924Board.org

[badenkb]

Hi All,

You may recall the long thread earlier about the non start problem on my 924 project ?
It has now got to the point where the engine will crank and fire and even run, very poorly for 3-4 seconds at about 100rpm or so, before stalling.
A couple of questions:

Can anyone help me with a brief guide to static timing ?
Should the centre pin of the 7 pin white connector in the engine bay get 12V with the ignition on ?
When the engine is running briefly, it sounds like the timing is way out - backfiring and popping - (hence my earlier question) - what other causes could there be?

Any help is greatly appreciated!!

Many thanks

Ian

77 924 na

[dpw928]

Ian,

It sounds as if you are running on the cold start valve only which would explain why it is backfiring (lean condition) and quitting after a few seconds. Have you adjusted the airfuel mixture on the fuel distributor? The adjuster is in the hole between the fuel distributor and the air horn. It takes a long allen wrench to adjust it but I'm not sure what the size is. Turning it clockwise should richen the mixture. BTW a small adjustment (1/8th turn) should have a large effect on the richness. If adjusting that does not help, the problem is probably still in your fuel distributor or warm up regulator.

Dennis

[-nick]

getting fuel is easy enough to check too. just pull an injector out of the head and see if you're getting a spray while you crank the engine over.

if the dizzy rotor is even pointed close to the right cylinder when cranking you should be able to get it to start. your dizzy timing can be off by a pretty amazing amount and still run.

you might also want to check the cam timing on the timing belt. do all of your notches line up? i made the mistake of lining up the wrong mark on the cam once, there is a dot on one side and a notch on the other. i believe the dot is the mark you want.

how about your plug wires, in the right order? that's it really for ignition problems, assuming you're getting a spark.

hope this helps,
-nick

[wdb]

the backfiring and poping could be due to the extremely low RPM's ,both valves are open at the end of the cycle

[badenkb]

Thanks for the info - I'm unhappy about the timing on the engine - think I'll look there first - though I suspect the fuel distributor is still at the heart of my problems.

Ian

[badenkb]

HI All,

Sorry to be hassling listers again, but I am certain the static timing is OK now - set flywheel to +10 degrees for UK (as per Haynes), camshaft dot to pointer on valve cover and no. 1 cylinder valves both closed and rotor arm in dizzy pointing to No.1 spark plug and aligned with notch on dizzy housing. Spark plugs firing order 1-4-3-2 as per Haynes.
Result ? engine catches briefly and may stumble for a few seconds before failing. Repeated attempts are less and less successful.
When I remove the plugs to check them, they are always covered in oil/fuel and black (even though they are new).
Is it possible that the oil has quite a bit of fuel in it and oil seepage into the cylinder bores is hampering any attempt to fire ? My attempts to change the oil failed when the sump drain plug would not unscrew! Again - is it common for the plug to weld itself in to the aluminium sump???

Help please!!

Ian

[wdb]

I dont know about the 924,but I have seen other cars with a bad O2 sensor do the same thing, start and run for a few seconds,than die

[-nick]

the '77 didn't have an o2 sensor yet. so no dice there. did you check for fuel spray? have you pulled a plug out and cranked the ignition to see if you've got a good spark? the ECU is another common culprit. it may be time to take a peak at its guts to see if any of the solder connections have come loose.

if the fuel distributor is bad you can get extreme flooding which would give you the symptoms you describe. the more you crank it the more the cylinders fill up with fuel. i'm not exactly sure how to check the fuel dist though.

btw- anytime you've put aluminum and steel together they seem to want to weld. you should try removing your exhaust studs!

good luck- keep us posted,
-nick

[badenkb]

Does the 77 have an ECU???
Its not even got transistorized ignition (still contact breakers).

Ian

[-nick]

oh sorry, i forgot some of the really early cars had points! no ecu to check then.

just curious, what's the build date sticker say for yours? my 77.5 has a sticker that's something like 4/76. my early '77 was 2/76 i think. is your listed as '75 maybe?


**my mistake, my 77.5 build date is actually 4/77. i think my early '77 was built in '76 though.

-nick

[ This Message was edited by: -nick on 2002-01-30 05:41 ]

[TonyMechanic]

A common problem when cranking a car for a long time is that it will flood the cylinders with fuel, the fuel will then coat the cylinder walls and seep past the rings and into the oil. This will cause the cylinders to get VERY little compression and will only increase your problem, your solution is to change the oil, pull all of the plugs and clean them off. If you don't have a spark plug cleaner, just spray some brake clean on them, then blow them off and make sure they are dry before you put them back in. Then use vise grips to clamp off a fuel line and crank the engine over for awhile. It sounds like your timing is close, and engines will run, although poorly, with the timing way off, try cranking it over with the fuel line clamped off and spray starting fluid into the intake (directly into the metal intake) if it begins to run like this, unclamp the fuel line, and a second later stop spraying the starter fluid. Let me know how it goes.

[numbers]

Also, since you do have a breaker type distributor, have you checked the point gap. One degree of dwell is equal to three degrees of timing. So, a small gap error can result in a large change in timing.

[numbers]

Let's go back through the basics. The problem has to be either ignition or fuel. You can isolate the ignition by performing the spark test using a screwdriver plugged into the end of a spark plug wire. Spark should jump at least 1/4 inch to ground while cranking. If it is doing that, then the engine should fire unless your timing is way off, or you have a fuel problem. To check for a fuel problem you need to pull an injector with the fuel line connected. Put the injector in a jar and crank. You should have a nice even spray pattern from the injector. Post the results of those tests here and we can go from there based on the results.

[TonyMechanic]

An engine that did run, needs 3 basic things:
1) Proper Fuel
2) Proper Spark
3) Proper Compression
You can always force proper fuel (use Ether) so check for spark (like numbers was saying) and if thats good, maybe a compression test.

[Roger Hall]

Three things that you can check in 30 mins.

Spark at plugs
Fuel spray from injectors
Fuel pump relay

You should probably follow the trouble shooting procedures in the haynes manuale though.