1978 Ford F-150 Timing seems to change

Tiny
SRBZ
  • MEMBER
  • 1978 FORD F-150
  • 5.8L
  • V8
  • 2WD
  • AUTOMATIC
  • 65,723 MILES
I brought the truck in for CA smog check today and it passed emissions really well, but failed for timing.
It was 7º btdc instead of 14º btdc.

I never really paid much attention to the timing before because it is electronic ignition and the distributor has been frozen in place for 20 years or so.

I looked at my smog check paperwork from 2 years ago, and see that I have only driven the truck about 400 miles. The timing in 2012 was 14º.

What could cause the timing to change in such a few number of miles?

I put less than 1,000 miles a year on it because I only use if for picking things up.

I went back through my previous smog checks and see that the timing has varied, though since it never failed smog for timing I didn't pay attention to it.

Year Mileage Timing RPM
2014 65723 7º doesn't say but I saw him measure it at idle
2012 65382 14º
2012 65376 14º it failed this test because EGR passed was plugged with carbon
2008 63357 14º
2006 62367 16
2004 60664 12º It was sitting on the rollers and didn't even move from the pretest yet changed
2004 60664 8º I did a pre test that year, but it passed timing even though off 6º

The truck is a Federal vehicle, not California.
I got it in 1985 with about 38,000 miles. It has always run well and no symptom of timing chain jumping.

Since I suspect it will be difficult to get the distributor unstuck, is there some component that might have worn to cause the timing variation?

If not, any suggestion for unsticking the distributor, or methods not to try because they will break something?

I have a timing light to check it.

Thanks


Do you
have the same problem?
Yes
No
Friday, January 31st, 2014 AT 4:32 PM

9 Replies

Tiny
SATURNTECH9
  • EXPERT
Only thing I can think of is maybe a worn distributor the timing if it were a little loose maybe. If that has a nylon or aluminum cam sprocket that could be a little worn. Its not off by much I would just set the timing. Get a product called deep creep its penetrant made by a company called sea foam. It works amazing freeing up stuck things. Let soak in for a while.
Was this
answer
helpful?
Yes
No
+1
Friday, January 31st, 2014 AT 5:04 PM
Tiny
CJ MEDEVAC
  • EXPERT
SOME PEOPLE ARE NOT UP TO PAR ON HOW TO USE A TIMING LIGHT

BEING IN A NON-EMISSION TESTED REGION I DON'T KNOW HOW THEY PERFORM THESE TESTS

I DO KNOW HOW TO TIME AND ALSO CHECK THE MECHANICAL ADVANCE AND THE VACUUM ADVANCE (TO INSURE THEY PERFORM AS THEY SHOULD)

NOT KNOWING THE EXPERTISE OF YOUR "TEST FELLER". HAS HE/ THEY BEEN TESTING TIMING "AS IS" AND IN A HURRY?

. OR ARE THEY DISCONNECTING THE THE VACUUM ADVANCE AS A "REAL TEST" SHOULD BE DONE?

. WHAT KINDA MACHINE ARE THEY USING?

.A TIMING LIGHT?

. AN ADJUSTABLE TIMING LIGHT. SO MANY PEOPLE ARE LOST IN USING AN ADJUSTABLE ONE. THE PUPPY SHOULD BE SET ON "ZERO" TO TEST. THE ADJUSTABLE ADVANCE TIMING LIGHT IS REALLY THERE FOR "RACING/ PERFORMANCE ORIENTED PEOPLE"

I'VE SEEN LOTS OF FOLKS SET THE GUN TO THEIR "DESIRED TIMING" THEN ATTEMPT TO SCOOT THE DISTRIBUTOR AND MARKS TO MATCH. IT JUST DON'T WORK THAT WAY!

A PLAIN JANE TIMING LIGHT WORKS BEST FOR ME

. BEING THAT WE ARE BEING SERVICED BY MANY OF THE "NINTENDO GENERATION". OUR VEHICLES FALL INTO THE "DINOSAUR AGE" TO THE "NG", THEY ARE OBSOLETE. MAYBE THEY ARE NOT TESTING CORRECTLY. IGNORANT AS TO HOW?

BEINGS THAT YOUR RIG SEEMS TO RUN WELL.I CANNOT SEE THAT IT HAS JUMPED TIMING.I CAN SEE THE "WEAR FACTOR" PLAYING A PART. BUT EVEN WEAR, IS USUALLY MINIMAL, NOT 7 DEGREES!

SAY YOU HAVE A LIGHT?

HOW 'BOUT A DWELL/ TACH. PAWN SHOPS ARE A GOOD CHEAP SOURCE!

