Quick Ignition Timing Question
 

Hey,

If my ingnition timing is off and mis-adjusted, will that cause starting problems? (I apologize in advanve if that's a stupid question)

My car will start, but it takes a lot of cranking. (New cap, rotor, plugs, two new batteries and set the points & gap) I have tested for spark. (seems ok) When key is turned on, I can hear the fuel pump and CDI making noise.

Thanks
Gavin

If it's too far advanced the engine will be harder to crank and harder too start. If it's that far advanced it's not a good idea to drive the car as the extra advance added by the mechanical advance will put you in detonation territory under load.

Christian,

As part of the diagnosis, while driving the car it cuts out around 3,500 to 4,000 rpm. Considering that and the "hard starting" symptoms, does that sound like the ignition is to car advanced?

Thanks,
Gavin

fuel
 

ANd once it starts does it continue to run?
If so it most likely timing, or no compression due to poorly adjusted valves. It sounds like you did a tuneup. DId you adjust the valves?
It sounds like you could use a primer in tune-ups. They sell a really good DVD on PEL.

Zumwoll,

Yes. Once it does start, it will continue to run. So in summary, it is hard to start (lots of cranking) Once it starts, it stays running. While driving, it cuts out a little around 3,500-4,000 RPM. So, that sounds like the timing is off?

I had a valve job done by a shop about a 16 months and 3,000 miles ago.

Thanks,
Gavin

Does it back fire when trying to start it? The mid rpm stumble sounds more like a fuel problem to me, or the timing is retarded too far rather than advanced. Slap on a timing light a check it out. If it's really advanced it could breakup around 3500-4000 but usually they just detonate at that point. Do not drive the car if it's detonating! Check the timing ASAP! I've blown up more than one expensive drag racing engine pushing the limits of timing, even the best parts will fail if detonation is strong enough.

I had my car on the dyno over the weekend, I thought it was too rich but found out it was WAY too lean, so lean it stumbled a lot. 15:1 AF is bad when thrashing a car on a dyno, we shut it off before reaching full rpm. I checked my timing and it wasn't as high as it should be, probably saved me an engine rebuild.

retarded led to a lean mix?

Ron,

no but if the timing is retarded enough it will run poorly above 3000 rpm and yes even stumble.

As for my car and the problems I had, I just recently put an A/F gauge in the car and it wasn't hooked up before the dyno run. When I first put the Zenith's on the 3.0 I only had one set of jets and didn't want to drill them too big. I went with suggested starting size and it ran pretty good. Now it appears I've left a lot on the table as a carbed 3.0 with backdated exhaust and a freeflow muffler should do better than a stock 3.0. I just rebuilt the carbs and it seemed on the rich side at idle turns out idle was jsut right with the idle jets I had in there. The mains are still lean but I have two sets now so I'm gonna drill both sets and go back to the dyno this weekend.

Anyway if Gavin's car is so lean or advanced that it stumbles at 3500+ rpm that will lean to serious detonation and should be fixed right away. The easiest thing to check is the timing, then look at fuel.

Gavin you didn't mention which engine your car has.

My 60 idles are rich at 2 turns but contribute noticeably nice right up to around 3.8k then I guess i'm full on the mains as I see a distinct egt difference from, lets say, 3.5k and 4k+ in 5th. EGT drops about 50F on 135 mains so I figure I'm big time safe for now. CHT increases about 25F. I probably could do 130 mains if gas millage was an issue? This is with 34 vents as they were delivered with 140 mains, 55 idles, and 36 vents.

E tubes either lean or richen the mix from idles to and on full mains. It's another ingredient to consider in the tuning

I think that detonation quickly leads to pre ignition hot spots?

I like this info SmileWavy



http://forums.pelicanparts.com/uploa...1150693285.jpg

Gavin,
What is the point gap? Where is the initial timing?

Yeah Gavin.. set up a signature.

I had the same symptom a couple of years ago...turned out to be the fuel pressure accumulator.

