Hey guys I have just completed buildin my Vortec headed 353 TPI. But when it came time to fire it up last night all it did was spin over and back fire. It never once sounded like it even attemted to fire. I lined up my timing marks on my balancer, checked rocker location makin sure they were both closed, verified pistion location, and had distributer aimed at 1. So I thought I had the timing right, but no dice. So I have mover the distrib. gear back and forth so many times in different locations to see if I was off a little bit but same ole situation. Never fired and just back fired. I an getting fuel cause there was a puddle under the headers. I dunno what fuel pressure is right now but I should be able to get a gauge monday. I have spark, I checked all 8 wires and all have spark. So I am at a complete loss as to what to do.

Questionable problems--->

#1 I removed all my EGR peices. Valve (under the plenum), Solenoid and installed block off plates. Now the solenoid had to vac hoses on it. One that ran from the valve to the solenoid its self and another that ran to the bottom of my Throttle body. I currently have the TB plugged off with a cap. And all the way down to the fuel canister that one is blocked off also. What is ur take on this?

#2 Do all cam gears bolt in the exact same spot on stock cams as well as aftermarket cams? I installed a TPiS torque secrects flat tappet .500/.500 lift cam in and lined up the marks exactly to where they were when I pulled the other cam out. The marks were not lined up to each other but I just a little off from each other. But I did get the gear to line back up in the same spot as it came out. My concern is, is there a possiblity that the cam is not in the proper location. I think it is cause the rockers are closed when the timin marks come around and the rotor is aimed at one.

#3 Stock chip. I still have the stock chip from the 305 TPI installed and thought I could get away with just firing it up with the stock chip. I have a guy comin out to burn me a chip but I wanted it to run for him so he could see and tweek it.

#4 Rocker lash. I tightened the rockers down till the rockers had no lash then went one full turn. I got these instructions out of the computer softwear at work. Its mitchell on demand 4 and thats what they told me to do. Is this to tight. I read a post earlier that only a half turn is what u want. And any more is to much.

#5 Slow crank over speed. The motor seems to crank over slower than normal. I'm guessing its because of the high compression I have. about 10-10.5:1 I'm also trying to fire the car on 92 octane pump gas.

I would love for u guys to help me out here! I'm goin to try and losen the rocker arms a half turn and connect my TB vac hose to the canister and see what happens.

Mods are in my sig!

Jason

 

There is two TDC positions. You might have lined up your distributor with the wrong one.

Pull your plug wires off the cap and put them back on 180* offset from where they were. That means the wire from the #1 terminal (cap) will now go on the #6 terminal (cap), and the #8 will go to the #5, etc... until they are all 180* offset.
If it starts up and runs after this:
This will tell you if you installed the distributor 180* out of phase without having to pull and reinstall the distributor.

If not then continue troubleshooting.

 

Same exact symptoms I had last year when I put everything back together. Like 305sbc said, I was 180* out. Try that first.

 

I did try going out 180*... by moving the distributer but just backfires and no start.

 

OK I just got back in from hookin the vac hose back up to the TB to the fuel canister, and taking half turn out of my rocker arms. It still does nothing besides back fire. I even switched my plug wires 180* and still nothing. What else could it be?

 

When you moved the distributor you pulled it out and reinstalled it 180* out? You actually did this? Is it still in that position?

Did you try a different set of spark plugs?

Other possibilities could be cam timing off, dead plugs, or ignition module. Is your coil grounded good?

 

this may sound stupid but make sure you have the plug wires going the correct direction on the dist. i did this recently with my winter vehicle. and it fired right up when i got it right.

 

I did pull the distributor out and put it back in 180* but no dice. So I moved it back to face the #1 position. Also I would assume that my coil is grounded good but how can I be sure?

I welcome stupid ideas right now cauise it could be something stupid. But yes the plug wires are goin the right direction and in the right position. 18436572 man I got that memorized

My plugs are brand new Champion plugs gapped to .45 so those should not be an issue.

Tonight I pulled the timing cover and reset everything back to TDC on #1 and set cam gear to #1 timing mark. plus lined crank gear timing mark to the top. And also put the distributor in the #1 position. So all is timed at the #1 cyclinder. I will have everything put back together and tested late tomorrow night. So u prolly wont hear from me till then but keep suggestions comin!! I will not stop until this is figured out

Also the cam timin all looked to be right but just so I knew it would be right I reset it.

