I have a little BMW club car (cheap registration and insurance but limited use in my world). I have been working through a bunch of issues with and learning a lot along the way.

At first the car was very, very hard to start when hot (purchased in summer). It would struggle to start and run and felt to me like it was flooded, and would finally clear with some more throttle. Over time this has gradually improved to the point where if you give it quarter throttle when hot, it will start ok (its a 94 so still has a cable throttle) Cold start is perfect every time. All other aspects are running and driving are fine these days.

Related things already done in general work and pursuing this issue:

Fresh fuel
Injectors cleaned and tested (suspected leaking injectors)
Fuel pressure regulator replaced (cause the injector shop said that's what they see more of)
Temp sensor and knock sensor replaced (found with rotted wiring and connections under replaced bit of cooling plumbing)
Checked plugs and found them in good condition and evenly colored (thinking of leaking head gasket)
Swapped the MAF (spare came with car)

There are some more sensors to be replaced either in parts canon or preventative maintenance mode (depending on what story I am telling myself)

Any thoughts or experiences with hot starting you can share?

 

yarpos, I would be looking at the fuel system. You may have say a fuel pressure regulator that is drifting in temp when it gets hot. So, the situation would be you turn off the car, everything under the hood gets up to about 150F (maybe more). This causes a spring or something of the like to get weak and drift the pressure that the fuel regulator is trying to maintain. When you go to start, the pressure is not too low. Your cylinders are now not getting sufficient fuel to start the car. Stepping on the gas pedal introduces more fuel and also pushes "cold" fuel into the regulator (bringing the spring back to where it needs to be, raising the pressure), allowing the car to start. Now, because you have the "cold" fuel flowing through the regulator, it can keep the spring where it needs to be. I have seen some strange problems like this. I would say to monitor your fuel pressure on start up and see what happens.

The other "trick" that I would say to try is to roll the key to the RUN position when starting the car, let it set there for a few seconds and then finally roll the key to the START position. This will allow the pressure to build up and potentially help the car start. If this trick works for you, then your fuel pump is on its way out most likely.

 

Thanks for the input. I will try some of that. The regulator has been replaced but that doesnt mean I got a good one.

 

Steve:

I came across your post explaining how to simplify XJ6 S3 headlight wiring.
I have a 1983 XJ6 with a crate ZZ4 making about 385 HP.
Somehow, the lighting has stopped working and I thought it time to get rid
of the Lucas wiring.
I'd very much appreciate your help so that I may fully understand your set-up.

Thank You,

James

 

My headlight wiring is almost totally stock. Very little has changed in the wiring.

I have done three things:

1. Changed what the headlight switch does. Instead of carrying high current to the headlight relay it now just switches a standard 4 pin relay that I placed next to the headlight relay. The new relay then provides headlight current.

2. I replaced the headlight relay

3. I added a LED light bar to the front, but that was all additional and did not change the headlight wiring

It would be better to start a thread in the XJ6 forum and get more eyes on the question. There may be people there who have done what you want to do, or can help resolve the initial problem.

 

Thank you. That actually clears some things up for me.