Issue after 5.0 injector swap...

Installed the set of 5.0 injectors that I bought from 5.0 motorsports a few months back. The injectors went in and out without any trouble at all. I had swapped in a single injector about 6 months back due to it leaking, but a few weeks later I found another leaky injector so I bought a whole set of the 19lb 5.0 ford injectors. So I got everything back together and went to crank it over but no fire.

It sounds as if its trying to fire on one of the six cylinders, but it just wont go for the rest. I get fuel to the rail but I do not know if the injectors are firing or not. I know you can listen to them with a tool of some nature, also heard you can use a screw driver somehow.

There are not any mods i need to make to the injectors to allow them to work with the jeep ECU right? I have an 89 XJ, more or less factory motor. The injectors I got were the orange and black ones. Is there a way to see if I got the right injectors?

There is no leaking gas or anything around the openings (top and bottom of injector) so I dont think its an issue.

I may get a chance to tear into it tonight...so any ideas would be cool.

Thanks,

-Scott

Are you sure you reinstalled the injector harnesses correctly? If they're not clipped all the way down then you wont have any fuel.

Also check/re-check any harnesses or lines you might have disconnected. Like the IAS, TPS & MAP sensor harnesses.

You can take a wooden dowel or long screwdriver & place one end on the injector & place the other end in your ear, this'll allow you to hear what it's doing.

-jb

Fuel injection sucks. Get a Holley Double Pumper.

CRASH

19# injectors are a direct swap should be no problems if you connected them properly. Are all the spark plugs wet? did you flood it when trying to start?

I just did this mod yesterday. Direct swap worked perfect. If you have an ohm meter they should read 14-17 ohms ( acrosst the connectors of the injector itself ), other wise you can hook them to 12 volt and when you apply power they should click. Another test is to back probe the connectors with A 12 volt light, watch for it to flash rapidly when you crank. Search the number stamped on the injecter might be fote-xxx00 plus a number or a number starting with 0280 good luck..... ps shot in the dark if the vacum hose to your map sensor on firewall is broke or unhooked makes for a nasty sounding engine

Obviously, he mixed up the harness connections to the injectors.

Just like spark plug wires, they need to fire off in a given order. He's got the "injector timing" screwed up.

Check the FSM- you'll see the color codes for each injector

burntkat said:

Obviously, he mixed up the harness connections to the injectors.

Just like spark plug wires, they need to fire off in a given order. He's got the "injector timing" screwed up.

Check the FSM- you'll see the color codes for each injector

Click to expand...

I thought ahead on this one

I labled them all before I pulled off the metal retainers to pull the plugs off. I know the right plugs are on the right injectors.

I have not gotten a chance to test anything out, as its dark by the time I get home. I should get into it this weekend.

-Scott

just curious...what are the advantages of swapping in the 5.0 injectors? Is it a performance issue? this is the first of heard of this. thanks

totaledXJ said:

just curious...what are the advantages of swapping in the 5.0 injectors? Is it a performance issue? this is the first of heard of this. thanks

Click to expand...

They supposedly have a finer dispersion pattern that some people think promotes a more complete burn, but the real advantage is that you can find them a lot cheaper than the OEM replacements for the XJ. And often you can buy a set of 8 (as for a Ford V-8) for less money than you'd pay for six of the "correct" injectors, giving you a full set of replacements plus two spares.

i just did this swap this past weekend. i too got mine from fiveomotorsprorts.com. they were orange and black. no problems here. like someone said, check the wiring or any other harnesses that you might have undone. i also labeled mine to remember were they went.

A lot of us run the Ford 24# injectors to give more fuel when we do a stroker conversion and increase the displacement.

Which ones do you use, they got a bunch of them for the 5.0L....

Back from the dead....


Ok guys, I got a chance to get back into the project this morning. This is what I've found out. The injectors connectors only appear to be getting 3-4 volts while cranking. According to my factory service manual and everything else i've read, they need to get 12v. I have check all of my connections and everything seems to be connected well. I also attempted to use a 12v test lamp on the injector connector and it would not light.

I can not seem to find a flowchart for troubleshooting this in the factory service manual.

I did check the resistence in the injectors and they were with in spec. 16.8 ohms for the factory injectors and 14.3 ohms for the 5.0 injectors. The FSM states that they should be 16 ohms +- 12.

I have a feeling i'm missing something here. Anyone have any ideas?

-Scott

Try checking the grounds on your engine, I had a crappy running motor for a while, I searched the forum for a while and came across suggestions to check the ground wires as this will create low voltage to the engine wiring harness. The two spots to check are where the oil dipstick attaches to the block and the ground strap that goes from the firewall to the cylinder head. remove and clean all the connections, use a wire wheel or something to get it all nice and shiny, really helped my engine run better. HTH

Josh