Long time XJ'ers, I have a question.

Have had the 96 XJ since about November 2015. Bought with 49k on the clock. Everything working fine. Have put about 10k problem free miles on it (80/day).

Throughout the colder months, the start was very consistent. About 3 cranks and a strong start.

About the time the weather got warmer and we started seeing temps in the 60-90 range daily, the startup is a little different. Particularly on the first start of the day, and the start after sitting at the work parking lot all day. It cranks about 5-6 times and starts a little weaker. Enough of a change that it got my attention (I try to pay attention to things like this).

A few facts:
1. No other problems than this
2. Once started everything runs fine
3. No problems during driving at speed
4. Poor man's prime makes no difference
5. Checked fuel pressure after single key-on prime, and it is within spec, and held for quite some time.
6. Startups after quick stops (gas station, stores, etc.) are relatively normal with about 3 cranks and strong start.

A few mornings ago, I took my inductive spark tester and had the wife start the vehicle while watching for spark on the coil wire. Like normal, it cranked a little longer, then started. I confirmed that as soon as the first spark indication appeared on the tester, the engine started at that moment.

So I at least know that fuel and spark are good, and that it starts the moment the spark is introduced, -but- that the spark is being commanded maybe 1-2 seconds later than normal. Other than that, everything is the same.

Questions:
1. Is this just normal?
2. Is this just a warmer weather / thinner air thing?
3. Is it too small of a change to even worry about until the problem develops a little more (if it even is a problem)?
4. Of course its got me thinking about CPS/CKS possibilities, but there are no other symptoms to indicate that these sensors are having a problem. At least for now, it always starts, and always runs fine.

Normally, I wouldn't be that worried about it, but it is my 80/day daily, and I try to stay ahead of problems if possible.

 

Check your battery cable terminals. Mine was sluggish until one of the clamps broke and I replaced them both. It starts fast now.

 

Thank you. Yes that is always the first place to start. I have inspected all connections, and as part of recent maintenance disconnected and refreshed every ground location (wire brush shiny tight).

When yours was sluggish, was everything else operating normally? Was it just the crank time that was effected?

Because there are so few additional variables to go on, and nothing is standing out in the data, I guess I might just have to give this some time to see if it develops into a more obvious problem.

 

There were no other symptoms. And I wasn't even looking to improve crank time. It was an unexpected benefit from changing the terminals.

 

+1 replacing terminals should be your first step.