tarheel

waited 5 months for the guy to finish on the body and new paint. I went to get the car and it will not run. Here are the issues. Please help a brother out.

it's a 1986 LG4 with rebuild factory carb with only a few hundred miles since rebuild. Everything else is stock. Car ran great when i left it in Oct.

- hard to start...once started it pops and backfires back through carb. If i can get the car moving it has no power and continues to hesitate and backfire through carb and sometimes through the exhaust.

- checked the distributer cap and it was loose enough to turn by hand. I turned it and it seems to get better and then worse. No idea how far off it is.

- i cannot set timing because the mark is no longer there. I see the indention on the balancer, but the number mark i cannot locate with flashlight.

- fuel is old...i mixed some new fuel in, but there is still some old fuel in there.

- Car has all new filters

Does this sound like a timing issue? It ran great when i dropped it off. He only idled it once a week or so.

five7kid

iTrader: (14)

The timing tab is at 12 o'clock, behind the water pump.

tarheel

i've looked and cannot find the thing. I followed a Chilton's manual as well, but for the life of me i cannot find it.

csmith3

OK, nothing to panic about. In my experiences with no timing tab, I pull the no. 1 plug and locate top dead center (tdc). Then pull the distro cap, leaving all the plug wires on it. Locate the no. 1 plug tower on the cap, line it up with the "finger" (brass tab) on the rotor button. To do this you kinda have to have the cap sitting on the distro, make sure the distro bolt is snug but it still moves with some effort, and then lift a little and peek under there until you get it lined up. After that I always advance it about 2-3 degrees. I just think the LG4 likes about 2-3 degrees initial advance.

tarheel

ok...i'm new at this...but what do you mean here? I pull the plug wire, but how do i locate tdc?

think i can follow the rest of it...i also have a L69 ECM installed which i believe will advance the timing so i'm guessing i should try to find 0 degrees and leave it.

csmith3

What I mean is to take out the no. 1 spark plug, then you should be able to turn the engine by hand. But since you are new at this it may prove somewhat challenging. There will be compression on the remaining seven cylinders so it will be a bit difficult to turn. But to find tdc put you thumb over the plug hole while the eninge is being turned and when you can feel pressure the cylinder is on its power stroke. Keep turning until there is no more presure. Then you can stick a screw driver in the hole to feel the top of the piston. Make sure the screw driver is big enough so the handle won't fit through the plug hole! (just in case it slips) You can then turn the engine back and forth a little and find just about where the piston is at tdc. It might not be 1000% but it will be close enough. I dont want you get in over your head, but to make rotating the engine easier you could pull all the spark plugs, just be careful to mark which plug wires go to which cylinders. If you have a socket and a breaker bar you can use that on the crank pully to turn the engine. If this sounds like some thing you are not ready to tackle I understand, I'm just provinding you with info on how I have done this in the past. So what's up with the paint guy and your car not running correctly after you went to pick it up?

tarheel

lol...yeah, that is above my skill level.

no sure on the paint guy. I delivered the car with no headlights/etc. and one seat. don't believe he went joy riding, but you never know.

I suspect the distributer was loose and when it was idling it started to vibrate and moved off timing. I sure hope that is the only problem.

really sucks though...the car ran great and looked old...now, it looks great and runs old.

csmith3

Too bad. if I were closer I'd give you a hand. But...
Unless you know an honest mechanic, I don't know how else I can offer assistance, I just hate to see people get robbed by "the garage". The only thing is, it can be a bit dangerous with your hands and fingers in the engine bay while someone cranks on the starter to move the engine. I would still like to know how you make out on this though. I'll check back later.

trumps2000

iTrader: (2)

You can't get the timing right until you get a timing mark. If you can't buy one now, I would set the timing to give you the highest idle. I would let it warm up for ten minutes before judging how its running. My car gives me fits after letting it sit for the winter.

tarheel

i played with the z today.....it's a bit difficult to start, but it still idles hard and and after a 19-15 seconds it starts to backfire....and...whenever i try to move the car it boggs down and shuts off..more like it chokes out. The choke light comes on if that helps.

i just cannot move it

any suggestions?

scooter500

iTrader: (1)

to see the timing mark, connect your light, then get a friend to start the car in park and somehow keep it going. hold the trigger and aim your timing light straight down (12 o'clock) aimed behind the water pump, then to look at where the light is shinning you lean over the passanger fender and look through the alternator bracket. It takes a second or two but then you'll see the mark on the balancer spin and timing tab. move the distributor a little bit counter clockwise. the mark should be closer to the end of the timing tab closest to you (a little before top dead center). use an off-set wrench to tighten the distributor bolt.

