heavy_chevy29

this spring i put a scott shafiroff 434sb in my car. i finally got it streetable by mid summer. this cars been nothing but a pain in my a$$. i know its not the motor(i dont want to bad mouth scott shafiroff). its been a bunch of little things. first it wouldnt run worth a crap, but i did alittle tuning on the carb and it ran awsome. the the msd box crapped out. i sent it back to summit and they gave me a brand new one. i put the new one in and it ran even better that it did before. then on the way to work the gasket on the back of the water pump went on me. so i had the car towed back to my house and fixed it the next day. after that i had no problems.

then one day a friend of mine called me an asked me if i could run over to his work and help him out. i was in the middle of doing a service to my truck so i had to take the camaro. so i go to start it and its taking a really long time to fire up. then it finally starts and it ran fine. i get to his work and another friend asked me if i could take him for a ride. so i go to start it up. it does the same exact thing. once it starts it runs fine. ever since then it hasnt been the same. it always takes 4 trys to start it, no more no less. on the first try is kinda hickups through the carb and smoke comes out from under the hood. the second try it will almost fire. the third try it will crank but not start. then on the 4th try it always starts. this isnt just one time. thats the routine that i have to go through to start it every time. then when you shut it off it will deasil(sp) for a second or two(not all the time).

this is what ive tryed to fix it. i tryed re-adjusting the crab and got nowere. then i took 4 degrees of timing out of it. i check all the ignition wires and they were fine. i check fuel pressure and i have about 7-8 psi. i rechecked all the wiring for the msd box and that was fine. everything i did got me nowere. no better or worst that when i started. a couple of people told me that i should try another type of ignition box so i ordered a mallory 6AL box. i installed that today and now it wont start at all. it just hickups through the carb. i looked though mallorys trouble shooting guide and narrowed it down to what i thought was a bad coil. i go to the parts store pick up a coil, put it in and its no different. if anyone has any advice please help me out. im getting to the end of my rope.

i know its no the motor because when it does start it runs awsome. thats what has me so confused. its just when i try to start it. once its running its fine. i have no idea what the hell i should do. its driving me insane.i have $11000 in the motor alone and i have only been able to put alittle under 200 miles on it this year. please help me out. thanks and sorry for the long post.

robertfrank

iTrader: (27)

do you have an electrical fuel pump or a mechanical one?when i had my 87 ta i kept having the exact same problem before my mechanical pump took a dump.if thats not the case then i`d say check your fuel filter because to me this sounds like a fuel problem.but i could be wrong.

heavy_chevy29

its got a holley mechanical fuel pump. i know thats its going to need an electric pump later on. i was trying to save money but now im so desparate that im just replacing parts to see if i get anywere. and im just going broke with no results. if anyone is interested in the car please pm me with any offers.

chevy35086

sounds like the timing is off a tooth.

heavy_chevy29

i dont know how that could be. the motor has 200 miles on it. everything is new.

heavy_chevy29

well i have no spark. i tried using another spark plug that i know is good and that didnt work. tried another good plug wire and that didnt work either. i tried repalcing the coil and that didnt work. so i tested the magnetic pickup in the distributer and i got 1100 ohms. on the msd web site it says that 400-1300 ohms is acceptable. so the distributer is good. then i checked the harness from the distributer to the box and that harness is good to. this is really driving nuts. please help me out.

SaintedCorrupt

there must be something in between the box and the plug thats messed up. I dont know how the digital ignition works, so all i can say is check the basics, like makin sure all the plug wires are in the right firing order, no burned plug wires, proper plug gapping, the right kind of plugs, and that kinda stuff. there's something in there thats stopping spark, and youre just gonna have to follow the path with a probe until you find the problem. resign yourself to the fact that youre probably gonna have to be under the hood for a couple hours, just chasing wires.

hook up a timing light to test that the spark plug wires are getting fire. you dont wanna play poke-the-wire with that much voltage. test it right at the distributor and right before the plug for a break in the wire.

wellington

after reading the posts on this forum,one common theme arises.

msd boxs are crap. every time someone has one of their boxes .their posts are allways about how their msd messed up somehow.

i have also heard msd is crap from various other forums.


id say,dump the msd .

and go back to just an upgraded stock.

brutalform

When I had my old 355 in my car, it went its fastest WITHOUT the MSD on it. It stopped working, and I removed it. Go figure.

