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Engine not running happy upon first start up

12K views 73 replies 15 participants last post by  evilbeef54 
#1 ·
I have a small block 350 4 bolt main, that we changed all the seals on and put a new Comp Cams cam and lifters. It also got a new cap, rotor, and wires. the old edelbrock preformer intake, Edelbrock 1406 600 4 barrel Carb went back on. The truck also is getting a whole new painless wiring harness

On first attempt to start up it didnt want to fire i removed the distributor and made sure it was inserted correctly with the #1 cylinder at TDC rotor pointing at the #1 cylinder, #1 wire on that post and double checked the wires were on in the right order. After that it fired right up, tried bringing up the rpm to 2k for the break in and i am getting some LOUD backfiring through the carb at about 2K rpm. I shut it down and reset the idle mixture screws to 1.5 turns out each and made sure the air filter was on tight. It started happier but still backfires through the carb at 2k rpm. Also after turning off the key one time it kept running, for a few seconds.

I would like to get some suggestions from you guys on what else to check/inspect/additional info you need. This is my first cam swap and want to get this thing broken in correctly. I'm not trying to tune for performance or anything right now, just want to be able to have it running at 2k rpm so i can break in the new cam
 
#49 ·
just had a thought . not sure how yours works but my dizzy ( not being used now - only to drive oil pump ) has a helicol drive cog which locates off of the cam. if that is buggered or the spilt pin is screwed it may turn for a bit but then fire wrong due to the spilt pin or dodgy teeth on cog etc etc. put a rag around the cog and try to twist gently with the dizzy locked. or best still replace with a new pin to be on the safe side,
 
#51 ·
i had just pluged the vac to see what the initial timing was, did't matter the vac advance didnt work anyway, plus everything was out of adjustment, and gummed up, the weights were sticky opening and hung up when closing. I picked up a MSD pro billet, 6a box, blaster coil, and wires for a great price off a local craigslist find, it is in GREAT shape but it had the big 7445 pro-cap and rotor kit on it which was about 1/2 inch too big (not enough room with the firewall on the truck) soooo i am waiting on a new cap, rotor, and vac can, and weights/advance kit (he had it locked out) from summit. Even with all that i still got a good deal, everything looks barely used. Will try again on monday when the parts get here, but from the condition of the old distributor it really seems like that is the issue.

thanks for everyone's help and patience, hopefully this is the magic fix.

anyone wanna buy a big MSD pro-cap kit, like new :thumbup:
 
#52 ·
Hi



I would like to thank all the guys here for helping me build me 350 TBI engine

I had the same problem with you:cool::cool:and it's comp cams fult


I have set the timing on 0 and when I try to crank the engine it's backfire from the throttle.....I thought it's need a spcial degee or something.....but it's won't start:confused::confused:


finally I after 2 weeks of trying I found the problem...it's the comp cams timing gear #2100

it's give you a totally diffrent degree of the 350 engine

usually when you matching the two points on the timing gear the piston #1 must be on TDC "new lesson to me:D" but with comp cams when you matching the points the piston #1 is going down with open intake ..or intake stroke and that's why it's back fire when you try to crank the engine


comp cams is junk is poeple say and now I belive they are junk

it wasting me the money-time-work so you should match the old parts with the new :)
see the diffrent between the comp cams gears"left" and other brand with a correct timing "right"


I try the free host but won't work...so I upload the picture in my flickr account

comp4re | Flickr - Photo Sharing!


good luck and contact the comp cams....I think they replace it ...I,m not yet contact comp cams yet
 
#62 ·
VICTORY!!!!!


sort of...


Got the new MSD pro billet distributor, 6a box, blaster coil, and msd wires in... fired right up, came up to 2kish rpms smooth, sounds great, but the old crappy tach i was using didnt read off the tach port on the 6a box plus it was a bit late so i shut down... as i shut down i saw a white flash from somewhere out side....

main 70 amp inline fuse blown... several others on the block blown... the good news is the motor started and ran and sounded great and i just have a lil electrical issue that once i track the lil punk down everything should be running great
 
#72 ·
I like to keep the plug wires the way they were from the factory, just for the convienience of some future schmuck who is trying to tune a car. Chevy used the post just clockwise of the points window as #1 for all points distributors, so that's where I leave them. On the HEI they used your #2 view, so I leave them that way on HEI systems as well.
We can change them up and have #1 anywhere, as long as the wires are hooked up in the right order and the rotor is pointing correctly, but it still can cause confusion in the future when somebody replaces plug wires and puts them on in the "normal" position and the engine wont start again. I've seen it happen unfortunately, and it took some time to figure out what was going wrong.
 
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