switched to electronic ignition, not smooth

[salty87]

454 engine, was running points but switched to electronic ignition this year. i was having trouble getting spark after letting it sit for a couple of months. rather than a tune-up kit, i made the switch to electronic ignition...pertronix. i also replaced the distributor cap, coil, and plugs (wires are only 1 or 2 seasons old).<br /><br />after messing up the wires and getting that straightened out, it ran great. i set the timing but after a couple of minutes it started running slightly differently. the rpm's would speed up and then it would stumble, repeating. you can see it with the timing light and hear it. same would happen at higher rpm's though not as noticeable. changing the timing further didn't seem to have any effect other than the idle. all of this was on the hose, haven't taken it on the lake yet.<br /><br />also, this never happened before, after stopping the engine with the hose still on...water was coming out of the exhaust pipes. any chance that's related? any idea what causes that?<br /><br />did i not get the timing right or could there be something else going on?<br /><br />thanks

 

[Darkhorse1201]

Re: switched to electronic ignition, not smooth

If the timing changed too much, you might have sucked in some water into the cylinders wich would make it run like crap. JMHO

 

[calwldlif]

Re: switched to electronic ignition, not smooth

"after messing up the wires and getting that straightened out, it ran great"<br /><br />Electronics are sensitive.<br />How old a motor here?<br /><br />It is hard to say, timing mark "floating"<br />around. This is a symptom of stretched timing<br />chain. The new pointless unit cold be "dicey".<br />Heat, poor wire connections, cause some unusual<br />things to happen.<br /><br />The rpm changes point me to fuel, but the <br />floating timing says:<br />Mechanical advance(disrupted by pertonix install)<br />binding, bent, missing spring.<br />Timing chain stretched.<br /> I am guessing here, there something(info)<br />I am not seeing, or missing.

 

[salty87]

Re: switched to electronic ignition, not smooth

thanks for the replies, more info<br /><br />engine is an 87, 800 hours. timing chain was replaced at 500 hours while fixing a seal leak. much sturdier looking chain than the oem.<br /><br />running a basically new carb...edelbrock instead of holley now. it has maybe 100 hours.<br /><br />it's not running that rough, just not as smooth as it should. i could probably take it on the lake but don't want to. the cylinders aren't firing in a smooth order...you can hear 4 or 5 run a little fast, then a slight pause before the rest. then it repeats...a few hits too fast, a pause, a few too fast, pause, etc. changing the timing seemed to change the speed but not the rythm.

 

[calwldlif]

Re: switched to electronic ignition, not smooth

These symptoms point to:<br />Cam<br />Dead/weak cyl<br />Carb<br />Vacuum leak/manifold<br /><br />The timing mark "floating" you discribed<br />Point to other issues.<br /><br />I am afraid there is contradictory type info.<br />Are you sure the advance plate in the dist<br />isn't binding or stuck?<br />Does the wiring to the pertronix allow<br />free, smooth advance?<br /><br />Info overload here/ will mull on it.<br />Hopefully some else will fair better on the <br />info supplied.

 

[cobra 3.0]

Re: switched to electronic ignition, not smooth

Did you put in a pertronix I or II? What kind of coil?

 

[salty87]

Re: switched to electronic ignition, not smooth

it doesn't say 1 or 2 so i assume 1, this is the pckg:<br /><br />

<br /><br />i went with a pertronix flame-thrower 1 coil...both are 1.5 ohm resistance.<br /><br />there's nothing for the wires to bind on. the only thing left under the cap now is the electronics module and rotor. the plastic sleeve prevents the wires from hitting the rotor but it won't hurt for me to take a look.<br /><br />any other thoughts?

 

[bruceb58]

Re: switched to electronic ignition, not smooth

If the timing is moving around, what RPMs is the engine varying between? That might not be a problem if the distributor's mechanical advance is reacting to the engine RPM.<br /><br />How did the engine run before you changed the ignition system? If it ran fine, then you possibly did something wrong on your install.<br /><br />Or...maybe the electronic ignition kit failed...I have heard that before.<br /><br />Even though it is an electronic pickup, you can still measure your dwell. Only difference between points and what you put on is that now you have a transistor simulating the points. Measure the dwell with a dwell meter and see if it looks ok.

