
 

jzauner

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That's what I figured. But I always like to ask before I jump to conclusions and throw a ton of money out.

I did find a AOD for free from a 91. I'll be picking that up this week and try to throw it in this weekend. The guy removed it for a 5.0/T5 swap, so he said it all works great. If that doesn't work, I have a lead on a T5 for a 4 cylinder with everything needed.
 

91TwighlightGT

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Be advised that if an AOD swap is feasible, or if you go to a T-5, then you will need the Driveshaft as well. The A4LD used a different length shaft than all other mustangs.
 

jzauner

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for a 91, are there different possible automatic transmissions? I assume that since it came from a 91 4 cylinder, it should match. I am going to shoot for the AOD for two reasons:
1-free
2-easier than the swap, and the guy said it works.

Thanks for the heads up on the drive shaft. I had no idea
 

91TwighlightGT

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The 5.0l cars have the AOD. The 2.3l has A4LD which is different. I don’t know if the AOD can be put behind the 2.3l and work properly.

EDIT: If it is another 2.3l car then it is an A4LD and should bolt right in.
 

jzauner

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So I will be picking up the transmission today and look at installing it today or tomorrow. I know that when you disconnect a driveshaft, you mark it so you put it back on correctly. However, do you do that when replacing the transmission? What would you line it up with?
 

General karthief

wonder how much it would cost to ship you a pair
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At the rearend, mark it so it's bolted back in the same place, if the front is a bolt on do it there too but your using a different trans and it's a slip in so no need. If your drive shaft is of unknown age I would replace u joints and have it balanced too.
 

jzauner

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Driveshaft is a slip in on the front end but bolt on the back. I marked that one for sure. I got the transmission (bellhousing) unbolted except for one. The one on the top passenger side (that the tranny dipstick is bolted on to). I can’t seem to get leverage to break that bolt free. I’ve tried from up top, but can’t seem to get a wrench or breaker bar on the bolt. I can’t get my fat arms up from the bottom either.

Is there something painfully obvious I am missing? I had a friend over who is a mechanic over and he said he would bring a long 13mm wrench and a locking flex head ratchet and try that. Just didn’t know if there was a magical combination of tools or a certain angle that works better. And you guys always seem to know the answers!