Hey Fellas,

Thanks for your input. Sorry I didn't get back to you on this. (work was a *****) Anyway, A few things:

Car is a stock 71' 2.2E MFI
Mixture is good. (Idle at 4.5 / Load at 9%)
Cleaned the idle air adjustment screws & passages
Gap is set to .016
I lubed the distributor cam / rub block and lubed inside distributor shaft. (pulled the felt plug)
New cap & rotor
New NKG Plugs
Two new batteries

Valves were adjusted about 16 months / 2000 miles ago

The issues are:
Hard starting (Car will eventually start, but it take a lot of cranking)
Once started and warmed up, the idle settles at 1000 RPM but isn't a very "happy" idle. (kinda bouncy and pulses)
Around 3,500 to 4,000 RPM it dies off. (Almost like it has a rev-limiter)

The only thing I haven't done is set the timing. The points were old and pitted so I changed them out when I replaced the plugs. Even though I did not remove the distributor, it seems that I changed the timing when I changed the points and set the gap. (Again, I'm new to this)

Gavin

Check the timing. Also double check the points. My old 2.0E, the points would get out of whack from time to time and the engine wouldn't rev out.

Gavin,
The distributor gap should be 0.012". Reset the gap.
Then get a multi-meter.
Set it to ohms and then set the motor to 5 degrees before top dead center.
So where is 5 degrees BTDC? It's about 5/16" to the right of the Z1 mark.
Turn the motor clockwise and stop at 5 degrees BTDC.
Now connect the meter leads to ground and the connector tab on the distributor.
Rotate the distributor CCW until the points close. You will read continuity, (a closed circuit to ground). Zero or near zero ohms.
Then slowly turn the distributor CW until the points just open, the meter will swing to high or infinite ohms. No continuity.
Lock down the distributor. You have just set the initial timing.
If nothing else is screwed up the motor will run fine.

Doug,

Thanks. That's great info. Today I've got the day off and am going to get this straightened out. I'll report back and let you fellas know. Thanks again.

Gavin

I always install new points a couple of thousands over as new points usually wear in quickly if you don't grease them. If you grease them it could take a 1,000mi to settle in. A quick timing check is easier for me to deal with than playing with a feeler gauge as point wear will affect timing numbers.

point gap of text .35mm = .0137 in

I installed pertronix and keep the points as a back up in the trunk.

Gavin, I just noticed you are from New Jersey too. Did this problem with your car begin just recently? I'm wondering about the fuel we have been buying lately. My car is not the happy camper it was 2 or 3 tank fulls ago.

Hey Fellas,

Well I've got some news:

1. Point gap was off. I had it set at .016 or maybe a hair wider. I reset to .012. Car fired right up and drove perfect. So, that problem is solved.

2. I brought the car to Autohouse (Gene Kirschner) this afternoon to instal new rear bilsteins and adjust the front and rear ride height. While we were there, we put a timing light on the car and found out the initial timing was already advanced to 30 degrees. When we brought up the RPM to 6000, it stayed at 30 degrees.

Gene took it for a ride and thought it had plenty of power and that maybe the springs are worn out or stuck inside the distributor causing the initial timing to stay at 30 degrees advanced. He thought that since the car was running so well now, and that the timing was correct at 6,000 RPM than we should leave it.

Any thoughts?

Mystery Train - I'm not sure about the gas quality. Mycar had been running so rough lately it is tough for me to say.

Gavin,
Absolutely not. The car will continue to be hard to start. It will run hotter than it should. 30 degrees ignition advance is only correct for a motor running at 3,000 plus rpm.
This is not good for your car and needs to be fixed. It could be as simple as a really good cleaning and relube of the distributor. You may need to replace the distributor with new or a good used one.
I'm confident you can find a fix or replacement on this board.
Check the classified parts section and run a Want to Buy (WTB) post.
I am coming on strong because you really don't want to ignore a stuck distributor, it can cause more grief down the road, a short road.
Good luck,

Edit: There is an ad for parts from a '74 motor located in NJ. May have what you can use. In the classified section.