What's wrong with my engine?

[Pritchard]

Let me first say thanks to Pelican for this BBS. If it were not for this place to get advice, I would have let my 914 go a couple of years ago.

Anyway, to the question at hand. I have a '74 914 2.0 L that is pretty much stock. I have a breakerless ignition and what I think to be the 1.8 L dizzy. The heads were recently rebuilt and the valves adjusted. My compression is low, about 115 psi on all four cyl. I am now kicking myself for not replacing the rings when I had the engine out and apart. On that note, how much for a set of rings for all for cyls?

Here's my problem: the car is suddenly almost impossible to start (it will start then die within a second or two). Continuing this start and die process a few times will eventually get the car running enough that I can keep it running by using the throttle. It runs great after warming up (about five minutes).
OK, these symptoms point to the CHT, which is reading only 1100 ohms when cold. How relative is "cold?" It was 90 degrees when I checked it. I assume that this would still be considered cold to the ECU.
So I have ordered a new CHT from PP, of course. Should have it in a couple of days.

The other problem that I have no idea about is, the engine misses (not too bad) at all RPM's. I have installed new plug wires, new plugs, adjusted and rechecked the timing, checked for spark at all plugs, checked for signal at the injectors, adjusted the TPS, and probably a couple of other things that I can't remember right now. If you have any thoughts on this, please let me know.

The fuel filter is due for a change. Could this be a part of the problem?

Thanks
Pritchard

[bowlsby]

Definitely change the fuel filter...if its clogged, its constricting the fuel flow. A new one every 2 years is what I hear.

The missing and hard starting may be improper dwell/timing or valves out of adjustment.

[JP Noonan]

With the D-Jet it isn't possible to use a 1.8L dizzy because the L-jet dizzy (1.8L) dosen't have the FI trigger points in the base of the distributor. The FI points plug into the harness with a three terminal plug.

See if there is a inline resistor between the CHT and the harness, it is about 2" long 1/4" round and black. Remove it and see what happens.

Check the D-Jet article on the 914 fans web site, but I think the CHT is 3000 ohms cold, and <300 ohms hot. I could very well be wrong on those numbers.

Gotta go, I'll check back later. but see if a PO messed with the MPS, and try a good injector cleaner, I doubt the fuel filter would do it unless there is rust in the tank, but even then it wouldn't be temp related.

What did the tips of the plugs look like? All the same, 1 and 4 looked different than 2 and 3???? This is an important one, if you can take a look at the plugs ntoday and get back with us.

[Pritchard]

Thanks guys.

The tips of the plugs are black. Looks like it is running rich. All four look the same. I definately don't have the 1.8 dizzy if it doesn't contain the FI contact points. There is no resistor added in between the CHT and the harness. The PO has indeed adjusted the MPS. There is no "plug" on top of the adjustment screw. I also adjusted the MPS when I put the engine back together. It was starting and running quite well (although it was missing slightly) before these problems raised their ugly heads. The specs on the CHT sensor are'tween 1500 2500 ohms when cold and <300 when hot. My current CHT registers <100 when hot.

Went to lunch after first post, car ran as good as it ever has. Go figure. Tomorrow morning will be a different story though.

Thanks again
Pritchard

[This message has been edited by Pritchard (edited 08-11-2000).]

[Steve Frankiewich]

Can't say about 1.7 or 2.0 distributors, but I had the two vacuum advance hoses on my 1.8 distributer switched and it drove me crazy--no power, missed increasingly worse as RPMs increased. But that isn't apparently your problem.

My other problem sounds similar to yours, however, an intermittent miss that sometimes disappeared, at other times occurred sporatically, and at other times was constant. The sparkplugs were black with carbon. The problem ended up being a short between the two wires in the plug that went to the Temperature sensor mounted under the air runners to the right side head. Age and temperature had hardened both wires' insulation which then cracked at a bend in the wire. This allowed the wires to short, sending a signal to the fuel injection to WAAAY enrichen the mixture. Making the short harder to find was the fact it occurred near the connector inside the rubber boot where the wires go into the connector plug.

I put some electrical tape around the insulation and the car ran like new.

[Pritchard]

Steve-

Are you talking about the temp. sensor for the cold start valve or the CHT?

Thanks for the idea. I haven't even considered an electrical short somewhere.

Pritchard

[Steve Frankiewich]

I believe it's called the thermo-time switch.

[Pritchard]

Well, installed the CHT and car started right up. I was pleased. It idled great for about two minutes then died. Cranked it back up. Idled for about 5 second and died. Cranked it back up. Idled for about 2 seconds and died. Did the same thing a couple more times. Got frustrated and went inside.

Went back to garage and cheked TPS, AAR, compression, signals to injectors, spark plugs, MPS, looked for exposed wires that could be shorting out. Found nothing that was out of the ordinary. Plugs are black with carbon.

Help me please!!

Pritchard

[John Rogers]

What is the fuel pressue when running? Also immediately after starting, pinch off the fuel line to the starting injector with a small clamp. Good luck.