Ford Mustang Notchback

1991 Ford Mustang Notchback All Part Groups Malfunction When idling Always

Yes I have a 1991 ford mustang 5.0,the car idles up and down when at idle and when driving when the car reaches about 2500 rpm it loses power, but when I shift to 2nd it pulls until I reach 2500 rpm again can you please help me

Hello, Check to see if the air inlet hose clamps are all tight. Look for a vacuum line connection that is disconnected or split. Check the run of the vacuum hose from end to end for condition and collapsing or rotting.

What is your fuel pressure? How old is the fuel filter? Could it be restricted?

What engine do you have please?

Roger

How are you doing here?

Thanks,

Roger

1990 Ford Mustang Notchback Drive Train / Driveline Making Noise When driving Always

Took the car in for an emmisions test to a questionable/stuggling shop where the techs can get under the car, and the car is put on a dyno.
Car passed with flying colours, but now the speedo is ticking/buzzing at all speeds.
Did it once before a couple years ago,but not this bad, and not this loud.
Fix?
I will look under car to look for sabotage, but don't know if the speedo just crapped out after the tires slipped a lot on the wet dyno drums, or ..
What to look for ?

Hi,
Look for a dry or crimped speedo cable. This cable runs from the transmission to the dash. If it is dried out or crimped, a new one is not expensive. Sometimes oiling or straightening the cable may help.

The car had no prob befoer the dyno test, and I have no idea what to lube or what to do it with ,. but abuse of the car is not a possible option?
More choises and other possibilities would go a long way to hel[p me out, as I will get under the car to look at damage if it is there.
More ideas please.

If the cable is dry, I either remove one end, work some motor oil in the cable and blow it with air to force it through. The ideal way is to take both ends off and then it is easier to work the oil through the whole length. The only likely cause for damage at the repair shop would be if the cable got bent, or positioned wrongly.

1989 Ford Mustang Notchback Electrical / Lighting Systems   

My Wifes Mustang turn signals are not working, neither side, but the hazards work, both inside and outside the car. So I know the bulbs and flasher are OK, plus the inside blinkers work too.

I checked all the fuzes, replaced the Flasher unit, replaced the Multi function switch and they still do not work.

Ayn ideas where else I can look, or where I can get a wiring schematic of the turn signal system so I can start tracing wires??

Thanks in advance.

IKE

Use the following link for schematic-- Copy and Paste the link into your Address Bar-

http://autozone.com/images/cds/gif/large/[redacted] 5965.gif

Note- the above schematic shows your system having seperate fuses and flashers for the turn signals. The following schematic shows fuse 5 as the turn signal fuse. The preferred method for testing a fuse is with a test light on both sides of the fuse. Because the back up lights run off this fuse too, confirming the back up lights operate would indicate power is 'on'.

http://autozone.com/images/cds/gif/large/[redacted] 58fb.gif

Thank you Douglas for the schematic and information.

I will check the backup lights!!

I am sure they still work.

I am guessing its probably a bad wire or connector somewhere. They were working fine for the longest, and then they just quit. Both at the same time, but the 4 ways do work. I did repalce the Flasher for the turn signals with a new one and they still did not come on. I also replaced the switch with a replacement one from scrap yard, and still no go.

COY

UPDATE!!!!

I checked the backup lights, they work!!

I checked continuity on ALL LIghts from switch to each light, THERE ARE NO BROKEN WIRES ANY PLACE!!

I even checked the connection between the switch and the turn indicators in the instrument panel!!!

*I am at a loss as to what the problem is!?!?!?!

Any body have any other ideas???

Hello, Where is the flasher that you replaced in your car physically located? What color are the two wires?

Thanks,

Roger

Hi Roger,

The flasher was on a brace under the dash below th instrument panel, the wires are Purple with Orange stripe (2 coming out of 1 side of connector) and a solid light blue one coming out of the other side of connector.

I am sure pulling my hair out over this!!!

Thanks COY

Hi Coy, Do you have power to the flasher on the Pnk/Org wires? It comes from fuse #5 (15 amp).

The Lt Blu wire leaves the flasher and runs to the Hazard Warning Switch. The power leaves the Hazard Warning Switch on a Org/Yel wire and runs to the Turn Signal Switch.

Power leaves the Turn Signal Switch on the Wht/Lt Blu wires if a right turn is selected, or on the Lt Grn/Wht wires if a left turn is selected.

Need a wiring diagram? I'll need your email address.

Roger

Hey Roger,

Thanks for the help.

I do have a schematic, got one emailed the other day and I also have a HAYNES manual.

I am not sure about the power on the lines, I will check this eveing when I get home and let you know.

Thanks

COY

Great! Let me know what you find and we will trace the failure down.

Roger

He Roger,

I am getting 11.3 VDC on the Purple/ Orange side and 11.3 VDC on the Lt Blu Side. I only get this when the ignition is switched on.

But according to the Schematics, Fuze 5 is supposed to be HOT at all times!!

