XJ doesn't like Ford injectors

I put these in last week (F4SE-A1B, 0280155700) and at first it seemed to take them fine. I reset the computer and all hell went loose. I had an erratic idle that cycled between 1000-750 RPMs. I thought it was a vac leak so I went over the whole system with a vac hose. Found one or two of them and seal it but way too small to change anything. I seafoamed it next thinking the injectors might be clogged. No affect though I did get a great smoke show. I checked the TPS with the voltmeter. Getting .800 V to 4.09 V. A bit under the range but it shouldn't affect it much. So I finally decided to swap back to the old injectors and now it idles perfectly. I don't get how lots of other Jeeps love the Bosch's but mine hates them. I tested the ohms on each of the injectors and they were between 14.2 ohms to 15 ohms. I couldn't find any info on what is acceptable for these injectors but it seemed to be close to 5% error in my guess. Any ideas? This is for my 98, 5 speed, 231. Has a swapped 99+ manifold if it matters.

new, used or rebuilt injectors?

These are used. Got them off ebay. Seller claims they have about 66k miles on them.

Possibly clogged open or closed. Did they smell like stale gas? However, they flow a bit less than stock. They are 19.4lb @ 3bar. Which would equal 20.6lb @ 49psi. Your stock injectors flow 23.2lb. That little bit shouldn't effect the idle though.

I'm running the Ford injectors on my RENIX. No issues with the way my Jeep runs but I do have hot-soak issues with them (#3 & #4). This does not happen with the stock injectors, only the Fords.

I bought new Ford injectors.

Forgot to mention, it only does it when fully warmed up. I believe that as soon as it switches over to closed system, the erratic idle begins. These injectors are the newer EV6's with the EV1 connector. From my understanding, the EV6's are more resistant to heat soak issues.

Also how would I test for stuck injectors?

Those injectors work out to 21 lbs when your PCM is expecting 23 lbs injectors. Don't know how much of a difference that would make though.

Oops.. didn't realize I already posted this.

Have you checked your fuel pressure?

No, I didn't think I needed to since she runs fine with stock injectors.
I'm thinking of putting them back in and running BKG44 through it instead of seafoam.

If they are very clogged no in tank cleaner will touch them. You may have to send them off for service. There are also those on car services that just run the cleaner through them via the fuel rail check port. While still not as good as a off the vehicle clean, it is better than the in tank stuff. I am unsure how to check them aside from pulling the coil rail and seeing if the spray patterns are odd or if one is leaking down.

crimsondragon said:

No, I didn't think I needed to since she runs fine with stock injectors.
I'm thinking of putting them back in and running BKG44 through it instead of seafoam.

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BG44K FTW

Talyn said:

If they are very clogged no in tank cleaner will touch them. You may have to send them off for service. There are also those on car services that just run the cleaner through them via the fuel rail check port. While still not as good as a off the vehicle clean, it is better than the in tank stuff. I am unsure how to check them aside from pulling the coil rail and seeing if the spray patterns are odd or if one is leaking down.

Click to expand...

That seems redundant as I've seen injector cleaning services go up to about $24 an injector. I'll give the 44K a try and if it doesn't work, these injectors will go in the trash. Thanks.

Just curious, but why would you swap in 66k mile injectors?

muddeprived said:

Just curious, but why would you swap in 66k mile injectors?

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Injectors rarely fail. They get dirty but they rarely fail.

You need the blue bosch style injectors for an HO. They yellows one people put in a RENIX won't work. Been there done that. Once I got the blue injectors I was still getting intermittent idle problems. It turned out I wasn't getting a good electrical connection on the injectors. I swapped out the connectors with ones off a newer XJ and that took care of the problem. Your '98 might already have the newer connection.

I run the yellow Ford Injectors in my RENIX truck, no problems at all. In fact, a noticeable gain in performance over the original(and dirty I'm sure) OEM injectors. Bought them on eBay for about $75, rebuilt, flow-tested, and matched. And the same vendor has the ones you may need. Read this auction listing, there is a ton of info in there:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=250730140366

Have you driven it at all? In my experience the ECU takes some time to learn and adjust long term fuel trims.