I had the same missing tab awhile back until I discovered it too. The more I learn the more have to learn

Whatever, these are forgiving engines and nice to learn on.

tarheel

I hear ya...but, i swear i can't find the timing mark...is it embedded or welded on? i ask because i'm looking and i cannot find the mark...period.

i realize these are 20+ year old cars..but i put a flashlight down there and cannot find the mark. I see the indention on the balancer, but nothing to match it with...if it's deep and covered with rust then i maybe i need to clean,but i cannot find the numbers to sych.
i'm lost at this point..i have a bada$$ lookin Z, but can't move it more than a foot. Ahhh this is making me mad.....

trumps2000

iTrader: (2)

See if you can get your hand down there to feel around.

blg0720

I could be off-base here, but when mine was backfiring into the carb, it was a vacuum leak. Fixed that, then the car didn't have much power in the low end. Then the carb was too rich so I tuned it way back and it's fine now.

Just a thought...I'm a dime-store mechanic for a few more months.

tarheel

wow....well i kept looking and moved the small emission hub which all the small emission hoses connect.....looked down and there it was. Has 3 or 4 sharp teeth.

now i have the marks...how to i get the car to keep running while i use the timing light?

da.slyboy

iTrader: (1)

I know this hasn't been asked because it doesn't seem likely someone messed with it, but have you checked for crossed plugs wires?

Grab a friend to keep starting the car for you while you focus on adjusting the timing. It sounds like it stays running for a few seconds before it dies which should give you enough time to peak at where the timing mark is. Add a little bit of chalk to the timing marks to help spot it's location.

Street Lethal

iTrader: (16)

Don't worry about the timing light just yet, as the engine will run, and continue running if it's close enough. Knowing a little about the engine will help you get a feel for it. On the drivers side, starting with the plug closest to the radiator, the plugs are as follows; 1, 3, 5, 7. On the passenger side, starting from the first plug closest to the radiator, its; 2, 4, 6, 8. The firing order, collectively, is; 1, 8, 4, 3, 6, 5, 7, 2. Pull the first plug from the engine, stick your finger in there, and crank the engine clockwise to find TDC. You will know, as pressure will build, and will force your finger out. When this occurs, look at your balancer, and align the timing marks accordingly. Don't start the car just yet. Pull the distributor cap off, and make sure the rotor is pointing to cylinder number one. Double check your wires, and make sure they are in order. The engine should start right up. If your choke light is on, you might have a sticky choke. Shoot the linkage with some WD-40, and watch the choke flap to make sure it is slightly open upon startup, and gradually opening all the way as the engine gets warmer....

scooter500

iTrader: (1)

Street Lethal posted some great advice there. might first try slightly turning the distributor about 1/2 inch clockwise, maybe the car will start. if not then time to dig in deeper

five7kid

iTrader: (14)

Sticky linkage doesn't make the choke light come on. Fried fuse, wire off the choke thermostat, bad choke thermostat, bad choke heater relay, bad alternator - those things will make the choke light come on.

Since you already know the timing is messed up due to the loose distributor, hook the timing light up to the #1 spark plug wire and set the timing. One hand on the timing light and one hand on the throttle is a pretty common practice, actually. Don't forget to disconnect the flat 4-wire connector to the distributor first.

(Holding that vacuum control out of the way is also part of finding the timing tab, and, of course, setting the timing - it just takes a 3rd hand, which most 3rd gen owners have grown. . . )

tarheel

great advise guys....i gonna try 'em.


yesterday, i tried to time it, but the engine will not stay on from more than 10 secs.

i don't have anyone to help until the weekend so i gave up for now. I installed a new cap and rotor last year. I'll check the plugs and replace plug wires.

The choke light does come on before the engine shuts off. During the 10 secs the engine never sounds good....it shudders and backfires through carb...even had one loud backfire through exhaust.

One other thing...i removed the cat converter and will replace with a new one next week. Not sure if no exhuast from cat back makes any difference.

five7kid

iTrader: (14)

The choke light is probably coming on because the engine isn't running fast enough for the alternator to put out enough voltage.

The exhaust wouldn't affect this as long as it isn't plugged up.

tarheel

ok...so i followed the great advice so far....


i replaced all the plug wires...with limited time, i checked 5 plugs and they all looked fine.


When i started the car....well, it actually started and ran for about 25 secs....sounded like it wanted to go high idle since the engine is cold...good sign i know.

well, it wanted to backfire through the exhaust (not the carb) which i take as a good sign.

I did feel a loose plug wire...so either the wire was loose or one was bad. Either way, i feel i'm getting close.

I'll check all the plugs and try the timing light again.

Feel much better about car...thanks everyone!!!

On a side note...received the car with the new paint less than 7 days now and i've had 3 phone calls asking if i'd sell it. Good feeling!

tarheel

thought i'd share the resolution to my issue. Most posters i've been reading on this topic never bother to repost what they found.

Problem was not the timing itself, but loose carb. hold-down bolts. They were loose and creating a vaccuum leak which caused backfiring through the carb.

five7kid

iTrader: (14)

That'll do it.

Thanks for coming back with the update.