I had a similar problem that you are having. My problem was the distributor itself. There was play in the shaft. Not the side to side wobble, that is the common problem, but, the up and down movement was too much, and the shaft was coming up and causing the rotor to rub on the inside of the cap. I figured the reluctor was getting to far away from the pickup, so I borrowed another distributor, from a buddy, and the problem was fixed. This of course was after I replaced the pickup, module, etc.

brutalform

By the way heavy, what kind of numbers does the S/S engine make?

brutalform

OOPS, I just saw your sig.

heavy_chevy29

thanks for the info guys. the motor put down 576hp and 582 ft-lbs at the crank.

Jerry Davis

Mr Heavy Chevy, What kind of induction are you running to get these nice HP numbers and at what RPM? Thanks, Jery

heavy_chevy29

i dont know some if the parts because i didnt build/order any of them. from what i know it has a victor jr style manifold, 1/4 plastic spacer(i think), a 950cfm demon carb, and brodix 220cc heads. it makes peek hp at 6200rpm. peek torque is 4600rpm.

brutalform

SWEET

Jerry Davis

But thats above our 5000 rpm self imposed max, we are looking for 500 HP+ at or below 5000 which is why I am mucking around looking at long runner systems. If wishes were horses I need a 19 inch run from the plenum port down to the intake valve seat with an ID of at least 1.9 inches, with 2.25 by 1.25 port at the head.

The stocker TPI's and some / maybe all of the aftermarket long port varieties are more like 23 to 26 inches as far as I know at the moment. Dynomation says I lose almost 30HP when I go to 23 or more inches from the 19. But torque is good of course especially down low. Miniram styles look like they can make the 500 at 5000 but the torque goes in the toilet by comparison in lower rpm ranges.

Still searching for real dyno info on a 414 ci sbc using the various TPI manifolds, in the end thats where we will figure things out.

Have lots of mail out to various companies and Ken at FIRST remains the most helpful of anyone to date, great guy to work with, really goes out of his way....J



Still think the first manifold might be best.

flaming-ford

iTrader: (7)

have you gotten anywhere with this?

Basically everything you've done would be what i reccomend but, just for the heck of it pull your cap and check the rotor on it make sure it's not bent or rubbing like the 1 user said due to up and down play.

Other than that g/l sounds like you need it and don't give up!!!

heavy_chevy29

believe me im way past giving up. im giving serious thought to parting the car out.

1983Fbody

I bet you.. go to the junkyard, pull the first HEI you see, pay maybe 15 bux for it, bring it home, drop it in, hook one wire straight to the battery and your up and running.

Either that or the engine isn't grouded? That's easy enough to check just clamp a set of jumper cables between engine and chassis..

I've also had a no spark problem because the three wire plug in between the coil and module was corroded/ loose. Your distributor is probably gutted though, I'm willing to put money on a bad ground somewhere or your IGN lead isn't supplying juice. Try running 12v straight from the battery to the IGN and 12v leads on your spark box. I'd also double check for a good ground to the spark box.

SSC

Ive never had problems with the MSD boxes. I just dont think $200 is well spent with one on a street machine.

I second the HEI! Grab a bone yard unit or spend the $130 on an Accel and sell all the other ign pecies and recoupe some lost fundage.

heavy_chevy29

well i took the mallory box out and put my msd box back in. the car will start but its just the same as before. its hard to start and some times it will deasil when you shut it off. other than that it run fine. i took it for a ride and it drove great. i mounted the box inside the car this time and i noticed that the box makes alot of noise. is this normal.

1983Fbody

Did you check for a bad ground? I really think your problem is something with the box not getting good power/ or ground. This should be easy enough to check with a good multi meter, like I said I had a similar problem. There was no spark to the engine, if I touched the spark plug to the chassis of the car it would complete the circuit and VIOLA! spark and it would start right up! turned out to be a ground wire. ALmost 90% of electrical problems are ground-related (according to the "how to wire electronics" hot rod book). I really think you'd have the problem solved already with a few simply tests using jumper wires/ swap distributor/ multi meter. It's not rocket science. I might have said this already, I'm just trying to help. Sweet engine by the way!

brutalform

Yea, whatever you do, dont part that car out. Dont let a small setback get you down.

JP86SS

iTrader: (1)

You may have tried this but I figured I'd mention it in case you missed it. If you install a diode in the system, it may eliminate your run on problem.
It is detailed in the installation instructions of the MSD.
I do believe you have a grounding problem on the unit too because at low rpm you should have plenty of multiple sparks.
I hope you can get past the frustrating issues.
Does sound like one nasty ride