My 8v Mk1 runs bad when the oil temp hits 100 cels

[Danny]

So could this be an issue with a bad thermostat. I've changed the warm-reg, aux air valve and almost everything else with no resolution.

Run perfect when the engine is cool. Some one please help!
 Wheres Super rubjonny when u need him?

[rubjonny]

I wouldnt have thought so, but you can check it easily.  Run the engine from cold and feel the bottom hose, it should stay stone cold then get hot when the temp guage gets to about half way.

What are the symptoms, and do they get better/worse if you unplug the 5th injector and/or WUR?  I haven't played with a K-Jet motor yet, so I'm not too hot on them.  Will change soon hopefully as I've got to put one in my cabby project

[Danny]

I replaced the 5th injector/ WUR. There brand new. Could that still be it?

I live in Florida... Its really hot over here. The car runs fine in the beginning(when cold). If I get stuck in traffic or drive the car to long, the engine starts to miss on acceleration.

I barely make it home.. Put..put...putting..exaust almost backfiring. Let it sit the rest of the night and its fine again in the morning. Then it all happens all over again.

I've been posting this problem for months with no solution.

I've replaced the warm-up reg, cold start valve(5th inj.), aux air valve, checked for vacuum leaks(none), change the air filter, fuel filter, no rust in filler neck. And running 0-40 oil(rec. by bosch)

Could it be the oil cooler being bad. Has anyone heard of the car running bad cause of oil temp and having the same symptoms?

Whats is it!!!!? Maybe thermostat stuck or need Hot climate thermostat? Maybe the timing.<--- runs fine when cold) so...?

[rubjonny]

The std thermostat should still cope, and 100 degrees C isnt hot by any means!
Have you noticed the car pinking under load, and overrunning when you turn off the ignition?

[Danny]

No. Doesn't over-run. Dont know what pinking is but I guess its the same.

I read somewhere that if the fuel lines are to close to the engine, the gas gets "super-heated" , and can cause some trouble. Have you ever heard of that?

So have any ideas? Should I get my fuel pressure tested? I haven't changed the fuel pump. It whines pretty loud. How loud is to loud? Should I be able to hear it from inside the car when I'm shut inside? Cause I can. Its loud.

Does the engine use less fuel pressure when cold and require more pressure when hot. Or is it set to one setting at all temperatures?

[rubjonny]

pinking is 'pre-ignition' or pinging/knocking:
http://en.wikipedia.org/wiki/Engine_knocking
Have you had the ignition timing checked, and/or have you tried higher octane fuel?

When cold the engine will require more fuel pressure, as the pressure determines how much fuel will be added to the mixture and when cold cars need more fuel to run right.

[Danny]

Yeah! It pings. I can hear it. What should I do? Is that the ignition timing?

[rubjonny]

Yes normally, it can also be caused by low octane fuel (if the ign timing was set up for higher octane fuel) and hot spots in the cylinders caused by excessive carbon buildup.
First thing to try is back off the ign timing a little, if you need to take it lower than the stock timing, then something isn't right, either you have really low octane fuel or carbon buildup, or a problem with the fuel mixture.

One thing you can do for carbon build up, is allow the engine to suck up water, it vapoourises in the cylinders under combustion and steam cleans them
Its tricky on fuel injected engines though, if it was a carb you just trickle it down the choke flap.  What you can do is unhook a vacuum line from the throttle body and imerse it in water.

While you do this hold the revs up, as it will start to bog down.  If its about to stall pull the line from the water and hold the revs till it clears.

On my old MK2 carb, I was rewarded with a huge sooty stain on my driveway
The engine had been running very rich for a long time before I bought it due to faulty choke components.