• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

compression test on friends car, outlook not good

  • Thread starter Thread starter 91lxvert
  • Start date Start date Oct 4, 2004

91lxvert

Member
Dec 13, 2003
110
0
16
Oct 4, 2004
#1
  • Oct 4, 2004
  • #1
ok my friend has an 87 that he put a shortblock in it. the short block was a stock rebuild with a summit rebuild kit in it with the hyperutetic pistons.

he also has a trick flow stage 1 cam, a explorerintake with spacer, 70mmtb & spacer

we got it running and it idled with a little adjustment but ran really rich down low and had no get up and go so we assumed was the speed density, so we converted to mas air and the car runs much smother, but it is still a gutless wonder, all plugs are new ran em for 2 days all still look new except for #6(was slightly brown)

so we pulled compression and have 112 on all except #6 which is 124

this seems low to me

car doesent smoke out the back, but is slowly loosing coolant over the past 2 weeks or so

the reason for the engine change is the number 6 head bolt snapped in the old block, blowing the gasket, he had the extra block already done so threw this one in, with the old heads(probably warped the head when bolt went)

we pulled codes and got code 91 (ego sensing lean) fuel pressure is 37

anyone know whats going on?

thanks
 

91lxvert

Member
Dec 13, 2003
110
0
16
Oct 5, 2004
#2
  • Oct 5, 2004
  • #2
anyone got any ideas
 

giddyup306

Founding Member
Oct 22, 2002
3,041
2
59
Oct 5, 2004
#3
  • Oct 5, 2004
  • #3
I say your burning coolant. Did you by chance surface the heads?
 
You must log in or register to reply here.

Similar threads

Progress Thread Giving an abandoned 88 GT project a new chance at life
  • jaketractor
  • Jan 9, 2025
  • Fox 5.0 Mustang Tech
  • 2
Replies
27
Views
2K
Fox 5.0 Mustang Tech Jul 20, 2025
Noobz347
J
89 2.3 LX running rich, hesitation on acceleration, high and hanging idle Help!
  • jpstucky
  • Jun 13, 2023
  • 2.3L (N/A & Turbo) Tech
Replies
4
Views
3K
2.3L (N/A & Turbo) Tech Jun 15, 2023
jpstucky
J
Betty white budget build
  • Stevenmverrill
  • Jun 16, 2023
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
6
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 15, 2023
2Blue2
R
Help please. Burns oil, low compression but no broken rings.
  • rednewedge
  • Apr 25, 2020
  • SN95 4.6L Mustang Tech
Replies
1
Views
1K
SN95 4.6L Mustang Tech Apr 30, 2020
08GT500
T
Toploaders
  • TRush
  • Nov 18, 2019
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
9
Views
3K
1965 - 1973 Classic Mustangs -General/Talk- Dec 16, 2019
bartl
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?