I also have another question on how to know which injector connector goes where and if theres away to find out when each fires so I know that I have the correct connecter on the right injector.

Thanks guys
Jason

 

Back firing is because the timing isn't right.

Try to follow me on this.

The #1 piston (and all the rest of them for that matter), are at TDC TWICE.

Once on the compression stroke and once, again, on the exhaust stroke.

You must make sure the #1 piston is on the compression stroke. That's the first thing to do.

Remove the #1 spark plug, stick you finger over the spark plug hole and have someone bump the engine. When you begin to feel pressure, the #1 will coming up on the compression stroke.

If you are alone, you can stick a piece of rolled up paper towel into the hole and when it blows out, you're on compression.

Now: As you begin to feel compression, start watching the damper. You want to stop bumping when the mark on the damper (harmonic balancer) is aligned with 8 to 10 degrees BTDC. That will be the numbers on the timing tab that are toward the passenger side of the car.

Stopping there will give you approximate initial advance enough to get the engine started and running. Replace the plug and wire.

Now, remove the distributor cap and see where the rotor terminal is pointing. It should be pointing at the #1 spark plug wire; if not, remove the distributor just enough to turn the rotor. Turn the rotor to a position that will make it point at the #1 wire when the distributor is installed FLUSH with the intake manifold.

This may take a couple of tries to get right.

If you had to remove the distributor to turn the rotor, the distributor and oil pump drive will no longer be in alignment.

There are two ways to handle this: The easiest was is to just bump the starter with the distributor installed in the intake as far as it will go. At some point in the bumping the distributor will drop down flush with the manifold.

The other way is to completely remove the distributor, use a long handle screwdriver and turn the oil pump drive shaft until it is in a position to mesh with the distirbutor shaft. #1 is much easier and is the one I ALWAYS use.

Plug wires, as you said are 18436572 but mush be installed in a clockwise direction in the distributor cap.

When adjusting lifter preload, you cannot just tighten them down after finding zero lash. Each camshaft lobe MUST be on the base circle, not on the ramps or nose of the cam. I have a file I can send you on how to do this (if you need it) which makes adjusting lifter preload (valve lash is a mis-nomer for a hydraulic camshaft) really easy.

Hope this helps.

Jake

 

Thanks Jake for all the great info. I have done everything that you have mentioned execpt my timing marks are at 6* ATDC is that bad? I can always pull the motor back to 8* BTDC. As of right now its at 6* ATDC and the distributer is just on the #1 postion. What do u make of that?? if it needs to be brought back one tooth I will do that and I have no probmlem pulling out the distrubter and adjustion the oil pump w/ a screw driver cause that how I have always done it. Also my cam is timed straight up and down at 6*ATDC. what do u think

Jason

 

Recheck your valve adjustment.

 

SHES ALIVE!!! Rippin it down to the timing chain and seting it there worked!!! I set the crank timin mark straight up and then lined the cam gear up top (180*) from the crank gear.) then set distributer to the #1 and put everything together and vroom vroom....so thanks guys for all ur help!! now I just got to tune it!

Jason

 

No, having it set at 6* won't make that much difference; it'll fire there as well.

Jake

 

Hey!!!! Glad to see she's up and running; congrats.

Good luck with the tuning; the fun has just begun (lol).

Jake

 

Yea I bet this thing isnt goin to tune for anything. But she seems to do all right so far. I think that I will fork over the money and have TPiS tune it if the custom chip I'm having burnt doesnt work well. But she screams as of right now...Settin the rocker arms sucks cause I cant turn the motor by hand so I have to hit the key each time and I never get it quite right. Oh well they are good now...

Thanks again
Jason

 

You can buy an inexpensive bump starter from most auto parts stores. Clip it to the starter solenoid and you'll have bumping at your fingertips.

Other than that, you'll need a friend to get it right.

BTW, please don't fool with TPIS for PROM burning. I've had two and they were awful and other guys who have posted on other boards about them have had the same experience.

Ed Wright is the guy who is one of the PROM gurus. Good reports on all his PROMs.

Jake

Jake