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\'93 Jeep Grand Cherokee 4.0 Crank No Start (Replaced a LOT)

Home Forums Stay Dirty Lounge Service and Repair Questions Answered Here \'93 Jeep Grand Cherokee 4.0 Crank No Start (Replaced a LOT)

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This topic contains 5 replies, has 2 voices, and was last updated by Matt Mosqueda Matt Mosqueda 4 months, 3 weeks ago.

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  • #989172
    Matt Mosqueda
    Matt Mosqueda
    Participant

    Buckle in for this one guys…

    I’ve been working on this for a LONG time and it started initially as being difficult to start in the cold and starting right up no problem when warm. I had before this replaced all the sensors at the throttle body, some of them even twice (IAC and TPS). I have also replaced all the plugs, plug wires, distributor cap and rotor all less than a year ago with no problem. Once it became increasingly difficult to start I began to look at fuel. I have a new pump that I haven’t put in yet because I can confirm that the other one still “pumps” fine (although I know this doesn’t necessarily mean it hasn’t failed in another way). It eventually sat for a few months because of the colder winter temps and would no longer start at all. Other things I have also recently done is replace the entire fuel rail itself, all fuel injectors with the 4-hole injectors, the fuel pressure regulator (on the rail), and even replaced (most) of the vacuum lines. As you can tell by this point we have been doing a lot of guess and checking but to be honest I’ve rebuilt nearly this entire car from the ground up from suspension to steering to the performance upgrades and cosmetics, ect. I considered the rotor being put improperly back on the distributor and was able to use a pressure gauge to find TDC on cylinder 1 and re-calibrate the timing properly. I have just purchased the ignition coil as well and will be installing that tomorrow but honestly I’m not that hopeful. I realize it could also be the camshaft position sensor, that is the very last thing I can think of. This entire time it has also been hooked up to a 40amp power supply that I can turn up to 200amp if I need to try giving it an extra little kick. I’ve tried starting fluid.. I feel like I’ve tried it all. Any ideas?? Am I missing something obvious??

Viewing 5 replies - 1 through 5 (of 5 total)
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  • #989173
    Matt Mosqueda
    Matt Mosqueda
    Participant

    I had meant crank position sensor FYI not cam position sensor… Also should add that I used a jumper on the fuel relay (which was also replaced) in order to drain my tank and put in fresh fuel to rule out bad gas since it has been sitting awhile.

    #989181
    Nightflyr *
    Richard Kirshy
    Participant

    It appears you’ve spent quite a bit on firing the parts cannon.
    You really need to first find out what your missing IE. spark, fuel, air, compression when you have the no start condition.

    Going by your statement: I’ve tried starting fluid..
    Put the fuel portion of the equation to the side for now and focus on the other 3

    #989189
    Matt Mosqueda
    Matt Mosqueda
    Participant

    I am going to compression test tomorrow, need a day off from it… I am thinking spark related. Waiting to borrow a multimeter from a friend soon to test. Mine was in the trunk of another vehicle when I was rear ended and it got destroyed. Needless to say its been a long few weeks lol

    #989433
    Matt Mosqueda
    Matt Mosqueda
    Participant

    Just to give an update, I was able to get it started yesterday FINALLY. It was quite nice out plus using the new ignition coil was able to get it started. I let it get up to operating temp and then shut it off. Also tested reliability by making sure it started repeatedly. Today, it’s cold outside and also dead again. I even replaced and put a brand new battery in it because I thought we were almost done. Not sure why it won’t start in the cold even with practically new everything. I can guarantee that when it warms up again it’ll start like its no problem at all. What could cause it to be so picky about temperature?

    #989434
    Matt Mosqueda
    Matt Mosqueda
    Participant

    Update again. I figured it out. It’s the computer itself. Apparently Jeeps are known for a few bad capacitors on the board preventing them from starting when its cold. I went out and heated up the computer with a hairdryer and it started up no problem. Looks like we are going to be pulling the board out and installing 3 new 220 uf 35wvdc capacitors.

Viewing 5 replies - 1 through 5 (of 5 total)

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