1996 C1500 silverado 5.7l vortec engine. Running rich

10

Asked by simperfi84 Jan 16, 2020 at 10:58 AM about the Chevrolet Silverado 1500

Question type: Maintenance & Repair

I have a 96 chevy c1500. I have a new factory GM engine it seems to be
running rich. Exhaust has a strong fuel smell. All O2 sensors are new,
new cats, new MPFI system, with the exception of the EGR and MAF
sensors, all others are new (aftermarket). Here are my live data from
testerday at 66mph according to scan tool, RPMs 2052.  
STFT BK1 -0.8 to 0.8
LTFT BK 1 13.3
STFT BK 2  -0.8 TO -1.6
LTFT BK 2 14.8
MAP 15 INHG
SPK ADV 38
IAT 79 DGREES F
MAF 5.28 LB/ MIN
TPS 10.3
ECT 194
IDLE TRIMS ARE AS FOLLOWS
STFT BK 1 -1.6 TO 0.8
LTFT BK1 4.7
STFT BK 2  -1.6 TO 08
LTFT BK 1 1.6

I do have a difference of about 5 MPH BETWEEN speedometer and
what scan tool shows. Speedo showed 71mph . I believe the ECT TEMP
should show between 200 to 205 degrees for normal operating temps
for the 5.7l .. Been told these engines like AC delco parts. I may go
ahead and replace ECT with OEM. Thoughts please. No codes by the
way.

2 Answers

90

Thats not rich thats lean.. and since its lean under load check the maf sensor if its dirty or suspect a weak pump

10

Thanks Guru84BD1, I can never keep that straight in my head, thanks for setting me straight on that. Fuel pump is new and got 62+ pressure. MAF is original , So I will clean it and see how it does and go from there. Thanks again I have a direction now.

Your Answer:

Chevrolet Silverado 1500 Experts

  • #1
    Rowefast
    Reputation
    8,260
  • #2
    John Carson
    Reputation
    7,700
  • #3
    Andrew Olsen
    Reputation
    7,330
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used GMC Sierra 1500
78 Great Deals out of 4,444 listings starting at $520
Used Ford F-150
113 Great Deals out of 7,858 listings starting at $871
Used Chevrolet Silverado 2500HD
10 Great Deals out of 658 listings starting at $699
Used RAM 1500
197 Great Deals out of 12,797 listings starting at $5,500
Used Dodge RAM 1500
5 Great Deals out of 168 listings starting at $3,400
Used Toyota Tundra
13 Great Deals out of 598 listings starting at $5,995
Used Toyota Tacoma
22 Great Deals out of 758 listings starting at $1,013
Used Chevrolet Tahoe
6 Great Deals out of 515 listings starting at $2,950
Used Chevrolet Colorado
15 Great Deals out of 933 listings starting at $2,768
Used Ford F-250 Super Duty
8 Great Deals out of 693 listings starting at $7,900
Used GMC Sierra 2500HD
7 Great Deals out of 552 listings starting at $9,850
Used Chevrolet Camaro
20 Great Deals out of 577 listings starting at $8,998
Used Dodge Charger
24 Great Deals out of 562 listings starting at $2,900
Used Dodge RAM 2500
3 Great Deals out of 41 listings starting at $4,999
Used Nissan Titan
7 Great Deals out of 353 listings starting at $8,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.