I tried starting the car yesterday and It was running like crap and it really didnt want to run at all if I didnt give it gas. Everything is new on it from top to bottom so what should I look for if the #2 and #7 cylinder arent firing ??

 

spark is not there or the engine will not fire on those two cylinders? what exactly are you saying? if the spark is there i would look for valves adjusted to tight keeping compression at zero.

 

What he said. And make sure you didn't swap the number 2 & 7 plug wires. They're right next to each other on the dist.

 

Well the first thing I thought of was no spark did think of valves. The car ran like crap so I went to the motor and noticed that both the #2 and #7 header primary were cold and the rest are pretty hot. And when I broke the motor in last october it ran fine and I haven't driven the car yet the motor has 0 mile on it and has just been sitting there.

 

Check the wires for continuity with an Ohm Meter - I've bought brand new high dollar wires that were broken. Also check to make sure the plug boots are all the way on the plugs - I had one that would pop off on it's own - I crimped it slightly with pliers to get it to stay on the plug.

 

i had similar problems, rocker arms weren't adjusted properly, did you adjust them yet?

 

I will check the plug wires and I havent done anything with the rocker arms.

 

good, let us now what happens

 

Did the motor sit for a wile after it was built?

 

The motor sat for about 3 months and then I broke in the cam. Then I started now in then but never driven due to the tranny but the motor ran fine last year. Now all of a sudden it runs like crap this year.

 

i bet your lifters bled down

 

WTF? I really dont think that is his problem at all. No clinky clinky, and besides the engine is running, it has an oil pump. More than likely its either an ignition issue, or the valves not adjusted properly. The problems I see are as follows: if the plug wires were backwards the primaries would still get hot and the engine would be firing in the wrong sequence i.e. flames out intake probably. The problem with the valves is basically the same, you would still have fire in the holes. I almost wonder if there isnt any issue in the dist. cap or distributor area here. pull the plugs on those holes and crank it, see if there is spark. Then compression test, thats the for sure way to see whats up.

 

Okay thats fine and dandy, he still has spark on those two cylinders except if the firing order is off, they're not gonna fire at th right time, they probably won't burn any fuel that is even in the cylinder, and even if it does it probably will blow through the intake like you said, but not through the exhaust, therefore the header is still cold,

if the valves are out of adjustment it could be in two ways, either the lash could be too tight or two loose, if its to tight fuel will leak back by the valves on the compression stroke, and even though some fuel will burn, the cylinder will be generally cold if the valves are two loose the amount of fuel in the cylinder will be greatly decreased, but the exhaust may still be hot on that cylinder, power however will be comprimised,

now this is just the conclusions ive came to after i had these problems with my car

 

yeah either the rockers being to loose or too tight he would still have compression and a A/F mixture to burn... so they would still get hot
and he hasnt said anything about backfires so i am betting the cam timing is okay

this is going to be a spark problem

 

no if he has spark there will in fact be combustion in those cylinders, it will occur at the wrong time however. There will definately be a noticable difference in the sound as in backfiring through intake etc. The unburned fuel charge will still be lingering when the spark hits. If the valves were too loose there would be rattling clacking, as in when I said there was no clicky clicky (remember?). If the valves where too tight, a compression test, like I said above would help to point his out.

 

I had no compression in my engine when i had the rocker arms to tight, also where did he say the motor wasn't clacking, i don't see it anywhere in this thread lj?

 

YOU ARE PROVING MY POINT!!! READ ABOVE!!!! I said in my original post, which you disagreed with, that if there is spark, check compression. DUH! If you are just wanting to argue, lets go over to the street racing board. It must obviously be the lifters bleeding down right?? If the lifter did in fact not hold pressure internally, there would be a clacking then too. The poster did not mention it, but I did in my post, I said IF THERE IS NO CLICKY CLICKY...... Please read posts before arguing. Some of us do this for a living, we offer realistic approaches, not throw inane thoughts out and then argue them into a deep and sad world of personal pain and dissatisfaction.

