Noob Here - Few Questions

Hi

I finally got to drive my new Bronco home last night and besides the shock when I filled up the gas tank I noticed a few things.

I am taking her to a mechanic next week to have a full check up and in the meantime I have been reading like mad to get up to speed on the particular quirks I may encounter.

So here are the basics:

1991 FORD BRONCO
VIN: 1FMEU15H1MLA65731
Body Style: 2 DOOR WAGON/SPORT UTILITY
Engine Size: 5.8L V8 FI
Drivetrain: 4 WHEEL DRIVE
 
She either has 103k or maybe 203k - who knows? She passed safety and emission with flying colors and she feels pretty solid. The previous owner just put a new water pump in. 
There is a lot of rust on underside - but not too much on the body. 
 
Ok here are my questions -
At freeway speeds there is vibration that feels like tires out of balance. (Hoping that's all it is). Is there something else I should look for?
The tach works - then quits working. At freeway speeds it will suddenly drop to zero that pop back up. 
The engine temp gauge reads so low - about at the 1/4 mark that it must not be working properly.
 
There is a slight drag in the tranny but I think its probably what you would expect to see at this age and mileage.
 
I want to follow the so called extreme maintenance schedule to keep the engine - tranny - drive train in good shape. Any suggestions?
 
Thanks!
Michelle

Hi, nice Bronco....

The vibration... could be alignment or balancing...

The Gauge... not very accurate, I added an aftermarket one and mounted it under and behind the ash tray.

If you just purchased it, I would get All the fluids changed. Oil, trans, axle, etc...

Thanks! 

I'll post the results of her checkup next week. 

Every Bronco that i have been in, always vibrates at 70-75 mph, but never really outside that range.

its just how they are, they are made for Power not Speed.

Hi Michelle.., welcome..!

"....there is vibration that feels like tires out of balance. (Hoping that's all it is). Is there something else I should look for?"

Wonder how old those "BIG-O's" are..?

I've had horrible luck with BIG-O tires seperating...., causing a lousy ride.

Don't mention it..., let's see what the inspection crew comes up with..!!

Tach may be just a loose wire.., the temp sending unit may need cleaning or replacement.

"...slight drag in the tranny"

Not sure what this means but would suggest a couple opinions on trannie B/4 changing fluid.

Rumor out there is;  changing fluid in a trannie with issues will make the trannie give up..???

(No 1st. hand experience with this)

yo M,

Tach;

Check fuse. Some become loose bec prev owners insert fuse taps for other aftermarket gadgets

Check fuse electrically for continuity as well as visually

Check for loose wiring connections in engine compartment at coil connector or at instrument cluster.

Inspect instrument cluster printed circuit for damage, poor connections, or open circuits.
CAUTION: Before checking the continuity of any circuit, make sure there is no voltage present in the circuit prior to switching the test equipment to the resistance function to avoid damage to equipment. Refer to the equipment user's manual for additional information.

• Remove instrument cluster and make resistance and voltage checks (using Rotunda 88 Digital Multimeter 105-00053 or equivalent) at 14401 wiring harness connector as follows:Check Pin No. 3 (Connector 1) resistance to chassis ground — should read 1 ohm or less.
• Check Pin No. 10 (Connector 1) resistance to chassis ground — should read 1 ohm or less, if vehicle has 8-cylinder engine. Open circuit if 6-cylinder engine.
• Check Pin No. 9 (Connector 1) resistance to negative terminal of ignition coil should be 1 ohm or less. CAUTION: Make sure multimeter is in the voltage function and not in the resistance function to avoid damage to multimeter.
  
