Precision Auto Injectors.. now hard start

I had heard good things about these injectors. I bought the set for the 99-04 4.0L. Ever since installing them my Jeep has started hard, even when warm. I have a feeling they are leaking and causing the hard start, since it seems others have had this problem. Once the Jeep is started it runs great and has better throttle response.

I'm going to rent a fuel pressure gauge tomorrow to test the fuel pressure, but even if one of them is leaking how would I find which one?

Is it possible to remove the fuel rail, pressurize it (without starting the jeep) and seeing if they leak? (having lots of rags handy obviously)


They have a lifetime warranty and I'd like to try to fix the issue before throwing in the towel and returning them.

Thanks!

When I bought mine from Precision, the Jeep ran like crap. I returned them and they sent me a new set, which have been fine.

did you lube the o-rings before putting them in?

fallacist said:

did you lube the o-rings before putting them in?

Click to expand...

I did. I guess I'll try giving them a call and seeing what the deal is.

I got my injectors from a dude on another jeep forum. His email is [email protected] Great price, quick shipping, knowledgeable, and they worked just fine for me.

I called them up today and he is sending me a new set. We will see how well the new ones work.

seems to be a very common problem with percision injectors....first set sucks...second set fixes the issue....read that countless times throughout the forums

I've had mine in for almost 2 years and I couldn't be happier with their performance.

Hopefully your second set works as expected.

Here's our experience with Precision Auto Injectors.

http://www.jeepforum.com/forum/showthread.php?p=14810729#post14810729

We get it you had a problem, but do you really need to search out every single thread about injectors and post your problems? Even on other forums?

I ordered a set and they were junk. Raw fuel vapor pouring out the tailpipe. Reinstalled the old ones and no problem. Installed the new set, smoked again. Emailed Precision and they said they would make it right. That was the last time they replied to my emails or phone messages (and yes, I was polite... Sh*t happens with stuff right out of the box some times). Fortunately I used PayPal and was able to get my money back through them. Cannot recommend them.

I bought a used set off here. They run fine and all, maybe a little quicker and better startup but other than that, nothing else. MPG stayed the same, didn't really feel anything on the butt dyno. They might be a good buy for failing injectors but if you don't need them, don't bother. Try some remanufactured Bosch or Neon injectors.