Greetings,

1972 914 runs great when cold. Idles good, goes good.

Once it's hot (especially if it's a hot day), have to keep the foot on the gas pedal at stops or the idle drops to zero.

Then I have to flutter the gas pedal to get it back up. Have to hold it at around 2000 to keep it happy. Runs sickly until it get over about 2000 rpm, then run fine again ... until the next stop.

I can generally prevent this by keeping the idle at around 1200 or so, but that is just so I can get around.

Also, when hot, turn car off, turn car on, no cranking.

Fuel system is clean, tank has been drained and cleaned.

Brain has been replaced and tests good. ( Made a big difference, too! )

MPS has been replaced.

I've been having trouble with the fuel pump relay on the control board as well. Thinking about reaming out the contact points with a dremel tool and using dielectric grease. The relays are fine. When I have trouble, I swap the FP relay with any other and it's fine for the rest of that day.

Ground straps from battery and transmission have been removed. Straps and connection points cleaned and shined, and dielectric grease used during reassembly.

I will try setting the idle mixture knob on the ECU up a couple clicks to see if that helps the idle problem or not.

I hate having to go somewhere and wonder if I will be stuck there waiting for the car to cool off so it will start/run.

With the idle problem (which make the car flutter at low rpms .. e.g. have to really flutter the gas pedal to get it going), it's tough to push start.

I understand that these two problems, although related by heat, may not be related to each other in any other way.

I read a thread about the starter problem may be solved by replacing the ignition switch (a second switch would verify this), or by using an old Ford solenoid. Already did the ground strap cleaning bit. Any thoughts?

Any and all assistance greatly appreciated. I never would have thought that a car with less than 80 horsepower would be so much fun!

Thanks,

Lonny

first, welcome to the club!

1 - starter not cranking when hot.
your starter is on it's way out the door. there are some "band-aid" fixes to keep it going for a little while, but it will die eventually.
easiest solution, get a new starter! if you have the $$$, buy a high-torque starter and don't look back ...

2 - relays on the relay board.
first, make sure all the contacts (holes) on the relay board are clean. (disconnect battery while cleaning!)
second, make sure the relay board itself is OK, look at the underside for cracked tar and exposed/lose contacts.
lastly, if the relays don't fit snug, you can (carefully) pry the pins open just a little bit, that sometimes does the trick ...

3 - no idle when warm.
that's a tough one as there are quite a few different things that can cause this.
a few to check:

fuel pressure, add a gauge and see what the pressure is doing at cold and hot
CHT, i forget the exact ohms, but it's been posted here numerous times


question, how high is your idle when cold?
Andy

You should test the CHT Cylinder Head Temp sensor with an ohm meter when the engine is having problems and see what value it gives, it should be less than 100 ohms. If it's too high you have your culprit, and these things can also have intermittent problems.

On your relay board issue, there may be cold solder joints that act up when it gets hot and replacing the relay just gets back contact, if you have access to o known good one try and swap it. Cleaning your actual one is not a bad idea and don't forget that there is the fuse for the pump on the board also and that should be cleaned too along with a new fuse.

Oh yes and read through this if you haven't yet.

Regarding the idle and sickly running at low rpm...
How long since a good tune up? Mine had the same hot idle problem and a new set of points with proper gap adjustment took care of it. Also brought the low-end power band back! If it hasn't had a tune up in a long time, I would suggest doing that before getting too deep into other stuff. It's important to check/adjust the valves as well. Maybe you already have, but just in case you haven't, do the maintenance stuff it needs anyway first.

Thank you, great to be here!

I've read so much stuff about how to fix the starting when hot problem, it IS confusing. If it wasn't that it starts just fine when cold, I would have replaced the starter already!

No worries about points, it has electronic ignition, and has had a major tune up a short time ago. I have literally just been driving it lately, as it has only been running lately.

I had it in the shop for the major stuff, and getting it roadworthy, and now I need to worry about the fine tuning, like idling and starting! ( Only because my funds are limited! )

I was considering spreading the pins on the relays, and I have had the relay board out and sprayed the snot out of it with NAPA electronic circuit cleaner. It looked okay from the bottom. Nothing exposed or cracked.

The car did sit for a couple of years before I bought it, and then sat for another 5 or 6 years before I could invest any funds into getting it on the road.

I will ream out the plugs on the board, spread the pins ever so slightly, and use dielectric grease. I will just go ahead and replace the starter!

I will test the CHT, and perhaps just replace it in any case.

I will worry about fuel pressure later, as the first time I could not 'go' due to fuel pressure (or lack thereof), was the fuel pump relay.

Thanks for the input, it is SWEET to have a source of information.

And of course, once it is running well, I will want to go for 85 horsepower!

Lonny

welcome to a new local from another local. keep your eyes open for gatherings.

k

QUOTE (ltex @ Aug 5 2005, 08:23 PM)

I've read so much stuff about how to fix the starting when hot problem, it IS confusing. If it wasn't that it starts just fine when cold, I would have replaced the starter already!

yes. there are a few different problems one can have with the starter and there are even more "bandaid" fixes for them ...

when the starter wears out, it'll work OK for a while while cold but will hang and not move at all when warm because the worn contacts on the "anchor" can come to rest in a position (while the whole thing is hot and *expanded*) where it doesn't make contact with the counterpart ...
forgive me that i don't know the correct english names for the parts involved ...

this is easily cured by a new, rebuild or high torque starter ...
Andy

Maybe another possibility is, an intake leak. Do you have access to a C.O. machine to see how rich or lean you are running and what your hydro-carbons are reading? That might give you a hint into what is going on. It might be something as simple as the seals on the oil cap or the seal on the oil filler neck housing to the engine case, are broken or missing. Good luck!

Thank you for the additional input. I'm just used to a starter going out. It goes out, it's DONE. This 'cranks when cold, but not when hot' stuff is what threw me.

And the .. uhm .. myriad ways suggested for correcting this in other threads is enough to make one want to just park on a hill all the time.

Moving on .. I'm getting ready to go out and test the CHT, ( heat sensor II ), and clean the positive contacts from battery to starter. I'll check the seals on the caps, and wouldn't be shocked it they're deceased.

The seal on the gas cap is .. present, but dried out and worthless. Smells like gas in the cabin whenever it's filled up or a sharp turn is made. Got some neoprene to make another for it, and may have to do the same for the oil cap.

Personal stuff :

rhodyguy, I've got a bud in Tacoma that's a BMW 2002 nut ..
I'm in Auburn, so we are quite local!

SirAndy, I'm originally from Castro Valley .. ( Or is it Kastro Valley now? )

Thanks again,

Lonny

Okay, I will just go ahead and replace the starter.

As for the idle problem .. AAARRRGGGHHH!!!

The CHT sensor appears to be doing it's job. When nice and
hot it tests out at 60 ohms.

Would it be a fuel delivery problem if it ran good at higher rpms? When it gets ditzy and drops the idle to zero, fluttering the gas pedal gets the revs back, and it runs super at 1200 and above (or so), then will drop back to a normal idle for .. anywhere from 1 second to a few moments, then drop to zero again.

I guess I need to get a pressure guage and check the fuel pressure at idle .. but does that make any sense??

Thank you again,

Lonny