• Connect battery. Key to RUN. Check for +12 volts at Pin No. 13 (Connector 1). Turn ignition OFF. Disconnect battery.
• 

[*]
[*]Pin Number Circuit Circuit Function 1 904 (LG/R) Charge Indicator Lamp 2 932 (GY/W) High Beam Indicator Input 3 57 (BK) Ground 4 450 (DG/LG) Fasten Belt Indicator Input 5 29 (Y/W) Fuel Level Input (with Tachometer) 6 19 (LB/R) Instrument Cluster Illumination Input 7 57 (BK) Ground 8 2 (W/LB) Right Turn Input 9 648 (W/PK) Tachometer Input Signal 10 398 (BK/Y) Tachometer Ground (for 8 Cylinder) 11 784 (LB/BK) Low Range Indicator Input 12 210 (LB) 4x4 Indicator Input 13 640 (R/Y) Power Supply in RUN and START 14 16 (R/LG) Charge Indicator Input
================

Typical High-Speed Vibrations (Above 72 km/h [45 mph])

• rear axle universal joint ****** runout or imbalance
• driveshaft (4602) imbalance
• excessive tire-wheel and drum assembly imbalance
• tire roughness due to high non-uniformity (force variation) or out-of-balance condition
• rear axle pinion gear pitch line runout
• excessive tire and wheel runout
• worn suspension components
• front end accessory vibrations
• exhaust vibration (greatly reduced in exhaust systems de-coupled by a flexible coupling and mounted with blade and block hangers)

At road speed: A vibration is felt in the floorpan or seats with no visible shake, but with an accompanying sound or rumble, buzz, hum, drone or booming noise. Coast with transmission control selector lever in NEUTRAL and engine idling. If vibration is still evident, it may be related to wheels, tires, front disc brake rotors (1125), rear brake drums (1126) wheel hubs (1104), wheel bearings (4000), driveshaft balance, rear axle universal joint ****** runout or transmission balance.

INSPECT TIRES/WHEELS

• Raise vehicle on a frame contact hoist. Inspect tires/wheels for extreme wear or damage, cupping or flat spots

INSPECT WHEEL BEARINGS

• Spin tires by hand to check for wheel bearing roughness. Check wheel bearing end play

Check tire/wheel balance

 MEASURE RUNOUTS

• For each wheel position measure, locate and mark the following:High point of tire/wheel assembly total radial runout.
• High point of wheel radial runout.
• High point of wheel lateral runout.

Record all measurements

ANALYSIS OF RUNOUT MEASUREMENT

• Measurements obtained in A5 must fall within guidelines below.

Do the measurements obtained in A5 fall within specifications listed in Condition 1 in the following chart?
Condition Assembly Total Radial Runout Wheel Radial Runout Wheel Lateral Runout
1 Less Than 1.02mm (0.040 Inch) Less Than 1.14mm (0.045 Inch) Less Than 1.14mm (0.045 Inch) 2 Less Than 1.02mm (0.040 Inch) More Than 1.14mm (0.045 Inch) Less Than 1.14mm (0.045 Inch) 3 Less Than 1.02mm (0.040 Inch) Less Than 1.14mm (0.045 Inch) More Than 1.14mm (0.045 Inch) 4 More Than 1.02mm (0.040 Inch) Less Than 1.14mm (0.045 Inch) Less Than 1.14mm (0.045 Inch)

WHEEL HUB BOLT RUNOUT

• Wheel hub bolt runout can affect wheel runout. Remove wheels and inspect wheel hub bolts.
• Measure wheel hub bolt runout
• 

There are more tests, but I suspect balancing will solve the issue.

GL!

Thanks for the reply!   After driving her to work to day I'm really not sure it its tires. Having experience a few of those on my 88 Camaro (since retired) I know what that feels like and this seems more like what MOJIGGA is talking about. The vibration really starts around 70mph. I set the cruise control at 65 today and the ride was pretty good.  

I learned a little more of her history which is fun. The glove box contained the original owners manual and a few other manuals along with the first registration. From that I was able to find the obituary for the original owner who had her from 91 to 2010. He was a farmer here in Eastern Utah who owned a livestock auction.  His obit said he loved farming, camping and hunting with his family so I am pretty sure that was her main job. That also explains the low miles. 

I also found a invoice for work he had done in 1999 for and R&R intake manifold. Wonder what that was about?