 

[newport dave]

Re: switched to electronic ignition, not smooth

salty,<br /><br />If you are using the Flame-Thrower coil, you are supposed to eliminate the ballast resistor/resistor wire to run a full 12 volts at the coil. Did you do that?<br /><br />Dave

 

[salty87]

Re: switched to electronic ignition, not smooth

the engine ran great before switching to electronic though it wouldn't start recently which is what prompted the change to electronic. been meaning to for a while.<br /><br />there isn't much to do on the install, rip out the old, put in the new, run 2 wires. it did have instrux for how to wire it with a ballast resistor which i do have. there's a trouble-shooting tip to run a jumper to bypass the resistor which i tried and still have the same slight surge and stumble. i don't recall seeing any instrux with the coil but i'll look again.<br /><br />i tried to get the idle to about 700 but it speeds up to close to 900 and then stumbles down to about 550 or so. it will stall every couple of minutes but not at every stumble.

 

[whywhyzed]

Re: switched to electronic ignition, not smooth

Originally posted by salty87:<br /> the cylinders aren't firing in a smooth order...

I would quadruple check the firing order....

 

[KaGee]

Re: switched to electronic ignition, not smooth

I would also inspect the distributor advance weights.

 

[salty87]

Re: switched to electronic ignition, not smooth

Originally posted by KaGee:<br /> I would also inspect the distributor advance weights.

anyone have a link where can i read up on that? i don't understand how the advance or weights work and there isn't much left under the dist cap. what is left is rusty. my manual discusses rebuilds more than diagnoses problems.<br /><br />i'm going to check the plug wires again for sure. it doesn't seem to be running as rough as that but i had them jacked up before.<br /><br />thanks again

 

[KaGee]

Re: switched to electronic ignition, not smooth

Underneath the plate where your points used to be are two counter weights that swing out with centrifical force. As they do, they turn the plate slightly advancing the timing. They are connected by springs. What happens normally is that everything corrodes causing the weights not to expand, so your timing advance is retarded.<br /><br />Im thinking in your case that maybe a spring broke or became disconnected while you were swapping things out allowing a weight to fly around freely. Just a wild idea. You need to inspect there anyway seeing how you say it's all rusty.

 

[fendersfender]

Re: switched to electronic ignition, not smooth

I would be leaning towards fouled plugs or plug wires on wrong cylinders....if engine runs smooth at idle, then distributor advance should have no effect.......or it could be faulty pick-up on electronic ignition.

 

[ron7000]

Re: switched to electronic ignition, not smooth

Originally posted by salty87:<br /> the engine ran great before switching to electronic though it wouldn't start recently which is what prompted the change to electronic.<br />

I think what's leading you to believe the cause is the changeover to the pertronix is just coincidence. They are pretty much bulletproof, if the engine starts then you have it installed correctly. You mentioned you let the boat sit a couple months, that being the case I would bet on the carb being the culprit. In addition, you've changed carb to an edelbrock, are you sure it's set up properly? How long have you been running it? Are you sure it's installed right and there's no vacuum leak anywhere or one did not develop? Timing chain was replaced 300 hours ago, I'm assuming engine ran fine since if so then you can rule that out. Like was said, check your wires and firing order, have someone else do it even to verify. It's easy to have tunnel vision and look at #5 going to #6 cyl and see nothing wrong. Check your wires too, I've f'd new ones up trying to get them on/off so there's a chance there's that. Quite a few variables to rule out, but I would still bet on the carb.<br /><br />I don't know the condition of your distributor but a worn out one with slop in the shaft can cause these kind of symptoms, and an electronic ignition conversion won't fix that. The effects of a bad distributor are usually at higher rpm and less at low rpm, but there's a chance so check everything.<br />here's a link that may help, I'm guessing you have a mallory. if you can post your distributor number that would help.<br />Any water condensation under the distributor cap?<br /><br /> http://www.centuryperformance.com/mallory/assm.asp

 

[calwldlif]