 

sorry must of misunderstood him somewhere,

anyways, i worked at a parts store for a year and a half, also i maintian 10+ vehicles on my parents farm, sorry im not a computer network administrator who know all of cars and does that for a living

 

sounds interesting, i dont update my profile often enough, because i just recently finished my second college degree, and now hold 4 ASE certifications. I am no longer a NA, in fact, I see you are in central IL. I work for Green Toyota in springfield, IL. So, while I have never worked in a partstore, I have worked on cars my whole life, and do make my living working on them in a dealership. Could be where my rational thinking came into play here.

 

okay here is my logic for the lifter bleed down statement, i knew the motor had been sitting, lifters have a nominal 7 - 10 lbs of pressure, put 7 lbs of pressure on a full lifter and see how long it takes to bleed off, now even though the bore around the lifter will hinder the flow, i would figure that after a couple of months that the lifter could bleed down, ive had serveral cars like that over years that do that, generally they rattled upon start up during summer months, also i had a similar problem with my bird this winter, as i assembled the motor and when it wouldn't run i tried adjusting the lifters, after probably 10 minutes of cranking on it and it wouldn't run i pulled the valve covers, go figure the lifters had pumped back up, and the lash was way to tight,

btw where do you work at green?

 

Lifters always bleed down when the motor sits- and I don't mean for a couple of months, either. It can happen in just a few minutes or hours under the pressure of a valve spring on an open valve. When motors are first assembled there is often little or no oil in the lifter at all! THAT DOESN'T MEAN THAT'S THE PROBLEM. Oil pressure in the engine should pump the lifters back up to zero lash near-instantly when the motor fires unless the lifter or oil passages are gummed up. Any lfiter than has bled down and won't pump back up with DEFINITELY give you nasty valvetrain noises while running.

A rocker tightened down too far is a different story. It has used up all of the travel in the lifter's hydraulic plunger and bottomed out. Once it bottoms out any further tightening will start to lift the valve off it's seat and prevent that cylinder from building compression (and not firing correctly or at all). This misadjustment will not cause ANY valvetrain noise while the motor is running- it'll just run like it's on 7 (or fewer) cylidners depending on how many valves are tightened down too far.

I think it's unlikely that a valvetrain issue is to blame here (unless you hear valvetrain noise while running). If it was running right before being put away it didn't suddenly tighten itself down further while sitting for 3 months. I'd suspect ignition issues.

 

Rings are probly stuck.

 

Its a normal thing for the lifters to bleed down quickly after shut down. Oil pressure supplied by the oil pump is there for them. Adjusting lifters can be arealpain for people because of this, it takes some practice to learn the touch to get them right, without getting them too tight. As you can tell, I dont sell cars or parts at green, so that leaves one other choice.

1320--I doubt the rings are "stuck" either. care to elaborate your theory?

 

I tried screwing with the car a little this week end but didnt have much luck. I will give my scenario one more time. Got the motor last april installed it july and I broke the cam in and the car ran fine no issues. I started now and again until the end of october and it ran fine. Its been sitting since the begining on last month. I pulled all of the plugs and let the motor crank over untill I saw oil pressure and reinstalled the plugs and started it for a second and it ran fine. Last week put on my new mighty demon carb started it and it wouldnt run unless I gave it gas. Went to the engine bay and #2 and #7 primarys on the header were cold everything else was hot. I heard no valve train noisebut I do have open headers with s pipes that racket dosent help. How would I be able to check if I dont have any spark if I cant get a hold of a OHM meter ??

 

Now that I am thinking of it I also installed a PCV on the passenger side valve cover and connected to the back of the carb. And the put a fitting on the back of the intake and hooked it up to the brake booster. And there's a breather cap on the drivers side valve cover. So that has also change from the last startup at the beging of the month. I use to only have a breather cap and a oil cap on the valve covers and the brake booster hooked up to the back of the carb. Could that be the cause ??

