1990 FORD F-150 MISS ON CYL. 2 AND 5

  • Tiny
  • billyboy1983
  • 1990 Ford F-150
  • 250,000 miles

4.9 ltr. Straight 6 missing on 2 and 5 cyl. Good compression, fire, gas, timing and new computer. Pulled a code 81, air management 2 circuit failure. Any ideas because i've run out. Billy

Do you
have the same problem?
Yes
No
Friday, August 23rd, 2013 AT 2:54 PM

5 Replies

  • Tiny
  • mhpautos
  • Expert
  • 30,561 posts

Faulty distributor cap, vacuum leads check these first.

Was this
answer
helpful?
Yes
No
Friday, August 23rd, 2013 AT 6:09 PM
  • Tiny
  • billyboy1983
  • Member

Replaced distributer cap, rotor button and all vacuum leads seem to be ok. Still have a dead miss.
HELP.

Was this
answer
helpful?
Yes
No
Monday, August 26th, 2013 AT 10:34 AM
  • Tiny
  • mhpautos
  • Expert
  • 30,561 posts

Do you know what the spark voltage is, do you have a good hot blue spark?

Was this
answer
helpful?
Yes
No
Tuesday, August 27th, 2013 AT 3:18 AM
  • Tiny
  • billyboy1983
  • Member

I have a blue spark on all cylinder's.

Was this
answer
helpful?
Yes
No
Tuesday, August 27th, 2013 AT 11:36 AM
  • Tiny
  • mhpautos
  • Expert
  • 30,561 posts

I feel that there must be a vacuum leak affecting these cylinders, ensure that this is not the case first.

Was this
answer
helpful?
Yes
No
Thursday, August 29th, 2013 AT 2:45 AM

Please login or register to post a reply.

Similar Questions