Engine Temperature Questions

[mountainkowboy]

I posted this in the Samba, but didn't get much feedback, so................

When I got to work this morning I checked temperatures on the engine with a point-and-shoot temperature gauge. At the exhaust port its running 370 degrees, in the middle of the head I'm running 275, and the cylinders are running 260. The case is running 175 degrees everywhere even at the oil screen plate. These temps seem to be in the ok range from what I can find. The back story is last week I had a "vapor lock" type issue after running down the highway at 65mph with the top down on the bug and from time to time now I'm getting a similar issue. It acts like it cant get fuel after I pull in somewhere and shut it off for a short amount of time. It will start for a second, then die like its out of fuel, at that point I have to floor the pedal and crank it for 5-10 seconds before it starts. After it starts it runs badly for 10-20 seconds then its fine. Maybe my fuel pump is going south?


Opinions?

[ps2375]

Where does your fuel line run? I have heard that sometimes running a rubber line over it can insulate the hard line from heat and help with vapor lock.

[volksbugly]

since you have the deck lid standoff and the deck lid, I don't think its vapor locking, check your fuel pump rod for binding, also check to make sure you're getting proper fuel pressure fuel pressure is adjusted by the amount of gaskets you use. Use some emery cloth on the fuel pump rod if you suspect it's binding.

[Bruce.m]

I have experienced similar symptoms. The pivot in the fuel pump housing had worn to an oval shape which reduced the pump stroke and therefore it's output. Hot starts were a total pain.

[volksbugly]

Here is a video that talks about it
https://www.youtube.com/watch?v=eU6aVBW71Es

and here is an oldschool video
https://www.youtube.com/watch?v=L-QDI74acLY

[Marc]

Have you established whether the problem is a shortage of fuel or too much (as would be caused by fuel percolating in the floatbowl and spilling into the intake - evidenced by odor or the presence of a black puff when it does start)?
Your car was originally equipped with a pressure relief valve on the discharge side of the pump which would let "boiling" fuel in the line return to the tank side rather than expand and force open the float valve. It didn't do a lot, but the factory wouldn't have bothered with it if they hadn't considered it necessary. They're very hard to find these days since most of them were tossed out during fuel hose replacement by the `80s, but IMO it couldn't hurt to try one if you can get it for cheap.
http://images.thesamba.com/vw/classifie ... 742862.jpg

[mountainkowboy]

Thanks for the info guys, I'm leaning towards the fuel pump and starvation. There is no puff when it restarts and its heat related. It hasn't done it since the "heat wave" has stopped. I also re routed the hard line when I pulled the engine and installed it in the Ghia along with fixing the oil leak (donuts on the cooler). I am carrying a new pump with me for now since the one that's on there looks to be pretty old, I don't think that they even make this pump anymore.

[Marc]

Are both pumps "high-pivot" or "low-pivot"? If not you'll need the other-length pushrod for use with the spare, there's an 8mm difference in length.

[mountainkowboy]

same pivot, its just the new style

[mountainkowboy]

Could a coil cause the issue? Today while messing with it (electrical gremlins) I took it out for a drive and got it good and warm. I didn't have any issues till I went to restart after a short stop, and once it "cleans up" it runs fine. When I got back I opened the rear up to see if I can hear boiling or something, but nothing. However the coil was REALLY hot, I mean cant touch it for very long hot.

[Corysvdub]

That is quite a possibility. I had the same issue on my Squareback, had to let the coil cool off for 30 minutes. Changed to a different coil setup and never had that problem again. Then went fuel injected shortly after.