My engine seems to be running too hot. All 4 plugs (WR7CC) look super clean like new still, backside of exhaust valves are kind of white colored and engine keeps running a few turns when I turn off the ignition. But it idles great, has oil pressure and seems to drive really good too (only taken it around the neighborhood a few times and I have nothing to compare it too). It's a 72 1.7 with the stock fuel injection, and solid state ignition SI-4000F, stock igntion coil..

It was sitting for 12-13 years, not sure if that has anything to do with it? It was in a VW/Porsche shop in 1996 (Aker's in SEattle), and they put W8CC plugs in it which someone told me are colder than W7CC right? Those plugs looked a little better when I first got it, some black around the edges but the tip still looked a little too clean to me. Could one of the fuel injection components have gone bad from sitting and motor still runs good? What all should I check out? Should I go back to the W8CC plugs? thanks

If it's been sitting, run some good fuel injector cleaner through it. Check fuel pressure (the pumps go bad sometimes if left dry).

It has been running fuel injector cleaner, I dumped one of those little bottles in the last fillup.. 2 of the injectors are new and since the plugs look the same on all 4 I think the injectors are fine. I checked out the fuel pressure today and it was around 30psi which looks close enough to what the book says.

Once I get my new heat exchangers on, I'll try out this exhaust gas analyzer I have lying around.. maybe it'll show what throttle range is running lean. It's a Heathkit thing with a sniffer tube.. anyone try one of them before?

When I did my first tune up I wasn't sure where to set the mixture knob so I went old school and looked at my exhaust pipe which was quite black and sooty so I leaned the mixture 1 click and drove for a while and kept doing that until the exhaust was light brown, engine was running great, and yes I was very mindful to not run it too lean as that is when serious damage can occur due to running hot so I never let it get hot. Finally got hold of an exhaust analyzer, the Heathkit one, which works great by the way, and my mixture was bang on.

Ian Stott
Moncton
Canada

......if you know what your doing the "old school" techniques work....YOU might just check the ignition timing. It could be advanced just a little too much."it keeps running a little when I shut it off"....ignition timing is too advanced, if you really drive it around and get it hot it will "knock"..Thats also called detonation...(if you can hear it over the exhaust). you should use the highest octane gas at the pump.The injector cleaner will lower, your octane........

It sounds like its running lean.... BTDT

btw, HOW hot is it running? you never mention the temp you have seen...

The mixture knob on the ECU is only - ONLY - for adjusting the idle mixture. It has no effect on your mixture under part or full load.

Did you check your mixture while under load? I have a Heathkit meter, too. You can use a clip to hold the sniffer tube in the exhaust, and put the sensor part in the trunk while driving. You have to prop the rear deck lid open with a shop cloth. Get the car fully warmed up and get on a flat, straight road, where you can drive at about 35 to 40 mph at around 2500 rpm. Your mixture under those conditions should be at least 2.5% CO. Anything below that is too lean.

From what I can tell, you are assuming you are running hot... Spend $100 and get a good CHT that will measure youir cylinder 3 head temp.

Check your timing and adjust your lifters.

Eric Read

I agree with Eric, don't make assumptions, make measurements! And when you have a car that's sat for a long time, do a complete checkout of the fuel supply (volume, pressure, injector spray patterns), ignition (you know the drill), and FI components (see my page).

You were right, the timing was advanced.. I assumed looking at the previous owner's $3k shop bill they would have at least checked the timing.. It's not supposed to change with electronic ignition is it? The plugs are looking more normal now, getting good readings on the gas sniffer and no more dieseling

Yes, timing can change with electronics, so can dwell. Can't really set the dwell with the electronics, but you will see a difference in timing. Just did a new one on mine last week.

I've got one. Works great, lasts long time. It's slow to react though. It's not a wideband digital.

.Terrific...jeremiah 08125.....As a point of intrest do you recall how much it was advanced too far..? total timing advanced to cause the run-on -detonation?...AND THANKS.... for informing the 914,ers on the solution....More/everyone should relate the solutions to their problems. It builds a body of knowledge for everyone....thanks again..............M.M.