Fuel injectors help
02-21-2017, 02:33 PM
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Fuel injectors help
This is my first post so bear with me! I've done a ton of searching and can't seem to find a good answer to the issue I'm having.
2 weeks ago I bought a 96 XJ 4.0, 220k miles, everything in rock solid shape. First things I did was the fuel injector swap along with fuel filter, air filter, distributor cap and rotor, plugs and wires. Reset the PCM and followed all of these swaps from the DIYs written up. My XJ is still running a little choppy and throwing some misfire codes. Runs great when I give it some gas and when cruising- for the most part.
Idles at 741 and starts right up. However, when initially giving it gas it's a little choppy and in 3rd gear going 45 mph it's super choppy. I took the injectors back out, cleaned the bays and re-lubed the orings. Plug wires are in correct orders. I can't for the life of me figure out what's going on. Any help would be greatly appreciated!
2 weeks ago I bought a 96 XJ 4.0, 220k miles, everything in rock solid shape. First things I did was the fuel injector swap along with fuel filter, air filter, distributor cap and rotor, plugs and wires. Reset the PCM and followed all of these swaps from the DIYs written up. My XJ is still running a little choppy and throwing some misfire codes. Runs great when I give it some gas and when cruising- for the most part.
Idles at 741 and starts right up. However, when initially giving it gas it's a little choppy and in 3rd gear going 45 mph it's super choppy. I took the injectors back out, cleaned the bays and re-lubed the orings. Plug wires are in correct orders. I can't for the life of me figure out what's going on. Any help would be greatly appreciated!
02-21-2017, 02:59 PM
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Junkyard injectors or purchased as tested?
I'd throw the original injectors in as a test. Unless you gapped the plugs wrong or used Bosch +4 or something.
I'd throw the original injectors in as a test. Unless you gapped the plugs wrong or used Bosch +4 or something.
02-21-2017, 07:33 PM
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I've triple checked the plug wires and they're in the right spots. Cleaned the IAC and throttle body and replaced the gasket. As far as the injectors, I picked them up on eBay here: http://www.ebay.com/itm/112189814638...%3AMEBIDX%3AIT
I looked into these injectors and didn't see any kind of negative feedback so I went for it. And of course I threw the old injectors away right after the swap like an idiot.
I looked into these injectors and didn't see any kind of negative feedback so I went for it. And of course I threw the old injectors away right after the swap like an idiot.
02-21-2017, 09:25 PM
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Take a long handled screwdriver. Run the engine. Hold the metal tip of it to the injector body. Hold your ear to the handle. You should hear a fast even ticking. Doesn't rule out clogs or fuel pressure though. But it's a cheap start.
02-21-2017, 10:56 PM
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"703's" should be fine there.. "0280155703 .,0280155703-6R" no idea on the other "6R" I don't know what the 6R means.
https://www.polog40.co.uk/article_injector_table.php
https://www.polog40.co.uk/article_injector_table.php
Last edited by DFlintstone; 02-21-2017 at 11:03 PM.
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02-23-2017, 10:52 AM
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My computer is pulling codes for misfires on all 6 cylinders as well as a gas smell from the engine bay and crazy bad gas mileage. No leaks from the injectors- looks like these things are toast. I have some new ones coming so hopefully that will solve the issue!
02-23-2017, 03:48 PM
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Is his map on the TB or the firewall?
Jeff, if your MAP is on the firewall< (green connector) >>
There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage and it will be pig-rich. (maybe black smoke, fouled black plugs). You can pull the line off the MAP and feel for vacuum with your finger. If it runs!
Jeff, if your MAP is on the firewall< (green connector) >>
There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage and it will be pig-rich. (maybe black smoke, fouled black plugs). You can pull the line off the MAP and feel for vacuum with your finger. If it runs!
Last edited by DFlintstone; 02-23-2017 at 08:55 PM.
02-23-2017, 04:40 PM
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I'll give it a look when I get in there tomorrow or Saturday. Thanks for the advice! The eBay seller didn't hesitate when I initiated the return so it doesn't sound like it's the first time they've gone down that path. Got some legit injectors on the way (I was hesitant buying the first injectors, should've trusted my gut)
02-23-2017, 08:59 PM
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It's tough to change injectors without mucking up the MAP tube, if you have one. 97 on, I think it's on the TB with just a little "elbow" feeding it's vacuum. Before that is a brittle little tube from the TB to the MAP back on the firewall. Very crucial that MAP. It makes the first stab at injector pulse width based on your right foot. As you open the throttle plate vacuum drops, telling the MAP to tell the Puter' to send more fuel. After that finer stuff kicks in, like the O2 sensor and temp ect. If the MAP is out to lunch, all else is screwed.
Last edited by DFlintstone; 02-23-2017 at 09:22 PM.
02-23-2017, 10:28 PM
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It's tough to change injectors without mucking up the MAP tube, if you have one. 97 on, I think it's on the TB with just a little "elbow" feeding it's vacuum. Before that is a brittle little tube from the TB to the MAP back on the firewall. Very crucial that MAP. It makes the first stab at injector pulse width based on your right foot. As you open the throttle plate vacuum drops, telling the MAP to tell the Puter' to send more fuel. After that finer stuff kicks in, like the O2 sensor and temp ect. If the MAP is out to lunch, all else is screwed.
Side note, I've got a brand spankin' new o2 sensor in and my comp is still pulling the p0141 code and my temp gauge never gets to 210 (these issues were present before I started tinkering). I was planning on changing both coolant temp sensors and the thermostat this weekend for good measure. Sounds like the MAP may be the culprit.