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My Jag has a seventh fuel injector that only adds fuel when the engine is cold, and I think it was making the car run way too rich.
When I start my Jaguar, it runs rich. That is normal until a car warms up, but this one runs really rich and the engine bogs down when you get on the gas while it is cold. I’d already replaced the coolant temperature sensor. My theory was the cold start fuel injector, a seventh injector that dumps extra fuel in when the engine is cold. It might be leaking or not shutting off. So I ordered a new one and a gasket and swapped it. The injector is specific to the car, so the button goes to the kind of long Torx bits that made the job easy.
- Easy job once you have long Torx bits
- No need to remove the mass airflow meter
- Old injector came out cleanly
- New part looked the same as the original
- The injector sits deep under a rat’s nest of hoses
- Parts can be hard to find; mine came from Australia
- Cold start injector is specific to the car
▶ Watch the full review on YouTube
What a cold start injector does
Most engines have one injector per cylinder. Mine has six, plus a seventh big spray injector called the cold start fuel injector. It adds extra fuel when the engine is cold.
If it leaks, puts in too much fuel, or doesn’t shut off once the engine warms up, the car can run rich and bog down, which is exactly what I was seeing.
Getting it out
It is not in the easiest place. It sits way down under a bunch of pipes and hoses, held by T30 Torx screws, with a fuel line and a clip on it.
I bought a set of long, deep star bits. They reached almost all the way down, fit nice and tight, and with a socket I got the screws out without disassembling the mass airflow meter. Small hands help.
Old versus new
The old one says Lucas on it, so it could be the original part. Someone in the comments said they got theirs from Australia, and so did I. The new one looks like generally the same part, and I put in the new gasket too.
I joked that this would be the hardest job ever, with rusted nuts and stuck hoses. It turned out to be simple and quick, and I didn’t have to take anything else apart.
About the buy link
The video’s link went to a general Amazon auto parts page, not a product, and the Lucas-style cold start injector for my Jag isn’t sold on Amazon. The button goes to a 6-inch long Torx bit set (T6 to T40, including T30) like the long star bits I used. Get the injector itself by your car’s part number.
Did it fix it?
It fired up and runs, which is a good sign. It should still run a bit rich when cold, just not as rich, and any dripping from the old injector should be gone.
Get the long Torx bits before you start. They made a whole bunch of difference.
FAQ
What size Torx bit holds the cold start injector?
On my car, T30.
Do I have to remove the mass airflow meter?
I didn’t. Long Torx bits and a socket let me reach it.
Should I replace the gasket?
Yes. I bought a new gasket along with the injector.
Where did you get the injector?
Mine came from Australia. It is specific to the car, so check your part number.
Is this an affiliate link?
Yes. The buttons are #ad affiliate links, and as an Amazon Associate I earn from qualifying purchases. It costs you nothing extra.
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