Injector issues.

Dedicated forum for all things electrical... Sometimes Electrical issues can really get you stumped! Not Stroker related.
Post Reply
Djmack
Where's the "any" key?
Where's the "any" key?
Posts: 28
Joined: April 22nd, 2009, 5:45 am

Injector issues.

Post by Djmack »

Hey yall, I have been running my stroker with stock injectors for some time now. So, I went on the web and bought some ford 24#/hr injectors. (Note: These injectors are used.)

So, I installed the injectors plugged everything back in, plugged the battery back in after discharging the system, and turned the jeep on. It ran a little rough and threw a code. I double checked my connections and sure enough i didnt press one of the connectors down all the way. After doing so, the jeep ran fine for a minute. I revved the engine up and it began "miss-firing" again, with one of the cylinders not getting fuel. When I went on a test drive, my jeep acted normal through the rpm range the first time up, but when i turned around to do it again, it stuttered, lagged and missed.

Anyway, How do i go about testing all the injectors to ensure they work properly. and whats the cheapest method to test my injector pulse from my system?
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Injector issues.

Post by SilverXJ »

Injectors are clogged. Send them off to get cleaned. Thats a chance you take when you buy used ones.
Djmack
Where's the "any" key?
Where's the "any" key?
Posts: 28
Joined: April 22nd, 2009, 5:45 am

Re: Injector issues.

Post by Djmack »

SilverXJ wrote:Injectors are clogged. Send them off to get cleaned. Thats a chance you take when you buy used ones.
So, under stress the injectors basically choke?
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Injector issues.

Post by SilverXJ »

I didn't read the part about the connector. To see if the PCM is pulsing the injectors use a Noid light plugged into the harness. To see if the injector is working use a mechanic's stethoscope and listen for a clicking, and possibly remove the fuel rail w/injectors attached and make sure its firing.
Djmack
Where's the "any" key?
Where's the "any" key?
Posts: 28
Joined: April 22nd, 2009, 5:45 am

Re: Injector issues.

Post by Djmack »

SilverXJ wrote:I didn't read the part about the connector. To see if the PCM is pulsing the injectors use a Noid light plugged into the harness. To see if the injector is working use a mechanic's stethoscope and listen for a clicking, and possibly remove the fuel rail w/injectors attached and make sure its firing.
i never had a connection problem with my original injectors.. i just did a resistance check on all 6, they all returned the same thing. when the jeep is running, i can feel each individual injector pulsing. Ive looked up some cleaning techniques, so ill be going down to O'Reilly tomorrow to get some things.
CobraMarty
BANNED
BANNED
Posts: 297
Joined: December 3rd, 2011, 2:01 am
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: Injector issues.

Post by CobraMarty »

There is a way to check if your injectors are clogged. You need a fuel pressure gauge mounted on the fuel rail.
-turn on the key to activate the FP and pressurize the fuel rail, watch the FP gauge, turn key of and FP should stay put
-now energize/activate one injector and watch for a drop and how fast a drop in the FP gauge reading
-repeat for all injectors

Better to remove the injectors and energize with a 9v battery and try and blow compressed air thru them. THat might in itself clean/blow it out. Pour some seafoam into them and let them sit overnight and them blow them out with the compressed air.

Maybe it it is still idling rough you can disconnect one at a time the injector electrical connector and see which injector when disconnected doesn't change the rough idle-that is the bad one. A good injector will make it idle worse.

You can try a can of seafoam in the tank or other fuel injector cleaner. I wouldn't run with a clogged injector.

Sending them off to get cleaned is the best, but expensive. Like said before, That is the problem with buying used.
1998 XJ 2D AW4 32"MTR 3.55 4.5"RC JCR Slider Magnaflow 150rwHP/174rwTQ=> Sprintex SC Gibson Header 6lb 120-140*IAT 211rwHP/274rwTQ WasherFluid Inj 70mmTB 7.5lb 100-120*IAT=>Now 12 pounds Boost=> +BV ported head
99 XJ M62 S/C
Djmack
Where's the "any" key?
Where's the "any" key?
Posts: 28
Joined: April 22nd, 2009, 5:45 am

Re: Injector issues.

Post by Djmack »

I ended up cleaning my injectors as seen in this picture. I did notice that my harness connectors have an intermittent connection, is there any convenient way to ensure connection with out having to rip them all out and solder in new ones?

Image
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Injector issues.

Post by SilverXJ »

You could try zip ties.
Djmack
Where's the "any" key?
Where's the "any" key?
Posts: 28
Joined: April 22nd, 2009, 5:45 am

Re: Injector issues.

Post by Djmack »

SilverXJ wrote:You could try zip ties.
they're all pushed down, but its like the metal compression clips inside the plugs have to large of a gap. i've repaired a couple with foil.
User avatar
SilverXJ
Global Moderator
Global Moderator
Posts: 5789
Joined: February 14th, 2008, 7:14 am
Stroker Displacement: 4.6L
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Radford, Va

Re: Injector issues.

Post by SilverXJ »

For reliability and engine life you will want to replace those.
92tank
I made it to triple digits!
I made it to triple digits!
Posts: 188
Joined: August 21st, 2010, 6:32 pm
Stroker Displacement: 4.5
Vehicle Year: 1992
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: Injector issues.

Post by 92tank »

or you could try a small pick and bend them closed, or if you can get them out of the holder you can do the same
Djmack
Where's the "any" key?
Where's the "any" key?
Posts: 28
Joined: April 22nd, 2009, 5:45 am

Re: Injector issues.

Post by Djmack »

Well, I'm to lazy to take apart each connector.. So, I dabbed a little solder on each injector pin and pushed the connectors back on, pretty snug fit, I test drove it. so far so good.
Post Reply

Who is online

Users browsing this forum: No registered users and 10 guests