1989 Ford Lariat 4x4 pickup wont sip gas...

All off topic conversation held here. Have fun and play nice. =)

Moderators: Bookworm, starkruzr, MrFireDragon, PrettyPrincess, Wapsi

User avatar
TazManiac
Posts: 3701
Joined: Fri Nov 29, 2013 6:53 pm

1989 Ford Lariat 4x4 pickup wont sip gas...

Post by TazManiac »

in my head, I call it a Loredo, but anyway...

Dude called me over to help w/ a 'new to him' pickup truck: he said the following-

"I replaced the Alternator and the dashboard Alt Meter doesn't show a charging condition so..."

Preconditions;

- Previous owner might have, at some time long ago, did a motor rebuild/replacemnt. (eh)

- Truck has a Dual gas Tank system, complete w/ potentially problematic inter-tank valve system that, when it goes wrong, will overfill one tank with the contents of the other...

- In General, this is a Thirty year old motor vehicle.

Dude had it parked in the neighbor's driveway, started it up, it stalled (it was cold we assumed) restarted mid-street and drove under it's own power into his driveway, whereupon it quit and failed to restart.

Diagnosis to this point finds:

- the Fuel pump relay is viable and both getting 12v+ as well as reacting to the switched trigger signal from the Ign Key Switch.

- System has a 'siphon' pump in each tank and a main Pump to charge the Fuel Rail w/ a 30 to 45PSI pre4ssure; true & current pressure as yet unknown but the Voltage at the pump reads a nominal 7.5V on the hand-held analog meter. Llong-ass'd wire shunt, directly from the battery got the Main Pump to start spinning, but... Truck still wont start.

- Spark plugs are getting a robust spark, even if it's a healthy orange and not an optimal Blue Azure, Chekhov like plasma...

We added about an additional 5G of fresh gas to the existing fresh gas in the front tank, poured some down the throat of the Intake Manifold and were able to get the motor to catch and run... Until the gas we pored in there ran out.

In a nutshell; Truck got worse, driving from one side of the street to the other.

Sunday is back in the fray...
User avatar
TazManiac
Posts: 3701
Joined: Fri Nov 29, 2013 6:53 pm

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by TazManiac »

Lariat, Laredo, what ever: It's an 89' F150 w/ a Straight Six...
User avatar
Just Old Al
Posts: 1683
Joined: Tue Jul 31, 2012 4:43 am
Location: Wilderness of Massachusetts
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by Just Old Al »

In order (and pre-coffee):

\Find the reason for the 7.5V at the pump. Could well be the thing's being told to shut down as the engine isn't running. EFI systems do that - not specifically familiar with Fords to know.
Fuel filters in the lines? Check them first.
Check the fuel system starting at the tanks. Sounds to me like the main pump is not being fed by the siphon system. I've seen this on Jaguars - the dual-tank system refuses to feed and the engine starves. If you can plumb one side straight to the high-pressure pump (why it needs two I have no idea) then see if that will get it moving - then you can go back and diagnose the actual problem.
"The Empire was founded on cups of tea, mate, and if you think I am going to war without one you are sadly mistaken."
User avatar
jwhouk
Posts: 6053
Joined: Wed Aug 01, 2012 7:58 am
Location: The Valley of the Sun, Arizona
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by jwhouk »

Possible solution.

EDIT: I'd just call it an F-150, myself.

DOUBLE EDIT: Just so no one thinks I'm talking out my posterior, I did work at a Ford dealership in the early 90's, when this thing was late-model.
Last edited by jwhouk on Sun May 27, 2018 6:27 pm, edited 1 time in total.
"Character is what you are in the dark." - D.L. Moody
"You should never run from the voices in your head. That's how you give them power." - Jin
User avatar
Atomic
Posts: 2948
Joined: Tue Jul 31, 2012 12:39 am
Location: Central PA
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by Atomic »

89 eh? OK - low fuel pump voltage, fuel pressure not certain. Runs OK on gas poured down the throat. Hmmm...