IDLE SPEED PLAYS A BIG PART IN SETTING THE CORRECT TIMING---ALSO HELPFUL TO TWEAK THE OLE CARB. TOO MUCH IDLE SPEED AND THE MECHANICAL (CENTRIFUGAL) ADVANCE STARTS MOVING THE TIMING

BASICALLY, IF EVERYTHING IS "GOOD"---YOU SET THE BASE TIMING AND THE TWO ADVANCES SORTA FOLLOW ALONG

. WANT SOME HELP CHECKING YOUR "ACTUAL TIMING". THEN SEEING IF THE TWO ADVANCES WORK RIGHT. ALONG WITH IDLE SPEED.I HAVE LOTS OF PICS OF MY JEEP 6 CYLINDER REPAIRS, I FEEL SURE YOU COULD "TRANSLATE" TO THE SAME PROCEDURES TO YOUR V-8

A LOT OF FACTORS HERE---IDLE SPEED---IS THE "IDLE STEPS" (ON THE CHOKE) WORKING RIGHT?---VACUUM LINES IN GOOD SHAPE?

I WOULDN'T TRADE MY TWO EZ TO MAINTAIN DAILY DRIVER DINOSAURS FOR THE WORLD!

YOUR TURN

THE MEDIC
Was this
answer
helpful?
Yes
No
Friday, January 31st, 2014 AT 7:04 PM
Tiny
SRBZ
  • MEMBER
It didn't look like he had the vacuum advance disconnected, but I didn't see any point in mentioning that, because then it would have been even less.

It did look like he had an adjustable timing light.
It had a digital readout on the back and it looked like it was counting down from 16 to 0.

He was middle aged, has worked there several years, and seems to know what he is doing.
Was this
answer
helpful?
Yes
No
Friday, January 31st, 2014 AT 7:41 PM
Tiny
CJ MEDEVAC
  • EXPERT
ROGER

CORRECT/ MAYBE---IF THE VAC ADV IS HOOKED TO "PORTED VACUUM". IT PROBABLY WOULD NOT CHANGE AT ALL IF IT WERE REMOVED FROM THE DISTRIBUTOR (THE LINE WOULD BE DEAD, UNTIL THE THROTTLE PLATE WAS CRACKED OPEN MORE) (AGAIN, ANOTHER FACTOR, IS THE CARB ADJUSTED RIGHT?)

IF IT'S HOOKED TO MANIFOLD VACUUM--THE DIST WOULD BE ADVANCED ALL OF THE TIME.'TILL IT'S UNDER LOAD

THE OTHER FACTORS WITH THE TWO ADVANCESSPRING BREAKS, MECHANICAL ADVANCE ADVANCES ALL OF THE TIMEIF YOU DON'T SEE THIS WITH YOUR EYES (HARD TO GET TO) ----OR---FAIL TO CATCH IT WITH THE "SIMPLE TIMING LIGHT TEST". SUDDENLY YOU NOTICE THAT YOUR PERFORMANCE LACKS A LOT

YOU ARE FOOLED INTO THINKING YOUR TIMING IS WAY OFF----SO YOU CHANGE IT----IT'S RIGHT (YOU THINK) REALLY, IT'S NOW RIGHT AGAIN AT IDLE. BUT THERE IS ABSOLUTELY NO ADVANCE AS THE ENGINE SPEED INCREASES. NOW YOU ARE REALLY CONFUSED!

. VERIFYING IT WORKS WITH THE LIGHT, WILL KEEP YOU FROM TEARING INTO THE DISTRIBUTOR NECESSARILY. OR WILL LET YOU KNOW THERE IS A PROBLEM

. SAME GOES FOR THE VAC ADV. THE DIAPHRAGM COULD BE SHOTTHE LINKAGES WITHIN THE DIST MAY BE SCRAPING/ DRAGGING/ COME LOOSE. RESULTING IN SLOW MOVEMENT/ NO MOVEMENT ALL/ A VACUUM LEAK.I HAD EVERY ONE OF THESE ISSUES WITH MY JEEPS "PRESTOLITE" DIST AND IGN SYSTEM SEVERAL (TOO MANY) TIMES. SO.I UPGRADED MY '77 CJ 5 TO THE "FORD MOTORCRAFT SYSTEM" (WHICH WAS STANDARD FROM 1979 ON UP)

WANNA TRY IT TO DO THIS YOURSELF. SET IT. CHECK THE TWO ADVANCES?

GOT THE DWELL/ TACH TO CHECK IDLE SPEED. WE CAN'T "HALFWAY" DO THIS!

NOT SURE WHAT YOU HAVE GOING ON---IF YOU WANNA GET MR. DIST MOVING. MARK THE DIST AND THE BLOCK WITH A DEEP SCRATCH WHERE THE MEET.1/2 WRENCH OUGHTA LOOSEN IT. PENETRATING OIL/ ETC MAY FREE IT. JUST DON'T PICK IT UP OUTTA OF THE BLOCK !

