New engine won't start

[Redcow92]

I install a new engine in my TJ and now it does not start...will crank over just fine plenty no fuel pressure or fire to the plugs. relays are all good as are the fuses. I have checked the crank trigger it is good and power to coils and cam sensor... no codes just the security key with a slash through it....do I need to have my computer reprogrammed? Went to dealership thinking that is what I needed and so guru there tells me it is the ring on the flywheel that the crank trigger reads ...I say bs ....I used the same flywheel and transmission on my install...I believe the flywheel will only go on one way because the bolt holes wont line up if they are not correct. when I turn the key on i hear nothing from the fuel pump and get no fuel pressure when I give it power it runs again i checked all fuses and relays and all are good....i need some serious help.

 

[dan lee]

Check your fuel pump relay, see if you have coil voltage for your relay

 

[TJ4Jim]

Was the crankshaft position sensor reconnected to the harness, that's one thing easily overlooked.

 

[Chris]

Seems to me like you forgot to connect something possibly? The fact that it turns over is good, but since it's not firing up it could be one of the two things mentioned above.

 

[Redcow92]

no in fact I put a new sensor on thing it was bad and it is connected

 

[Redcow92]

Check your fuel pump relay, see if you have coil voltage for your relay

all relays are good as are the fuses

 

[Redcow92]

Check your fuel pump relay, see if you have coil voltage for your relay

have voltage at the coil

 

[Fouledplugs]

Have power at the fuel pump?

 

[TJ4Jim]

no in fact I put a new sensor on thing it was bad and it is connected

Did you replace the crankshaft position sensor, if so what brand did you use as the off brands are notorious for being crap.

 

[Redcow92]

Did you replace the crankshaft position sensor, if so what brand did you use as the off brands are notorious for being crap.

mopar part

 

[Redcow92]

Have power at the fuel pump?

yes

 

[derekmac]

If you're getting the key with the slash through it, then I would assume that you have some sort of skim issue.

 

[Redcow92]

does that require a dealer reprogram?

 

[ac_]

Ok you need to narrow down the issue. You engine needs 3 things to run. Fuel, Spark, and Compression. If you are missing any of those things. You rill not start. So to start with check all of those things.


If you have all of those things check all of your pigtails and wiring and fuses. because it is easiest and costs no money. Then check fuel pressure. I am not sure what the spec is but I bet it is at least 60.

But first check for fuel, spark, and compression so we know where to go from there

 

[Redcow92]

Ok you need to narrow down the issue. You engine needs 3 things to run. Fuel, Spark, and Compression. If you are missing any of those things. You rill not start. So to start with check all of those things.


If you have all of those things check all of your pigtails and wiring and fuses. because it is easiest and costs no money. Then check fuel pressure. I am not sure what the spec is but I bet it is at least 60.

But first check for fuel, spark, and compression so we know where to go from there

engine had plenty of compression was running and driving when motor was pulled..my issue is no spark and no fuel....has security key light showing up on dash is why I think the computer needs to be reprogrammed...the wrangler has set for 6 months without a motor or battery in it. Engine has new crank sensor and is getting power to coil pack relays and fuses are all good but not getting power to fuel pump when key is on to charge up the system...engine spins over easily but no ignition spark at the plugs...

 

[ac_]

Wait that is confusing are you not getting fuel and not spark? I am not sure about the sentry key thing, but looking into it a little I found this website that shows how you can do it yourself. It has pictures of a zj but not sure if it is the same for tj. I figure give it a try nothing to loose. But that said if you are not getting fuel nor spark you may have a couple of things going on.

Here is the site I found.

https://www.morris4x4center.com/knowledge-base/jeep-sentry-key-programming.htm

My jeeps have all been too old for that new key sentry, so my knowledge of that is lacking. I am not sure if it stops the computer from spark and fuel but I cannot argue because I simply don't know.

I hope that helps.

 

[Redcow92]

If you're getting the key with the slash through it, then I would assume that you have some sort of skim issue.

winner winner chicken dinner.......after 4 hours at the dealership bad key transponder....980 dollars later do not know why these go bad from sitting but that would keep it from communicating! checked everything but that...Thanks to everyone for the help and comments...no back to having fun!

 

[Chris]

winner winner chicken dinner.......after 4 hours at the dealership bad key transponder....980 dollars later do not know why these go bad from sitting but that would keep it from communicating! checked everything but that...Thanks to everyone for the help and comments...no back to having fun!

I had a feeling that might have been what it was. Good job @derekmac on suggesting it.

 

[Reece]

winner winner chicken dinner.......after 4 hours at the dealership bad key transponder....980 dollars later do not know why these go bad from sitting but that would keep it from communicating! checked everything but that...Thanks to everyone for the help and comments...no back to having fun!

980$ holy hannah.