74 1.8L problems (numerous)

[murph]

#1 cuts out, like you turn of the key on the highway and then turn the ignition back on. This leads to a hefty jerk in the entire car

#2 NO idle, if you take your foot of the gas, it kind slows down slower and slower.

#3 Poor reving between 1k and 2k. if the engine falls under 2k I usually have to stomp the accelerator down and up VERY quickly to get it to spool up, otherwise it just dies. almost like it has no hp at all

#4 when trying to get it out of the low rpms, the valve inside of the air flow sensor snaps closed, I can hear it from the cockpit.

5# Backfires, I have stock ignition and a bursch muffler. It is not too bad, only with the foot off the gas.

Well,m what do you think, am I screwed, a sucked valve or something like that or what? Oh yeah it goes swell on the highway. Although it does not have as much power to accelerate as it once did (Rebuilt about 5k miles ago) with new heads

[Dave at Pelican Parts]

Could be a number of things, or could be just one thing with lots of symptoms.

Cut-out problems are almost always electrical in nature. Usually there is a connector that is not fully seated, or a wire that is broken somewhere. The jerk is caused by wires connecting, or by wires disconnecting, momentarily. I had a problem like this in my 2.0 that turned out to be a bad wire from the battery to the relay board--the wire that eventually powered the fuel pump.

#2 could be lots of things. It could be an over-rich mixture, which can have lots of causes. It could (maybe?) be a vaccuum leak somewhere, though I can't see the mechanism that would cause that behavior offhand. It could possibly be your timing.

#3 can have lots of differnt causes, and definitely sounds related to #2.

I personally doubt that you could hear the valve inside the air flow meter closing over the noise of the rest of the engine. I would guess that you have a different problem, possibly related to #2 & #3, that is making that sort of sound.

It is possible that #5 is the source of all of your problems. Open up the air filter box, and remove it from the end of the air flow meter. It's been a while, but I think it is only a few bolts or a hose clamp. Try moving the vane in the meter. See if it sticks anywhere along its travel. If so, that can cause ALL SORTS of problems. The backfires can warp the vane, and that can cause the sticking. The only real solution is replacement of the $$$$ air meter.

If you want to find out if you've sucked a valve, do a valve adjust and then a compression check. The valve adjust will tell you if all the valve stems are in place, and if one of them is not lined up with the rest when the valve is closed, you probably have a dropped seat. The compression check will tell you the general condition of the top end.

Then diagnose the ignition system. Make sure you have good spark, check timing and dwell. A friend had problems 2 and 3 with his 1.8, and it turned out his distributor clamp was not tightened, so the timing got very retarded. Inspect the points for wear and pitting.

When you do your compression check, inspect the plugs for color. You want to see brown, or maybe tan. Clean means the cylinder is totally dead. Whitish deposits mean that cylinder is running too lean. Black and fluffy deposits mean the cylinder is running too rich.

After you've done the compression and ignition checks, start checking the FI. Wiggle all the wires to the resistor pack and the double relay, both of which hang off of the battery tray. Dig out the Haynes book, and start doing the component tests described in the Fuel System chapter.

Good luck!

--DD

[This message has been edited by Dave_Darling (edited 05-28-99).]

[murph]

thanx dave
I checked all of the plugs they are all blackish oil, not real bad or anything, but not that brown shade that I had when it wasa a-ok. Here is the shocker, I worked on my air meter last, opened it to see if there was any wear in the circuit board. And gess what, smoke!! Big time! After I got it fired up I saw a whole lot of smoke coming out, as though I was running diesel fuel. Timing, either other way it is worse, doesn't crank or the usual symptons are worse. I am starting to think more and more qustionably at the head what do you think! And oh yeah by the way one of the plugs had some alluminum grindings on it, just abit. However these heads are brand new and came from that head place out in CA somewhere, Ron Stevens High Performance heads, or something like that. It would be a shame after all of the time my father and I spent on the engine, oh well.

[wjdunn3]

Question? When the engine was rebuilt, did you have the distributor out? If so, are you sure you had the engine set at #1 tdc ON THE FIRING STROKE when you put it back in (or aligned the distributor correctly)? I have seen the things you described (though not on a 914) when the timimg was 180dg out of phase. This particular car was a 70 Chevelle. In this state, it was very low on off the line power and smoked like a chimney; but still ran. Kinda off the wall, but worth checking.

[murph]

well, the car was running swell for a while, and the distributer shaft's slot is offset st that it may go on only one way, it is not the timing. The timing has not changed, and has been changed. What are the symptons of a sucked valve, or a broken spring?

[JP Noonan]

Try to find Tom Wilsons book "how to rebuild aircooled VW engines. It gives you specific tests and symtoms, and what they indicate.

I don't have much experience with the 914 L-Jet, but here's some basic stuff.
When you check the timing does it increase and decrease with the RPM, if not the advance weights may be stuck all the way out.
Next, the dizzy can only mate with the drive one way but the body can rotate in relation to the drive. Meaning that you should check that the rotor is pointing at the little hash mark in the dizzy with #1 at TDC.
Check that the spark is big and fat, if it is weak then look at the condecsor and the coil.
See that a wire was not pinched somewhere when you reinstalled the heads. It may have run fine for awhile but then the wire became chafted and you have the problem. I managed to get a CHT wire between the head and the intake tube once, couldn't figure out why the intake didn't sit right. Oh well, working in a driveway, in the dark, isn't the best idea.
The black stuff on the plugs, is it dry and like charcoal (rich) or wet and smell like gas (really rich, late/early timing, dead plug) or is it oily, smears on your hand like the crap on the bottom of the case (oil reaching the combustion chamber either throught the guides, or the piston rings).

What happened in the compression test, what were the numbers? You may have a broken ring.
Or it may be the vane meter. It sounds like you did the test Dave talked about with the key on and just dumped a bunch of gas into the motor. Try it with the key off, what you are doing is checking how smoothly the flap moves, one good backfire can ruin it.

[Dave at Pelican Parts]

For the most part, the sucked valve and broken valve spring will be GLARINGLY obvious when you do a valve adjust.

There are circumstances where it won't be obvious just by looking at the valve stems at TDC, but they are less common. A compression test will still tell you--it'll at least tell you that SOMETHING is wrong.

I'd still suggest making sure the spark is good. Points, dwell, fat white spark, etc.

If those check out, the plug color says that you either have oil getting into the combustion chamber, or WAY too much gas getting in.

Some small bits of metal on the plug MAY be OK just after a rebuild. It does take a bit of time for all the pieces to wear in together. It would take someone with a more experienced eye than I have (a pro or someone who's been rebuilding stuff for years) to tell if what you found is OK or not.

I'd suggest checking the valves (pop off the valve covers and look, at the very least), then doing the compression check. Then make sure the spark is good and all the components are up to snuff, and then start fuel system diagnostics.

--DD

[murph]

Hello again, I finally resolved the problems I have been having!
The majority of the problems have been coming from the points, the one thing that I have beenn doubting. As it turns out, the dwell was way out of wack due to the points not beeing in the hole in which they pivot off of. Of course have one wire to the coil beeing loose didn't help, and also having the head temp sensor's wire was no help at all!
Now all I have to do is get rid of the oil leak I made when I adjusted my vslves.

Thanks to all of those that helped me! Is this BBS cool or what?

=>Mike Murphy

[NINE14NUT]

I used to have a 75 1.8. I had a hard time trying to get it running smooth. I found out the condition of the points on this particular engine are more critical than on D-jet systems because the points also control the injectors. I found replacing the points with a compufire system, really cut down on routine ignition adjustments.