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help i need as much information about the renix fuel injection and vacume lines route

troublesome89xj

NAXJA Forum User
Location
whitehall
hey guys i have a 89 with the 4.0l and the motor has been rebulid but now i have a miss in the motor it starts up fine and idles fine but as soon that you want to go faster and hit the gas its begins missfireing and stubling and the occusasional backfire so im wondering if any body can help that will be great and i also need to know that are the man componets of geting the renix fuel injection system to work correctly and also need to know the vacume line routeing diagrams this xj is a 89 with the AW4 trans with 231 transfer case PLEASE HELP!!!!
 
Re: help i need as much information about the renix fuel injection and vacume lines route

ok I know what your problem is
Whoever installed the distributor indexed it wrong.Remove it and reinstall it back or fowards one tooth on the dist. drive gear.It will take a little trial and error to get it right,but when you get it stabbed right you'll know.
I'm 99% sure that is whats wrong....
Do a search on distributor indexing for more info.....The just of it is that if your #1 cylinder is at tdc the rotor button should be just starting to point at the #1 plug wire inside the cap
 
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Re: help i need as much information about the renix fuel injection and vacume lines route

A long screwdriver can be used to rotate the oil pump so the end of the distributer shaft will "stab" in correctly.
 
Re: help i need as much information about the renix fuel injection and vacume lines route

well i have done that so many times to index the distrubor i about to shoot my self because i get it right on from what i can tell and then you give it fuel it misses i dont know what the heck is going on!!!!!
 
Re: help i need as much information about the renix fuel injection and vacume lines route

Here's a Renix vac diagram if that's still possibly a problem. To me it sounds like your problem is more timing related though like those guys said. Actually it really sounds like a CPS to me, before you try to reindex the dizzy and frustrate yourself more I would try a CPS.
RenixVacDiagram.jpg
 
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A funky, bad TPS will cause it too.

Also, check that the TPS and O2 sensor connections at the wiring harness are not backwards, Pin A must be connected to Pin A. If oin A is connected to Pin C it will act the same way. And the vacuum line from the throttle body to the MAP sensor must be in place and not leaking any at all!

On the CPS topic, I had a thought last night. I got wondering if running shielded wires from the CPS to the ECU might extend the useful life of the CPS? There was a discussion recently about a capacitor helping an old dying CPS live and work longer.
 
Re: help i need as much information about the renix fuel injection and vacume lines route

could be a bad fuel pump or clogged filter. if the distributor is one tooth off it will sputter and pop when you rev it in park. under load while driving, it may not be getting enough fuel.
 
Just disconnecting the TPS and then giving it gas will cause those symptoms.

If you are truely satisfied the Distributor is set right, the TPS and the CPS signals can be tested with volt meters. There are several good threads and write ups in this forum on how to do those tests with digital and analog multimeter. Just search TPS* CPS* and Renix, also "ReniX Files" thread has some usefill tips.

troublesome89xj said:
hey guys i have a 89 with the 4.0l and the motor has been rebulid but now i have a miss in the motor it starts up fine and idles fine but as soon that you want to go faster and hit the gas its begins missfireing and stubling and the occusasional backfire so im wondering if any body can help that will be great and i also need to know that are the man componets of geting the renix fuel injection system to work correctly and also need to know the vacume line routeing diagrams this xj is a 89 with the AW4 trans with 231 transfer case PLEASE HELP!!!!
 
Re: help i need as much information about the renix fuel injection and vacume lines route

Did you get it figured out?
I would think that if his map was leaky/bad he would'nt have a good idle at all....
 
ok so my 88 4.0 is doin the same thing

idle is very good. rev it up and it sounds and runs fine

under load its all sputter and no power, but thats when i get on it, if i ease into it its slow, but it does get up to speed.

any thoughts?
 
not to jack the thread but i found something interesting out. if i disconnect the vac line to the fuel presser regulator and take it for a spin, i have my power back! the idle goes up about 700 rpm in the test.
 
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not to jack the thread but i found something interesting out. if i disconnect the vac line to the fuel presser regulator and take it for a spin, i have my power back! the idle goes up about 700 rpm in the test.

without the vacuum line, the fuel pressure is at its highest, 39psi. so either the regulator is bad or your fuel pump is on its way out. get a fuel pressure guage and test the fuel pressure and regulator. haynes or chiltons has a procedure to check the pressure and regulator with a gauge.

did you check the fuel filter?
 
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