Starting problem on my 91XJ

I was just wondering if someone had an idea what to look for in this problem. When i start my XJ no matter if it is warmed up or not it takes about 10-12 sec to start and then it is rough for a second or two . It runs like a top once it is running, could this be a fuel filter problem ? I just bought it a couple of months ago and still workin the bugs out. It only has about 96,xxx miles ...................Help please

XJ_99 said:

I was just wondering if someone had an idea what to look for in this problem. When i start my XJ no matter if it is warmed up or not it takes about 10-12 sec to start and then it is rough for a second or two . It runs like a top once it is running, could this be a fuel filter problem ? I just bought it a couple of months ago and still workin the bugs out. It only has about 96,xxx miles ...................Help please

Click to expand...

They are slow to start, 3-4 seconds is normal. Have you actually timed it? Do you wait for the fuel pump to stop before starting it? Coild be a little bit of wear and age on a number of parts and connectors in the entire igniton system. What year is it?

Ecomike said:

They are slow to start, 3-4 seconds is normal. Have you actually timed it? Do you wait for the fuel pump to stop before starting it? Coild be a little bit of wear and age on a number of parts and connectors in the entire igniton system. What year is it?

Click to expand...

The year's in the thread title. :shhh:

I'd certainly start with a fuel filter if you don't know its history. It's cheap and easy to do.

Wait until the fuel pump stops humming, or even cycle the key to make it go a second time before cranking. If this improves start time it's symptomatic of a leaking check valve. You can live with this or fix it.

Check for black smoke and stumbling on start. That could mean a dribbling injector flooding one cylinder.

Check the fuel pressure regulator. A recent thread with a similar problem ended happily with a new one of these.

Slow starts on any XJ always bring up the crank position sensor as a prime suspect. As I recall, the 91 is a little different from all others before and after, and I don't have the instructions for testing it, but someone must.

I think this is a problem with a charcoal canister or some time of issue like that. This is not the uncommon, keep searching, and see if someone smarter than me pipes in. There is a pretty common and easy fix for this.

Hey guy's thanx for all the info and I think I will start where Matt told me to and go from there . It does stumble for a sec when it starts but then kicks right up and runs fine................

thanx Tony

easy way to check if it is the check valve in the fuel pump is to hook up a fuel pressure gauge and check fuel pressure. my 92 was doing the same thing,and fuel pressure would drop as soon as the fuel pump stopped running. I put a new pump in and it holds pressure now,and starts in less than 3 seconds most times.