1994 Chevrolet Blazer Backfiring 350

Tiny
BRYCESHAGEN
  • MEMBER
  • 1994 CHEVROLET BLAZER
  • V8
  • 4WD
  • AUTOMATIC
  • 200,000 MILES
What it does: Hesitates and backfires. I replaced: plugs, wires, cap, rotor, coil, ICM, oxygen sensor. Observations: I noticed some wear on the inner-part of the cap, like the rotor was rubbing and when I replaced the ICM, the problem worsened.
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Wednesday, October 29th, 2014 AT 10:34 AM

3 Replies

Tiny
CJ MEDEVAC II
  • MEMBER
  • 222 POSTS
IF YOU GRAB THE ROTOR BUTTON SHAFT, CAN YOU WOBBLE IT (AT ALL)?

IT SHOULD STANDFAST

THE DAMAGE YOU DESCRIBED IS NOT NORMAL AND MAY CAUSE YOUR BEGINNING SYMPTOMS

SOME CW AND CCW ROTATIONAL MOVEMENT IS NORMAL

WOBBLE OFF OF IT'S AXIS IS NOT!

ARE YOU CAPABLE OF CHANGING IT YOURSELF? (I MIGHT BE ABLE TO ASSIST IN OBTAINING A POSSIBLE GOOD PRICE AND MAYBE EVEN IN CHANGING IT

TIME FOR A NEW DISTRIBUTOR (REMANS WORK JUST FINE TOO!)

THE MEDIC
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Wednesday, October 29th, 2014 AT 5:39 PM
Tiny
BRYCESHAGEN
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  • 2 POSTS
Thank you for your reply! Yes, there is a little play in the shaft which would explain the cap scoring. I am able to change it myself, but wanted to reassure myself it needs changing before doing so. Thank you again for your help.
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Thursday, October 30th, 2014 AT 11:22 AM
Tiny
CJ MEDEVAC II
  • MEMBER
  • 222 POSTS
POUR OVER THE INFO IN MY LINK - IT MAY HELP YOU ALOT

IF YOUR SET UP IS SIMILAR TO MY '77 JEEP

HIDE THE KEYS

MEASURE THE BODY OF THE DISTRIBUTOR FROM A KNOWN POINT (SEE MY PIC BELOW)

REMOVE THE CAP

MARK EXACTLY WHERE THE ROTOR BUTTON IS POINTING ON THE OLD DISTRIBUTOR (SEE PIC 2 BELOW, OF MY '46 WILLYS JEEP ENGINE)

(MY PICS WERE MADE FOR OTHER FOLKS' QUESTIONS, SO SOME INFO MAY NOT PERTAIN TO YOU, I'M JUST USING WHAT I GOT)

NOW YOU CAN SNATCH IT OUT - NO NEED TO FIND TDC DOING IT THIS WAY

OK NOW TAKE THE NEW DISTRIBUTOR AND "TRANSFER" THE MARK YOU MADE OF THE ROTOR BUTTON'S POSITION ON THE OLD ONE, TO THE NEW ONE (MEASURE FROM SOMETHING ON THE DISTRIBUTOR BODY TO PLOT IT CORRECTLY

INSTALL THE NEW DISTRIBUTOR

INSURE THE BUTTON LINES UP WITH THE MARK ON THE BODY

AT THE SAME TIME THE DISTRIBUTOR BODY SHOULD BE MEASURED BACK TO THE SAME SPOT (AS IN MY PIC)

IF BOTH PLACES WERE MEASURED/ INSTALLED CORRECTLY, IT SHOULD LOOK EXACTLY AS THE OLD ONE DID, PRIOR TO IT'S REMOVAL

IF YOU MOVED THE CRANKSHAFT AT ALL DURING THIS PROCESS, YOU HAVE MESSED UP THE SYNCHRONIZATION OF THE TIMING - YOU MUST NOW GO THRU THE PROCESS OF FINDING "TDC" (IN OTHER WORDS, DO IT ALL OVER AGAIN, THE HARD WAY!")

LEMME KNOW HOW IT GOES

(I THINK I 'SPLAINED IT ALL RIGHT!)

THE MEDIC
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Thursday, October 30th, 2014 AT 4:03 PM

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