If this has manifold electronic fuel injectors, low fuel pressure will run way lean, and might not be enough to catch. Can you smell tailpipe gas after cranking? No smell = no injection. Ditto for carb injection, but there's an option there. Crank it, let it pressure up, then stop. Look down the carb and rotate to full throttle. Can you see/hear the acceleration jet squirt? Some EFI systems still have a squirt gun for when you drop the pedal. No squirt = no gas to the carb.

One easy trick is to pull all the fuses and re-insert to knock off any corrosion. Same with relays. Have you checked the vacuum system? Was it rough running or smooth when you did gas down the throat trick?
Don't let other peoples limitations become your constraints!

My Deviant Art scribbles
The Atomic Guide to Basic GIMP Stuff
User avatar
TazManiac
Posts: 3701
Joined: Fri Nov 29, 2013 6:53 pm

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by TazManiac »

Yeah, Thx fellas. I think I'm either hoping to find a Ford Guru here undercover or (more likely) just venting, all off topic'ly and stuff...

I have been all over CarGurus' web site (it's got itself pretty highly weighted on Google Searches...) and there are a few Ford related online forums, one of which I posted pretty much the same post to.

I'm back at it again this morning, but it's a bit hard to try and do Online Searches on the tiny cellphone screen.

I need at least a Haynes repair manual... mumble, grumble, stumble...

(huh), here it is something like 10 or 12 hours later & I thought I had sent this...

Well, to follow up with the somewhat short run at this problem I had today; I found a good portion of the 12V power supply shows up as 7.5V approx.

There is a Test port where you can jumper stuff and get error codes to blink a light (ODB1) and w/ the Ign OFF there are two wires there- one shows constant voltage the other is dead.

When you turn the Ign Switch to RUN, the place that was showing constant voltage will jump from 7.5V to 12V+,
the other one that had been dormant jumped from 0V to .... 7.5V. :shock:

Something just ain't right here. It'll be a week before I can have a go at it again.
User avatar
TazManiac
Posts: 3701
Joined: Fri Nov 29, 2013 6:53 pm

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by TazManiac »

Atomic wrote:89 eh? OK - low fuel pump voltage, fuel pressure not certain. Runs OK on gas poured down the throat. Hmmm...

If this has manifold electronic fuel injectors, low fuel pressure will run way lean, and might not be enough to catch. Can you smell tailpipe gas after cranking? No smell = no injection. Ditto for carb injection, but there's an option there. Crank it, let it pressure up, then stop. Look down the carb and rotate to full throttle. Can you see/hear the acceleration jet squirt? Some EFI systems still have a squirt gun for when you drop the pedal. No squirt = no gas to the carb.

One easy trick is to pull all the fuses and re-insert to knock off any corrosion. Same with relays. Have you checked the vacuum system? Was it rough running or smooth when you did gas down the throat trick?

OK, I had a 'not-yet-sent' post, and in between Atomic posted the above so I'm going to try and reply, point by point:

- The Truck is an '89 F150 w/ a Dual Gas Tank system (more on this later), and a Fuel Rail type Electronic Fuel Injection. That means each of the Cylinders has a independent Injector and each Injector gets a triggering electrical pulse that tells it when to 'squirt'. (As opposed to Throttle Body injectors that pretty much replace a carb's jets with a single/dual injector that runs all the time), or like the VW old school Mechanical Injection System (Bosch CIS).

- I haven't been back at the tail pipe to determine if there is a Lean or Rich condition. I'm assuming it's running too lean to catch, for reasons related less to obstruction in the lines and more so to a Low Voltage condition.

- re: 'Easy Trick'- In another place on the Interwebz I am known for championing the free flow of electrons, esp as relates to automotive 12V systems. Reconditioning & Augmenting the Chassis Grounds is a good size chapter in the hymnal as sung by the Church of the Free Electron, and I've been suggesting the truck owner break out the Contact Cleaner and (at least petroleum jelly, if not) Dialectic Grease and in doing so open every single wire junction in the Engine Bay Loom as well as the Fuse Box, and so on, de-oxifying and lubing up as he goes.

