Engine - Loss of Power or Cruise Set Speed, Hesitation

Bulletin No.:
T-93-49

File in Group:
6

Number:
34

Corp.Ref.No.:
216306

Date:
Jan. 1993



SUBJECT:
LOSS OF POWER, HESITATION, LOSS OF CRUISE SET SPEED ON HIGHWAY

MODELS AFFECTED:
1993 ELDORADOS AND SEVILLES


Some 1993 Eldorados and Sevilles may exhibit loss of power, hesitation, or loss of cruise set speed during highway driving. This condition may be caused by a reduction in fuel supply. This reduction in fuel supply maybe verified by monitoring fuel pressure during the condition. A drop in fuel pressure will be noted.

Examination of the modular fuel sender may reveal evidence of the convoluted fuel feed tube having been pinched or restricted. This is caused by excessive vacuum level in the fuel tank which results in fuel tank collapse.

Inspect the canister fresh air vent pipe for restriction or pinching as follows:





Northstar Equipped Vehicle - At the air/water separator mounted on the rear suspension) check the rubber elbow for either the separator nipple or nylon vent pipe being inserted too far into the elbow. Adjust nipple or pipe as necessary to eliminate the restriction. Refer to Figure 1.






4.9L Equipped Vehicle - Correct any obvious pinching or restriction in the vent pipe. Refer to Figure 2.



Replace the sender assembly with revised sender, P/N 25028545.

Parts are currently available from GMSPO.

For warranty purposes use Labor Operation T6707 at 1.4 hours.