So knowing that I should have power whether or not the ignition is switched on RIGHT?!?!

Thanks for the help.

COY

Coy, That has to be a misprint about Fuse #5 being hot at all times. Ignore that. Turn signals do not work with the key off. We both know that.

Your test is correct. Power passes right through the flasher because there is no ground until the turn signal lever is switched to either a right or left turn.

Turn on the key and turn one of the turn signals on. Do you have power leaving the Hazard Warning Switch on the Org/Yel wire?

If so, does power arrive at the turn Signal switch on the Org/Yel wire?

If so, which turn signal did you select? Left? Does power leave the turn signal switch on the Lt Grn/Wht wire? No? Replace the turn signal switch.

Did you select a right turn? Does power leave the turn signal switch on the Org/Lt Blu wire? No? Replace the turn signal switch.

Roger

Hi Roger,

NO power on Or/Yell wire at all!!

COY

Is the Hazard Warning Switch incorporated in the turn signal switch, or is it located somewhere else? Replace it.

Power is not passing through the hazard switch as it must to power the signals. The hazard switch IS the fault. You've found the cause of no signals!


Roger

But the HAZARDS WORK?!?!

If the hazard switch didn't have any power passing through it would not work would it??

BTW the hazard is on the dash and not incorporated in the steering colum!!

COY

Take a look at your wiring diagram. There are two different power sources to the hazard switch. That's so the flashers can work with the key off. The hazards work without involving the turnsignal switch.

Access the hazard switch. With the key on does power arrive at the switch on the Lt Blu wire? (It should already be there on the Wht/Red wire.)

Turn on either the left or right turn signal. Does power leave the hazard switch on the Org/Yel wire? No?

Try disconnecting the hazard switch. Jumper the Lt Blu wire to the Org/Yel wire. Do your signals work now? Yes? Replace the hazard switch. Retest the signals.

Let me know what happens,

Roger

OK I'll try that when I get home tonight

If that is it I am gonna scream!!!!!

That is one thing I had not thought of!!!

Thanks again.

COY

Go get 'em Coy. You can do it.

Roger

Guess What????

You were right, I got no power on Oran/ Yellow wire out, jumpered from Lt blu to oran/ yellow and turn signals work!!!

Now all I need is a hazard switch!!

Thanks for the help!!!

I will write back and let you know if it does in fact fix the problem!!

COY

Coy, This is not my first rodeo. I knew you would get this fixed if you would take the benefit of my experience and put it in action.

I've always had your success in mind.

Roger

Well thank you roger!!!!

I didn't mean to say you might have been wrong the other day, it was just that I didn't understand how the Hazards could have power, but the switch still be bad!!!

Thanks again!!

COY

I'm excited to help you find the cause. Have you replaced the hazard switch with positive results?

I assure you that I am in no way offended by anything you have said through this process.

When you are ready to accept my answer so that All Parts will pay me just click on the OK TO PAY MECHANIC button.

If you need something further on this question just ask before you click the pay button.

Roger

OK Roger I will make sure I click on the OK button when we are through.

I have not replaced the switch yet, I haven't gotten another one yet.

I am also having a problem finding one locally. May have to order off line or get from dealer.

Thanks again.

COY

Hey Roger,

I can't find a new switch anywhere locally, NOT EVEN at DEALER. Ford does not make switch anymore.

I just bypassed the switch by connecting or/yell wire to lt Blu one and everything works now!!!

Thanks for your help!!!

COY

1988 Ford Mustang Notchback All Part Groups   

went from a 70mm throttle body to 75mm now car surges bad from the idle checked ICA the EGR the Throttle Position senser set at 9.4 no vac leaks idles when ICA is unplugged DSS 347 30LBS 75 AIR 555/565 COMP AFR 185 timming set at 15 gun 33 total

A bad fuel pressure regulator can cause surging. Have you verified fuel pressure?

The car has a new bbk fuel pressure regular and its set at 42 psi the car ran fine with the 70mm throttle body on it when I weht to the 75 mm the car surges at the idle dont know if I have to get a new computer chip burned for the 75 mm throttle body when the first start up its fine when it warms up the it begans to surge at idle

1987 Ford Mustang Notchback Electrical / Lighting Systems   

When driving the headlights go out. You can shut the switch off and turn back on and they will come back on. What do you suggest?? Could this be the relay or a switch?? Where is relay located if this is the problem?

More likely the switch, relatively common problem.

1985 Ford Mustang Notchback Windows / Glass Leaking  

I have a 85 lx 5.0 coupe,the heater core is disconnected no water running to it.Every time it rains my passenger side floor gets soaked.I had windshild checked at glass co. No Leak.I pulled back carpet during last rain,water coming form behind dashboard,it appears the firewall is leaking somewhere below the cowl.Ever seen this problem,do you have any suggestions. Thanks

Check your drains on each side of your car in front of the windshield where the fenders attach to the body in front of the doors. If that plugs up, the water will leak inside through A body plug or wireing hole.