I'm joining a few F150/Ford (shudder) Forums to cast my lot amongst the experienced, but it's hard to winnowing the wheat berries from the chaff.
User avatar
TazManiac
Posts: 3701
Joined: Fri Nov 29, 2013 6:53 pm

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by TazManiac »

PS- there is a well known problem where the dual tank system has a check valve type failure and instead of the siphon pump (one in each tank) doing it's/thier job to feed the Main, High Pressure, Pump, one will back fill the other tank, often to overflowing.

Having unmetered, flammable fluid pour out on the ground merited a period of recall, but that may well have expired by now- I'm investigating...
User avatar
DinkyInky
Posts: 2382
Joined: Tue Jul 31, 2012 9:38 am
Location: Where there's more than Corn.
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by DinkyInky »

Those 80's Ford trucks dual tank systems had so many recalls...I absolutely hated getting one in the shop. I'd take one look at it, walk out and into the office, slam door, scream a string of obscenities that would blush a USMC Drill Instructor, walk out, then send them on straight to Ford.

Odds are it's that relay is buggered(apologies, I'm depressed, very tired, and stressed, so I'm probably not using the right terminology). The f'ed up voltage was present in every one we had at Luke's, and we sent them straight to Ford. Check out if the recall was ever submitted on that truck. At the worst, Ford can get you to the proper fix/parts for it if not offer a reduced fee to fix it because the truck is twenty-nine years old.
Yanno how some people have Angels/Devils for a conscience? I have a Dark Elf ShadowKnight and a Half Elf Ranger for mine. The really bad part is when they agree on something.

Aphyon chu kissa whol l'jaed.
--Safyr Drathmir
User avatar
Atomic
Posts: 2948
Joined: Tue Jul 31, 2012 12:39 am
Location: Central PA
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by Atomic »

I'll presume it has an alternator, sooo...

Allowing that the battery is putting out close to 12v, do you know if that changes when running? Basically, checking if the alternator is working properly. Then, how far down the chain from bat/alt to pump does the 12v go before it drops to 7.5v? Somewhere there's got to be a relay or connector block that is obstructing things. Then of course, there's the pump ground. Corrosion anywhere? And how many leads on the ignition switch - some connect to a master relay, some have several wire pairs, each with a contact system that can get screwed up with age.

Happy hunting!
Don't let other peoples limitations become your constraints!

My Deviant Art scribbles
The Atomic Guide to Basic GIMP Stuff
User avatar
TazManiac
Posts: 3701
Joined: Fri Nov 29, 2013 6:53 pm

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by TazManiac »

Further reason to express some sort of lovely feelings for the Dinky that is Inky- you're just reinforcing the 'tip o the hat' I've have aimed in your general direction.

As to the most recent Atomic post; It ain't currently running, so a lot of your good sense is awaiting that state of affairs.

in fact the whole 'it stopped running just getting across the street' thing is pilling on, frustration wise, by the fact that I was yelling to the owner behind the wheel to

"Keep it running so i can check some voltages..."
, and it died.

< insert emoji of a human curled up on the ground like a dead cockroach > <--- I'm trying not to internalize that, there.
User avatar
Just Old Al
Posts: 1683
Joined: Tue Jul 31, 2012 4:43 am
Location: Wilderness of Massachusetts
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by Just Old Al »

And people laugh at Lucas....humph!

All of the above is entirely valid and very good information. Even in a static key-on condition I'd be looking at voltage drops - "OK before this point it's 12 volts, after it's 9..." type measurements.

What I'd be doing here were it me is to simply backtrack the power from the fuel pump relay If you're seeing messed up voltages at multiple points then it's likely going to trace back to a large connection that's gone loose or corroded somewhere near the battery in an electrical sense.