 

could be the booster leaking making a huge vaccum leak, making it hard to run at idle, but i don't see that making it miss on just two cylinders, did you check the plugs yet, they could be fouled bad, happens to me alot when getting an engine going, especially when changing carbs

 

jonmark1985 I think your right about fouled plugs. I checked them last night and there black and VERY sooty. I put new ones in and the car ran alot better and the primary tubes heated up. I think I have to make some major adjustments on my new 650 mighty demon. I am not so good with carb adjustments but one thing I do see is the fuel bowls and there are 3 lines on each sight glass. The primary is just about in the middle but the secondary is way over the top. Could this be some of my problem ??

 

i had a buddy who had problems with a demon on his 5.0 mustang, we wound up turning out four the mixture screws on the side, that helped alot, make sure you turn them out evenly, and if you get all messed up i believe you turn them all the way back in and then out one and half turns, check your book that came with it though,

btw what kinda plugs did you use?

 

those screws..idle mixture screws... guess what... useful only at idle

what jets are you running?

 

guess what 305, he had a hard time getting it to idle

 

I am using autolite #26 plugs. I will try the idle mixture screws and see what happens. Last night I figured out how to set the floats so my secondary and primary are a little lower now before they where above the third bar on the sight glass now there in the middle. And the jets are what ever comes with it I think its 71/79

 

id use some ac delco's in it, i only use autolites in my fords, just my opinoin

 

guess what the carb isnt going to have anything to do with the 2 and 7 not firing... and the car will run on any plug including autolites that also isnt the problem

 

sometimes when i mess with something on my car it'll foul random plugs generally i wind up changing the whole batch, they may just have been "weaker" plugs than the other two and the first to foul up

I don't know just trying to be helpful here and i don't see anything wrong with suggesting running an OEM plug in it

 

SpitotRs305 well if its not the carb what do you think the problem is ? I was leaning towards carb and the idle mixture screws not being right so there's to much gas and it's fouling me plugs. Me buddy aslo suggested to check my oil and see If It smells like gas and it does. So do I have a leak or what? No gas Is leaking out of the squirters .

 

Betting your rings are stuck. Unplug the distributor and SLOWLY pour transmission fluid down the carb wile spinning it over. Do this in 5 sec intervils for a few mins. Then plug the distributor back up and crank the motor and SLOWLY pour it in the carb wile running. Hold it at about 2K and if the RPMs start droping fast then you are pouring it to fast.

BTW you will need atleast 2 people to do this.

 

Your carb isn't properly tuned for one, but as to your main problem, have you pulled the valve covers to make sure you didn't bend the pushrods on the exhaust side of the two cold cylinders. If they were opening I would expect the header pipes to be hot like the rest. Since they're not, and your running open headers which would easily mask the noise the bent pushrods would make, it's plausible that that could be your problem. Also check the rocker arms to make sure they haven't become so loose that they spun off to the side. Just my

 

Where exactly do you think they are stuck? And why exactly do you think thate it would cause this??? This is crazy. DO NOT DO THIS!!

 

When a motor sits for a wile the pistons will sit on the side of the cylinder wall. If the ring gap is facing the right way the weight of the piston will push the ring togeather closing the gap. When the gap closes the diameter will get smaller not letting the ring ride the cylinder wall completly. Since compression is one of the 3 things you need for a cylinder to fire geaus what happends

 

Have we ever determined if the plugs were firing?

Put a timing light on 2 and 7 and see if it is flashing before you do anything else.

If they are not flashing change the plugs.

I have seen a plug go bad that would not cause a spark. If the plug is bad, like the ones from my experience, the light will not flash. The current will not find a ground and you get no flash.

I changed the bad plugs problem solved.

an out of tune carb is not going to cause the plugs not to fire.

 

I change the plugs and it runs mint now. Had a buddy go threw the new carb and there was crap in the neeedle and seat so gas was just dribbling out of the carb. He cleaned it out threw it on his big block for some quick adjustments and now the carb is back to normal. Stupid fouled plugs.