Re: switched to electronic ignition, not smooth

"i don't understand how the advance or weights work and there isn't much left under the dist cap. what is left is Rusty ."<br /><br />There should be no rust in the dist.<br />Surface discoloration OK, Chunky stuff NO<br />I don't have a picture of the advance mech.<br />Basically the plate you mount points to can<br />turn/twist, pivoting on a plate under it.<br />This turning/twisting changes the point were the points open. It is like when you twist the dist to set the timing. How much it turns/twists<br />is controlled by weights and springs. The weights<br />want to move outward (centrifical force)and twist/turn the plate that holds the points. In an<br />advancing direction.(like turning dist to increase the timing advance.)<br />The springs are there to keep the weights from<br />moving "outward" so the advance dosn't happen(no twisting/turning). as the speed of the rotor/dist shaft increases the centrifical force increases<br />forcing the weights to overcome the springs<br />ability to hold them from twisting the point plate in an advancing direction. WHEEW<br /><br />Now this point at which the weights overcome the springs(allow plate to turn)is measurable<br />and specific.<br />Lets say your basic timing setting is 10 deg adv.<br />this at 600 rpms. At 800rpm the weights overcome<br />the springs and now the timing is 12 deg adv.<br />1500 rpms and now 16 deg adv and so on till<br />max of 35 deg advance. at probably 3000rpm.<br />I made these numbers up because I don't know what the specs are for your motor. There is a table<br />that will tell you what adv should be at a specific rpm. It usually tells you at what rpm<br />the adv starts(weights first overcome springs)and <br />how much should be at a specific rpm.<br />EX 900 1 more deg 1200 3 deg more 2000 6 deg more ect.<br />What happens when rust get in the works it causes sticking of the plates twisting/turning action.<br />so you advance sticks jumps moves in an eratic<br />fashion. Find your motors specs and test it with a tach and timing light. <br />The timing mark lit by the timing light should not move back and forth, it should stay steady<br />at a given rpm. I hope that makes sense.<br /><br /><br />"the engine ran great before switching to electronic though it wouldn't start recently which is what prompted the change to electronic. been meaning to for a while."<br /><br />I am too tired to address that now.<br /><br />" i tried to get the idle to about 700 but it speeds up to close to 900 and then stumbles down to about 550 or so. it will stall every couple of minutes but not at every stumble"<br /><br />I am too tired to address that now.<br /><br />"it's not running that rough, just not as smooth as it should. i could probably take it on the lake but don't want to. the cylinders aren't firing in a smooth order... you can hear 4 or 5 run a little fast, then a slight pause before the rest. then it repeats...a few hits too fast, a pause, a few too fast, pause, etc. changing the timing seemed to change the speed but not the rythm."<br /><br />I am too tired to address that now.

 

[calwldlif]

Re: switched to electronic ignition, not smooth

Well,<br />Sometimes when 1 aspect of a motor is <br />improved, other aspects show their weakness.<br />The 4 5 good cyl hits, then misses means 1<br />thing, 1 or more cyls aren't firing well.<br />Possible bad wires, crossed wires, fouled<br />plugs. Possible carb if the weak cyls are<br />sharing the same side of the carb.<br />I don't understand when you wrote<br />"won't start so I changed to pertronix."<br />It is hard for me to sit here and definately<br />tell you where to look.<br />If you dist upgrade is sound and the advance<br />is free and smooth, and wires are correct,<br />then find the weak cylinders. Pull 1 wire<br />off the spark plugs and note any rpm changes.<br />A wire that doesn't drop the rpms or the drop<br />is slight then it is not working properly.<br />If you find weak/dead cyls check wires, plugs<br />and if need be compression check. If the cyls<br />that are weak share a common side of the carb,<br />check that.<br />Motor is a big pump, if you have compression<br />fuel, spark, it works.<br />Good luck<br />let us know what you find.

 

[salty87]

Re: switched to electronic ignition, not smooth

thanks for all the replies and explanations, i'll be able to spend some time on it this weekend and will reply with the results.<br /><br />since it was running good previously, i'm going to check:<br /><br />plug wires<br />compression<br />advance and rotor assemblies<br /><br />thanks!

 

[northvanwatertaxi]

Re: switched to electronic ignition, not smooth

i'm thinking that you can also check t.d.c and make sure that the timing mark lines up #1 cyl. use your finger, you can rotate the motor (clockwise) with a socket wrench when it gets to tdc it will pop off<br />i have pertronix too because i have to...belive me you want points, they are cheap and if you blow your pertonix it will cost over 100 bucks