Once the mechanic gives me the results of her checkup I will have a better of idea of where my money will be going first. I am more than happy to put some time and money into keeping her running for as long as possible.

yo,

btw, if tach itself is found faulty, you can swap another tach in-place.

87-96 gauges are only held in by their terminal clips, except the speedo. 80-91 speedos are held in by 2 screws;

Cluster, w/Tach Pic, Back View w/Connector, Terminal & Bulb Identification in 87-91

Source: by Steve

yo, OK, I'm up to 3 replies so far and I think I'll stop...lol

CARFAX REPORT FOR 1fmeu15h1mla65731

http://www.carfax.com/VehicleHistory/p/Report.cfx?partner=DRI_0&vin=1FMEU15H1MLA65731

gOOgled VIN and have many sales ads for it; such as

http://www.murdockhyundai.com/VehicleDetails/used-1991-Ford-Bronco-XLT-Lindon-UT/2024884943

FORD dealer service record summaries, etc. at Ford myford.fordvehicles.com (need VIN) & must register if you haven't already for your other Fords.
 

Thanks for the post. I am thinking I may just have a loose wire in the tach because it jumps back and forth. 

As for the vibration I am going to try this:

At road speed: A vibration is felt in the floorpan or seats with no visible shake, but with an accompanying sound or rumble, buzz, hum, drone or booming noise. Coast with transmission control selector lever in NEUTRAL and engine idling. If vibration is still evident, it may be related to wheels, tires, front disc brake rotors (1125), rear brake drums (1126) wheel hubs (1104), wheel bearings (4000), driveshaft balance, rear axle universal joint ****** runout or transmission balance.

At least when I take her the mechanic I will have a better idea of what to look for. 

I love tires ( I know that sounds strange) and if it is the tires I won't hesitate to replace them. I live on a steep hill and we get lots of snow in the winter. 

I put a set of Nitto Dura Grapplers on my Honda CRV and while they were noisier I loved them.  No changing out tires every six months and they handled the snow and ice better than the Hankook snow tires I had. The CRV was no offroad vehicle however and was just barely tolerable for camping. I can't wait to take the Bronco but it will have to wait until I know she is ready for it. :glare:

I have been doing as much reading here about tires as I can with regard to the Bronco so that when the time comes I know what my options are. 

Anyway thanks again for  making me feel welcome and all the good advice. /emoticons/[email protected] 2x" width="20" height="20" />

Well she went in for her check-up today and it looks like I have one solid Bronco :wub:

The vibration turned out to be the tires. They hadn't been balanced.

The engine and tranny are in great shape.

U Joints, rear axle, springs, front axle etc. all in good shape.

They quoted me  a price for a tune up (about 400.00) but the mechanic said it really wasn't necessary right now. 

I'm still thinking about a drop in K&R filter and a Saginaw power steering pump. 

Oil changes every 3k, 5k? What's a good interval?  

Wish List for Future:

Solid Axle Swap

Saginaw Pump

New Exhaust

Brush Guard - (totally not needed but I love the way they look)

Thanks for the advice you all have given me - I'll keep asking questions if ya don't mind :closedeyes:

Ask away...!!

Don't waste your $$ on any magic air filters..!!  (long story)

What you have is as good as it gets.... (when sealed up , clean, & with the proper filter cartridge)

"Wish List for Future:

Solid Axle Swap  Not a bad idea but  expensive. Usually done for hard-core 4x4'n

Saginaw Pump    Is the factory unit not working..?

New Exhaust       Fresh exhaust = safety & quiet. (a noisy exh. will drive you crazy at hwy. speeds)

Brush Guard - (totally not needed but I love the way they look)"  The right one looks good & they are functional..! /

Drive it a while..., you may find some "priorty" mods/fixes....

Bully Bob said:

Ask away...!!

Don't waste your $$ on any magic air filters..!!  (long story)

What you have is as good as it gets.... (when sealed up , clean, & with the proper filter cartridge)

"Wish List for Future:

Solid Axle Swap  Not a bad idea but  expensive. Usually done for hard-core 4x4'n

Saginaw Pump    Is the factory unit not working..?

