[1989Gt.]

So yesterday i put a intake spacer on my manifold its a cobra intake, anyways I put it on had some trouble at first but when i got everything bback together, went to start it and now it wont start it starts up but dies right after it gets to about 1100 rpms. I dont get why it would do this....

[flattusmaximus78]

Tear it back apart....

[1989Gt.]

What do you mean....

[95tbirdv8]

Something has to be unplugged

[chickenbot]

are all your vacuum plugs on the bottom of the pletum pluged in?

[1989Gt.]

Yeah everyone of them are plugged in it wont hold a start at all

[1989Gt.]

OK i dont get it i put the spacer inbetween had to pull the dist cap off the top mani bolts pulled it apart slipped in the 1 inch spacer put the bolts through and put it back in and now it fires up for 5 seconds and turns off....

[jessemachone]

vacuum leak. i bet if you cover your intake at the throttle body with your hand, it will run better. i bet one of your vacuum lines fell off or broke off while you were doing your work.

you could also close yout throttle plate a little more to see if it improves things - if it does, you have a leak.

[flyin ryan]

did you use gaskets between the spacer and intakes?

[1989Gt.]

yeah one on each side of the spacer so vacuum leak can cause the car not to turn on too much air or what?

[93hatch]

yep

[1989Gt.]

cause this is gonna sound stupid but i cracked a lil crack on the flange on the manifold... Could it be sucking to much air at the start?

[95StangMX]

a little crack? what do you consider little? Probably better if you can post up a pic, I was going to agree on the vacum line getting broken or not hooked back up but if you cracked you intake that could be a problem is it popping when it does run for those few seconds? Is it running rough? Sure you got the dizzy set back right, and firing order is right?
Why were you putting an intake spacer on in the first place?

[1989Gt.]

Well the intake spacer went on because im putting new valve covers and 1.7 rockers on pretty soon and i just wanted to throw it on, as for the crack its kinda big now that i look at it i didnt notice it but now i am. Its not starting long enough to hear anything it starts winds up to like 2000 rpms doesnt hold and engine cuts off. I think its the crack to be honest

[95StangMX]

Yep going to need it to clear the covers huh? Well not 100% that the crack is your dilema, but it does not sound good, any way for you go get a pic? Hopefully (if you are lucky) it is in a place where it can be welded fairly easy, don't freak I am sure that if you have a good machine shop around that it can be fixed no matter where its cracked, just might cost you a little bit more depending on what kind of labor/machine work is involved....if pic is not possible where is the crack and how big? Did you double check all the other stuff like vacum, and dizzy, and firing order, to make sure you got it all back where it was at?

[1989Gt.]

Well i didnt pull the dizzy out the only thing i did pull off was the cap and rotor, but i left all the plugs on it to. Can a shop fix the crack its cast iron you cant weld that.... i thought? i have ran through everything i can think of outside looking at it it all seems fine except the crack (and i bought a brand new mr gasket spacer for 10 bucks thats why too)

[95StangMX]

It can be welded, not always the easiest, have to put it in oven an use a special rod, don't know, may be cheaper/easier just to get another one. Guess it really depends where the crack is, and how bad, You may even get away with JB weld I have seen someone use JB on a cracked block, and also on a craked head before, it was at the dealers auto auction, someone trying to hot patch them and keep them running long enough to roll through the auction block, a friend bought and resold it very fast so dont know how long it lasted, he drove it and beat the shit out of it for a week or 2 and put it back through cause he didnt want to sell it off his lot, but it lasted through a couple of weeks of hard abuse....haha

[93hatch]

jb weld ftw

[1989Gt.]

My dads a good welder so he said he can fix it for me he said its not hard just gotta do some cool techniques ill let you guys know how it goes tomorrow or whenever i can get him to do it.

[95StangMX]

Its not a matter of being a good welder, I consider myself a damn good welder but when doing cast iron or cast aluminum, there is a special technique you have to use, I am not 100% sure of all of it, but do know it consists of baking it in an oven and using a special rod, and its not easy, also depends where its at.
I have an old 1957 Iron Head Harley Davidson and they were notorious back then for the timing chain getting loose and slapping the cast aluminum case and cracking it, causing it to seep oil, I could not find another case cause it was so old and pretty rare so I took it to a guy that does a lot of machine work and builds drag bikes and it cost me some pretty serious coin, I mean as far as welding goes (close to a grand if I remember) but he also had to have special tools to split the cases, and he cleaned it all up and it looked factory when he was finished....

Just telling you this so your dad doesnt just try and weld it like normal.....Let us know how it turns out and post some pics, would like to see how it turns out. Good or bad either way, cause its not as easy as it sounds.....
If its not that big, and not in a critical area, I would probably JB weld it and call it a day, and if it doesnt last then try welding or replace it....