99 grand Cherokee 4.0 engine swap timing trouble????

Asked by Aug 20, 2016 at 09:53 AM about the 1999 Jeep Grand Cherokee Laredo 4WD

Question type: Maintenance & Repair

Motor blew in my 99 grand Cherokee 4.0 I bought a
2000 GC with a recently rebuilt motor but the
transmission was bad but the motor ran really good
less than 30,000 on it anyway I swapped motors
and got everything hooked up but when I went to
start it it's acting like its firing at the wrong time
back firing out the intake and so forth I've checked
pretty much everything in getting spark at the plugs
the only thing is that after I tried to start it I noticed
that I forgot the crankshaft position sensor bolt so I
put it in then I realized it didn't have the spacer on it
could this cause this problem also the vehicle set
since January so I'm sure the gas is bad could bad
gas cause it not to start and backfire out the
intake?? It's my daughters jeep and she starts her
freshman year of college this week so she really
needs this car so any input would be a godsend so
please help!   Thanks everyone for your time on this
never ending post.

1 Answer


The spacer is there to make sure the air gap is correct from the sensor and trigger pawl, check the end of the sensor and make sure it was not damaged during cranking, also bad fuel will cause pop back, shelf life of today's fuel just sitting in a fuel tank is at best 60 days without any additives.

Your Answer

Jeep Grand Cherokee Experts

  • #1
  • #2
    Tom Demyan
  • #3
View All

Related Models For Sale

Used Jeep Cherokee
396 Great Deals out of 59,534 listings starting at $3,995
Used Dodge Durango
300 Great Deals out of 23,824 listings starting at $1,500
Used Ford Explorer
1,047 Great Deals out of 70,328 listings starting at $2,100
Used Toyota 4Runner
326 Great Deals out of 25,158 listings starting at $1,750
Used Jeep Wrangler
426 Great Deals out of 18,823 listings starting at $2,990
Used Chevrolet Tahoe
794 Great Deals out of 41,861 listings starting at $1,980
Used Ford F-150
2,797 Great Deals out of 212,249 listings starting at $1,300
Used Chevrolet Silverado 1500
2,351 Great Deals out of 173,077 listings starting at $699
Used BMW X5
340 Great Deals out of 15,077 listings starting at $2,995
Used GMC Yukon
590 Great Deals out of 22,144 listings starting at $2,145

Used Cars For Sale

2018 Jeep Grand Cherokee Laredo 4WD For Sale
6,350 listings starting at $26,851
2017 Jeep Grand Cherokee Laredo 4WD For Sale
14 Great Deals out of 1,118 listings starting at $23,000
2016 Jeep Grand Cherokee Laredo 4WD For Sale
19 Great Deals out of 568 listings starting at $20,500
2015 Jeep Grand Cherokee Laredo 4WD For Sale
21 Great Deals out of 1,056 listings starting at $17,995
2014 Jeep Grand Cherokee Laredo 4WD For Sale
10 Great Deals out of 790 listings starting at $13,597

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.