New Exhaust       Fresh exhaust = safety & quiet. (a noisy exh. will drive you crazy at hwy. speeds)

Brush Guard - (totally not needed but I love the way they look)"  The right one looks good & they are functional..! /

Drive it a while..., you may find some "priorty" mods/fixes....

Click to expand...

I would not call myself a ******** 4by4 however I do plan on taking her to Moab next February for some off road fun. Mainly it will be camping in the Uintahs and taking a lot of dirt roads. I am glad to hear the solid axle swap will not be necessary for that.

When you say Fresh exhaust - what do you mean? I'm looking to improve gas mileage and general performance. 

The power steering was whining a bit but it's kind of stopped. If and when it does go, I just want to replace it with one that will last.

I'm so used to driving so called "sport utility vehicles" that are built on car bodies that I have to remind myself it really is ok if we get off the pavement. /emoticons/[email protected] 2x" width="20" height="20" />

My immediate do list involves rust removal. Not terribly exciting but at least it's something I can do myself!

yo M, $400.00 for a tune-up?  That  seems high for usual plugs/wires; dist cap & rotor & timing adjust.  Ask mech what he plans to replace/adust.

Prce out the part yourself at Ford's site,

http://www.fordparts.com/

then google Ford part numbers for better $ incl free shippimg (AMAZON, Summitt, JEGS, Adv Auto, etc.)

"When you say Fresh exhaust - what do you mean? I'm looking to improve gas mileage and general performance."

Wellll..,  so many folks do exhaust mods to make noise.., and usually end up with less power, just to gather attention.

"FRESH" for example, a leaky exh. under the hood can be un-healthy @-)   in the trucks cab.    Attending to any cracks, blown gaskets, rot-thru in the tubing, (including the smog stuff) muffler, etc. is a good move.  And, I think Utah checks that equipment at every bi-annual safety inspection.

Carb., cam, & exhaust/headers pretty much go hand-in-hand sooooo, new exhaust won't get you much in performance, if any at all. /emoticons/[email protected] 2x" width="20" height="20" />   (A muffler shop will likely say different)

If the current exhaust is clean & functioning, I wouldn't mess with it W/O doing research.

This is assuming it's all stock & the PO didn't hammer some odd-ball stuff up under there... b-(

These rigs are set-up (or should be) with low end grunt for 4x4'n

It sound like you got a heck of a truck. The Bronco will go pretty much anywhere you are comfortable taking it in its' present configuration. I agree with Bob drive it a bit and stuff will pop up. After you wheel it a bit you will have a much better idea of the things you "really" need.

BTW there is a Broncofest in Moab every year that sounds like a blast, I keep wanting to get to it but work keeps getting in the way.

miesk5 said:

yo M, $400.00 for a tune-up?  That  seems high for usual plugs/wires; dist cap & rotor & timing adjust.  Ask mech what he plans to replace/adust.

Prce out the part yourself at Ford's site,

http://www.fordparts.com/

then google Ford part numbers for better $ incl free shippimg (AMAZON, Summitt, JEGS, Adv Auto, etc.)

Click to expand...

I think you are right, seems a little high to me. 

Regarding the exhaust, I'll have to get under there and have a look at what exactly I have. My guess is it's pretty stock and the PO didn't do any mods that I can see. (Farmer who used it for camping with his family and riding around the farm).

I'm getting familiar with how she sounds and feels so that as time goes by I will know if something sounds or feels off.  

One thing I wish the overdrive button was on the end of the shifter like the new models.  I get on the freeway and sometime forgot to turn it back on.   :glare: I know it won't hurt anything but it's prolly not helping my gas mileage.

Can you tell anything by the readings from the emissions test regarding the state of the exhaust? This is the results from about 2 months ago.

NO...,

However, the rig is runn'n pretty clean.

Those readings are the exhaust gasses..., not the condition of the exhaust hardware.., if I'm reading you correctly.

With clean readings like that.., I wouldn't mess with anything that isn't malfunctioning or broken.. :-B