YOUR TURN. SORRY, I TYPE SLOW!

THE MEDIC
Was this
answer
helpful?
Yes
No
Friday, January 31st, 2014 AT 8:28 PM
Tiny
SATURNTECH9
  • EXPERT
The main thing with the mechanical advance is Make sure the Weights move freely and aren't stuck rusted in place. Also the springs are good you should only be getting mechanical advance off idle not at idle. Also make sure your vacuum advance diaphragm holds vacuum. You would use a hand vacuum pump to pull a vacuum on it and watch the gauge on the pump to make sure it holds vacuum.
Was this
answer
helpful?
Yes
No
Saturday, February 1st, 2014 AT 7:37 AM
Tiny
SRBZ
  • MEMBER
I went to a STAR smog check station.

Is the timing measured by the wires they hook up under the hood connected to their computer machine and he was just verifying with the hand held timing light, or is the timing checked manually with the light only?

If the timing is checked automatically, I don't think operator error, as suggested in one of the responses is likely.

The timing was off 7 at idle, vacuum advance should have been disconnected anyway, and mechanical advance you said doesn't kick in until over idle.

The timing had been measured at the correct 14 just 400 miles earlier.

I don't notice any difference in how it runs either.
I would think a 7 retard would make it idle slower at least and maybe affect low end performance.
Was this
answer
helpful?
Yes
No
Saturday, February 1st, 2014 AT 7:54 AM
Tiny
SATURNTECH9
  • EXPERT
7 degrees isnt that much to really effect performance as far as his timing light the readings dont go into the machine automatically he has to enter the readings he found.
Was this
answer
helpful?
Yes
No
Saturday, February 1st, 2014 AT 12:41 PM
Tiny
CJ MEDEVAC
  • EXPERT
ME, JUST BEING AN OLE RURAL ROUTE KINDA FELLER

MY UNDERSTANDING OF THIS IS WE CAN'T LEGALLY DRIVE THE TRUCK TILL YOU MAKE SOMEONE HAPPY

NOT BRAGGING OR NUTHIN', BUT YOU COULD MESS UP MY JEEP'S IDLE--MESS UP MY MIXTURE SCREWS---SNATCH THE DISTRIBUTOR OUT (AND MOVE MY ENGINE)

...........I COULD HAVE HIM UP AND RUNNING TO MY PREVIOUS SPECS, IN 30 MINUTES OR LESS, TO INCLUDE TESTING BOTH ADVANCES!........OR THE PIZZA IS FREE!

MAYBE YOU AREN'T THAT FAST.......BUT YOUR LABOR IS FREE LIKE MINE

SO...............IF YOU SPEND $10 AT THE PAWN SHOP (YOU WILL AT LEAST HAVE SOMETHING USEFUL) , THEN TIME IT, AS THEY DESIRE WITH YOUR TIMING LIGHT AND DWELL/ TACH.....CHECK YOUR ADVANCES ..............IF THERE IS A DISTRIBUTOR PROBLEM, FIX IT [WE CAN HELP DO THIS TOO!] .............LOOKS LIKE A REBUILT ONE WITH A LIFETIME WARRANTY CAN BE HAD FOR UNDER $45

HERE'S WHAT YOU ARE UP AGAINST

A) IDLE/ TIMING EZ FIX
B) ADVANCE ISSUESEITHER VACUUM LINE PROBLEMS OR REPLACE THE DISTRIBUTOR
C) THE OLE HARMONIC BALANCER HAS SLIPPED (NOW THE TIMING MARKS AIN'T TRUE---NEED A NEW ONE (THIS TOO, WILL FOOL YOU WHEN YOU TIME IT, YOU'LL BE CHASING YOUR TAIL, TILL YOU FIGGER IT OUT! ....SEE ME IN THIS LINK

http://www.2carpros.com/questions/1971-ford-f-100-wont-start-29328527
.
.
.

RECAP.......TIME IT THE RIGHT WAY....DO YOUR CHECKS.........HOW CAN IT FAIL?????........THIS AIN'T HARD!
.
.
I INHERITED PAP'S 1976 F-150 351 WINDSOR 4 YEARS AGO---I HAVEN'T BROUGHT IT HOME YET, I DRIVE IT AROUND THE YARD ONCE A MONTH.....THIS IS THE ONLY PIC I COULD FIND IN A HURRY

THE MEDIC

Was this
answer
helpful?
Yes
No
Saturday, February 1st, 2014 AT 5:22 PM
Tiny
CJ MEDEVAC
  • EXPERT
LOST PIC? TRY AGAIN

THE MEDIC
Was this
answer
helpful?
Yes
No
Saturday, February 1st, 2014 AT 5:24 PM

Please login or register to post a reply.

Recommended Guides