I could really use some help. I have a 96 4.0l Cherokee xj sport inline 6 2 wheel drive. I "upgraded" my fuel injectors with 4.0l Ford Ranger 4hole injectors because I could not aford the neon injectors at 130$ a piece. Now my engine is not starting and I was wondering if it is just not ok to use these injectors or if maybe I need to change the spark plug gap or something to adapt to these new injectors. It is trying to turn over but gives out before it starts and sometimes I get a little puff of a back fire noise that sounds like it is rushing into my intake more than my exhaust because it is muffled not a loud pop. I'm just becoming very frustrated because I've been working on this thing for a week straight doing a full top end rebuild and the injectors are the only thing that I have changed. (V15169 or 57081 bwd injectors.)

 

Was there anything wrong with your stock injectors? Can you swap them back in and see what it does?

 

Which injectors are they, (Part Number)?

Never heard of using ranger injectors?

There are always plenty of people here on the forums selling the re manned upgrade injectors for around $60 a set of 6.

 

From what I can find the flow rate on the ranger injectors are not enough for the Jeep 4.0. Look at the links.

This is the Ranger injector.

http://www.witchhunter.com/flowdatapix/b0280155962.jpg

This is the Jeep "Upgrade" injector for your year.

http://www.witchhunter.com/flowdatapix/b0280155703.jpg

 

I posted the part number off the injector box. Yes I have the original oem injectors and no nothing wrong just trying to save fuel economy and get a better burn. Well I hoped since the injectors are for a 4.0l engine it would have the right psi/cc for spray.

 

So I put the oem fuel injectors back in and no change. Double checked the spark plugs and I am getting a spark and the gap is spot on and you can smell the fuel on them so I'm at a loss… what could it be if I'm getting both fuel and spark… even tried a little starting fluid to just try and get it to fire for even a moment and nothing.

 

Sounds like you're getting a ****ty spark. Can you verify that you are getting a good strong blue spark on all plugs?

 

Maybe accidentally flip flopped injector connectors?

 

Describe this in a little more detail.

 

Could the camshaft timing be off? Sounds like what you are describing. No way would those injectors prevent it from starting. Might not be optimum to use them though. The spark plug gap is fine too reguardless of different injectors.

 

OP, no offense but you really should have done research first and we could have saved you this issue. Time to go back and check all your work. See if you hit any wires. Check you plug orientation. Tightness, etc. Rent s gas pressure gauge. Simple troubleshooting will get her back on the road. Could just be a dumb coincidence. And yes, there's vendors here that sell cheap remans, which is what you'll want to get

 

All my connection's are good. It could be timing but I did not mess with any of that. This all started with a head gasket leak. I pulled the head and had it machined and cleaned at slacks auto new push rods and liffters. I think maybe I did not seat two push rods correctly and now I'm not getting compression on two cylinders. Four cylinders is not enough to fire if I have valves being held open right? Sorry I'm new to this first time jeeper and the bug bit me bad to build it on my own. I have the complete crystler technician manual set for it so I'm not flying completely blind, way better than an Haynes.