[mbe25]

i just swapped in a 4.0 out of a cherokee.. (93) into my yj which is a 94 with an aw4 transmission. i have strong spark, good fuel pressure and my question is this..

my injectors are recieving constant power as i crank the engine.. is this normal? it will not start and every time i pull a plug they are soaked in fuel. if you let it sit, it tries to start but then it floods again. i know im getting too much fuel and the timing is right with the came and i dont have any plug wires crossed.. checked them about a million times.


any ideas please? help me! i am going back to school soon and i only get to come home like once every two months to get this thing running.

[yj40swapped]

What type of crank sensor setup did you use? Stock or hesco kit? Yes its normal to have constant power to them... they are ground controlled. A few things I do when I have a engine thats flooded is 1. remove all spark plugs, disable ignition source to prevent spark, crank motor over to remove excess gas, heat up all the spark plugs with a torch on low setting (you can use a lighter if thats all you have) 3. pour a small amount of oil (1-2 cap fulls) into each cylinder to replace the oil that the gas has washed away. and then put everything back together.

Your injectors should be pulsing when you crank the engine. You can test for injector pulse with a test lamp.. known as a noid light. Since youll probably only need a noid light once i wouldnt go buy the set... just use a 12v test lamp connected across both terminals of the injector connector with it disconnect. crank the engine and watched for it to flash.. if its not flashing.. you have a problem.. first place to check would be the crank sensor. With my hesco crank sensor setup... with the sensor removed from the bracket.. I can lightly tap the sensor on the balancer and hear the injectors pulse... that test is done with key on engine off.

[mbe25]

ok i actually am getting the pulse... i didnt realize they were ground controlled thanks..

as with cleaning the plugs and stuff.. i have done that and it just keeps flooding them out.

does any one know if this could be involved in the security system i've heard about with some cherokees? i have had the jeep start for about 2 seconds and it shut off and won't start again.. i dunno..

[mbe25]

oh and it is a stock set up.. rebuilt motor..

[mp3coupe]

The first thing I would check is the dist.

1. Remove #1 spark plug and pull the coil wire off

2. Place your finger over the spark plug hole

3. Have an assistant bump the motor over until you feel air pushing your finger off the hole.

4. Use a socket and manually bring the engine dampener mark to zero.

5. Remove the distributor cap, the rotor should be pointing to #1 cylinder.


report back after you do that

[mbe25]

yeah man, i have done that.. thanks but haha i have done that about a million times second guessing myself..

anyone have an idea? this is only my third build on a motor from scratch. i don't know exactly what i am doing.. my first build with fuel injection... although it is stock im bringing this computer in from a cherokee and putting it in a yj and just lost right now..

[Tomb Raider]

Originally Posted by mbe25

ok i actually am getting the pulse... i didnt realize they were ground controlled thanks..

as with cleaning the plugs and stuff.. i have done that and it just keeps flooding them out.

does any one know if this could be involved in the security system i've heard about with some cherokees? i have had the jeep start for about 2 seconds and it shut off and won't start again.. i dunno..

Mine would do that as well when I had the ECM with the security setup on it. It would crank and try to start...like dieseling...then just crank again. I don't know about the injectors being wet, but I'd sure try to find another one to test out the ECM theory.

-scott

[mbe25]

does anyone know of maybe the specific vin numbers that would come with this? or should i just call the dealer for this.. hmm..

scott- did you have spark, and fuel when it wouldn't start? man that would be great, as i'd simply love to have this thing running. im up in carlisle pa, and im leaving to go back to charlotte for a month but ill be back up here soon enough with some parts. i can only do research from seven hours away haha..oh and parts chasing. luckily i can call up my dad and tell him to try this or that and report back here with my findings.

well time to pack, if anyone has any other ideas, PLEASE let me know. ill have to try this computer thing, as i can get them cheap enough through a "pull-a-part" in char-town.

[Tomb Raider]

Originally Posted by mbe25

does anyone know of maybe the specific vin numbers that would come with this? or should i just call the dealer for this.. hmm..

scott- did you have spark, and fuel when it wouldn't start? man that would be great, as i'd simply love to have this thing running. im up in carlisle pa, and im leaving to go back to charlotte for a month but ill be back up here soon enough with some parts. i can only do research from seven hours away haha..oh and parts chasing. luckily i can call up my dad and tell him to try this or that and report back here with my findings.

well time to pack, if anyone has any other ideas, PLEASE let me know. ill have to try this computer thing, as i can get them cheap enough through a "pull-a-part" in char-town.

Yes, I had everything but a running engine when that security module wouldn't work.

[mbe25]

well thats good news.. maybe ill find a new ecm down here and ill send one up asap.. and ill let you know my findings.. prob won't be back for a few weeks though.

[mbe25]

i am so frusterated witht this thing.

i have:
correct cam timing
correct ignition timing
pulsing injectors
strong spark.
power to all my sensors
good strong fuel pressure
compression

no start.

i am going insane. i have replaced the ecm, the pick up in the dist, the crank sensor and even tried a SECOND WIRING HARNESS!!!!

anyone have any help? on the xj harness/ecm combo, is there anything crazy i need that im not thiniking of to hook it up that i am overlooking just to get the engine to fire? like the speedometer? or something else random?

if someone is bored, i could really use a rundown of what i need to run.. other than timing, compression, fuel and spark. i know that, but i dont know what i am missing.

im so close to hauling it to a dealer but i think they'd just laugh because its a hybrid jeep lol.. half xj half yj. but its gotta get out of the garage, this is going on three years now. i might have to get generous and reward the person who can help me out haha...

thanks,
matt

[atomicmoose]

Originally Posted by mbe25

im so close to hauling it to a dealer but i think they'd just laugh because its a hybrid jeep lol.. half xj half yj. but its gotta get out of the garage, this is going on three years now. i might have to get generous and reward the person who can help me out haha...

thanks,
matt

Well, in that case!

Do you have the 5 wires needed to fire the engine? If not, see TombRaider's thread for detailed info on that.

[mbe25]

I have the five wires. It cranks over but wont fire up?

[atomicmoose]

What's your fuel pressure?

[YJ-Mike]

Go to www.cjoffroad.com, and hit up the 4.0L swap forum there. Spend some time searching and reading, you will probably come across your answer.

When I did my 4.0L swap it was a great resource, plenty of knowledgable people. If it starts for 2 seconds and dies, that sounds like a SKIM (security) module to me, could be wrong though.

Good luck.