Suburban 1/2 Ton 2WD V8-454 7.4L (1987)
View D
View E
E.
Add one additional 3/16" hole to plastic bracket and two 1/8" holes in Air Cleaner proper location using revised bracket as hole template
(See View C and D).
F.
Mount bracket so Map Sensor vacuum connection faces down toward engine, using two 8-3x1/2" sheet metal screws, P/N 447164.
G.
Install vacuum hose harness, P/N 10129600 (See View D and E).
IMPORTANT:
On trucks not equipped with an accessory vacuum fitting in the manifold, install fitting, P/N 14088336 and use caps, P/N 343350 to plug any
unused port.
H.
Reinstall electrical.
4.
On 1987-89 Check Control Idle Speed
A.
On fully warm engine, Spec. is 750 RPM in Drive for Automatic Transmission and 800 RPM in Neutral for Manual Transmission.
B.
IAC counts on both transmission should be between 5-30 counts.