Just ran across a similar problem on a Range Rover Classic recently - poor charging and dim everything - even throwing EFI faults. Turned out to be a bad primary connection at the starter, where the main battery cable met the feed from the alternator. Fixed that and got my 14V back.
"The Empire was founded on cups of tea, mate, and if you think I am going to war without one you are sadly mistaken."
User avatar
jwhouk
Posts: 6053
Joined: Wed Aug 01, 2012 7:58 am
Location: The Valley of the Sun, Arizona
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by jwhouk »

Dinky, now I'm hat my feeble memory has processed it, Ford dealers hated trying to fix those dual tank trucks, too.
"Character is what you are in the dark." - D.L. Moody
"You should never run from the voices in your head. That's how you give them power." - Jin
User avatar
Atomic
Posts: 2948
Joined: Tue Jul 31, 2012 12:39 am
Location: Central PA
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by Atomic »

Good stuff Al! And I just remembered a Dad trick from back in the days when voltage regulators were a brick sized box of stuff. Measure at the battery, then turn on the headlights and measure again. If you have a huge voltage drop, there's a clue.
Don't let other peoples limitations become your constraints!

My Deviant Art scribbles
The Atomic Guide to Basic GIMP Stuff
User avatar
TazManiac
Posts: 3701
Joined: Fri Nov 29, 2013 6:53 pm

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by TazManiac »

Good Stuff. I'm finding out that the Ford Volt Reg. is External and bolted to the Pass. Side.
(As opposed to the Bosch stuff I'm familiar w/ which bolts the voltage regulator to the back of the Alt...).

It'll be at least a half-week before I get hands on it again, I'll keep you all posted...
User avatar
DinkyInky
Posts: 2382
Joined: Tue Jul 31, 2012 9:38 am
Location: Where there's more than Corn.
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by DinkyInky »

jwhouk wrote:Dinky, now I'm hat my feeble memory has processed it, Ford dealers hated trying to fix those dual tank trucks, too.
Right, but Ford had a warranty on recall work to protect their mechanics, and it didn't extend to unaffiliated mechanics like Luke's where I unofficially apprenticed...not that the average troglodyte who knuckle-dragged their compensatory parcels in acknowledged me as anything more than a pair o'teeny jugs.

(Not one word you guys! Back then that was a true statement!)
Yanno how some people have Angels/Devils for a conscience? I have a Dark Elf ShadowKnight and a Half Elf Ranger for mine. The really bad part is when they agree on something.

Aphyon chu kissa whol l'jaed.
--Safyr Drathmir
User avatar
TazManiac
Posts: 3701
Joined: Fri Nov 29, 2013 6:53 pm

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by TazManiac »

'word'
User avatar
Atomic
Posts: 2948
Joined: Tue Jul 31, 2012 12:39 am
Location: Central PA
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by Atomic »

TazManiac wrote:'word'
Wave your hands in the air like you don't care
Word up!
(Dial "L" for love...)
Don't let other peoples limitations become your constraints!

My Deviant Art scribbles
The Atomic Guide to Basic GIMP Stuff
User avatar
Dave
Posts: 7584
Joined: Tue Jul 31, 2012 5:58 pm
Location: Mountain View, CA, USA

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by Dave »

DinkyInky wrote:(Not one word you guys! Back then that was a true statement!)
"This is not one word" is also a true statement. ;)

Image

(Sorry to hear that you're stressed and depressed, DinkyInky. Would send a prescription for sympathetic hugs if I could figure out how to get a pharmacy to fill it properly :( )
User avatar
Atomic
Posts: 2948
Joined: Tue Jul 31, 2012 12:39 am
Location: Central PA
Contact:

Re: 1989 Ford Lariat 4x4 pickup wont sip gas...

Post by Atomic »

It's not a Gnarfblaatt either, if anyone was confused.
Don't let other peoples limitations become your constraints!

My Deviant Art scribbles
The Atomic Guide to Basic GIMP Stuff
Post Reply