Hey if anyone can help me with my problem i would thank them 100 times....was planning on going to the track tommorow but will not be because of this. i put and edelbrock intake on my car last week and it had horrible vacuum leaks... i took it off then did it again with edlebrock gaskets and was really careful no vacuum leaks this time but to find out i had coolant pushed out. I tore the heads off bought some used GT 40 heads put them on new gaskets adusted the rockers to spec. put my intake back on. i have minor vacuum leaks because of striped threads in the lower intake for plenam .....not terrible so it does not make sense why i have absolutly no power... when i had the vacuum leaks last week i had tons of power... the times has been set between 10 11 12 13 14 and no difference it also back fires terrible when it first starts have a scan tool and no codes other than ac clutch signal i know the vacuum leaks and exhast leaks need to be fixed but i cant move forward at all because my intake is such a piece of shit.... im going to buy a cobra upper and lower tomrow to hopefuly solve the vacuum leak problem but if anyone knows anything specific of what the problem could be please fill me in.?
That sucks i told you you would have problems with that old edelbrock when i pciked up the systamax you should of baught my cpbra ill give oyu a good deal.
http://autorepair.about.com/library/firing_orders/bl-fo-9834.htm if that is correct i have the firing order wrong -i have it for the non HO motor michell on demand did not give me that order
i cant touch this thing anymore i keep fucking with the timing i keep getting somewhere wher ei think its gonna be right and the back fire is going to break something in a hurry im afraid if i touch it anymore im gonna do more harm than good
Buy a helicoil kit for the lower intake. Fix the stripped threads. You can't put things together with stripped threads and expect to have a leak free seal. A lean missfire from the vacume leaks will cause it to run like crap. Take a comnpression test to see what the cylinder pressure is like. To see if the valves in the used heads are sealing. Maybe you have the valves too tight. This will also show in a compression test. You have your work cut out for you. Some more diagnosing is to be expected.
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337 C.I.D.
390 R.W.H.P.
362 R.W.T.Q
11.44@120 in the 1/4
7.35@ 95 in the 1/8
1.60-60'
N.A.
1988 L.X. Hatch 5.0L 5-Speed, 85,000 original miles
i corrected the fireing order and now it will not run at all and all it does is just pop really loud im afraid i will break a valve. im switching my edelbrock intake to a cobra upper/ lower that is brand new. i was also thinking the valve are not seating but it will not run at all now and it would run shitty when i had the firing order for the non ho motor im not sure i dont know what im doing and i need someone who does.
The H.O. firing order is a 351 windsor firing order ... H.O. 5.0L - 1-3-7-2-6-5-4-8 in a counter clockwise rotation . Make sure when you dropped the distributor in that the ignition rotor point's in the viscinity of the number one terminal on TDC . You could be 180* out . The balancer should be pointing at "0" when the #1 piston is @ TDC on the compression stroke . You also could have bad valves .... This can be verified with a compression check . Also when you say " backfire " ... Is it out of the tail pipe or out of the throttle body ?
One other thing to look for to is MAKE sure you didn't pinch any wires between the lower intake and the engine during assembly . I've seen this happen to people a few times .
im pretty confident there is nothing wrong with the heads i have and it seems to be backfiring out the throttle body... no wires have been pinched ive pulled the intake like 10 times trying to fix it it seems to have good compression i dont have an adapter for my tester because of the style head. when i ran it on the non HO order it would at least start....now it wont, thought i had it fixed when i found out my order is wrong......is it possible my block is from a carbed car and have that firing order? if anyone has any tips please call me 617 688 4236 i would like to get this figured out as soon as possible.....the reason i replaced the heads was i blew a head bolt off and anti freeze was pissing out of where the head and block meet i dont want to backfire it and break a valve or another head bolt so i will probably wait until someone who knows these cars well can help me
well i dont think i can help you but i do want to say, when me and my uncle put together his 86 conv. all we did was change the motor and put a 302 out of a t-bird, he self ported and pollished e-7's and put a explorer upper and lower on.thats it nothing else. now its very hard to start(hafta spray starting fluid in it) and when it does start if u mash on the throttle it back fires through the intake. i have yet to find the real problem so now it sits. my dodge ram backfires through the intake when i drive it on somewhat warm days, never on cold days.
#1 how the hell do you blow a head bolt off? unless they are ARP's, I think they are torque to yield bolts...can only use them once #2 if it at least ran with non-HO firing order, go back to that to at least get it running #3 smash Eddie intake with a hammer & put Cobra one on #4 report results
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Death is my art and I'm about to paint my masterpiece.
well after having all the confidence in the world lost im going to pull the intake make sure my valves are adjusted correctly and chance my firing order around until it runs again....i do have to say if it runs on a non HO motor i will be puzzled
^^^^ dont tempt me im very close...good news thanks to everyones help i motivated myself to go down and fuck with it one last time fired right up got a lot of issues i need to take care of making sure rockers are adjusted correctly, fixing dipstick leaking everywhere, and swapping my intake....took for a ride feels shy of about 100 HP really dog lower end power. well see ill let everyone know as i will probably need more help
im pretty confident there is nothing wrong with the heads i have and it seems to be backfiring out the throttle body... no wires have been pinched ive pulled the intake like 10 times trying to fix it it seems to have good compression i dont have an adapter for my tester because of the style head. when i ran it on the non HO order it would at least start....now it wont, thought i had it fixed when i found out my order is wrong......is it possible my block is from a carbed car and have that firing order? if anyone has any tips please call me 617 688 4236 i would like to get this figured out as soon as possible.....the reason i replaced the heads was i blew a head bolt off and anti freeze was pissing out of where the head and block meet i dont want to backfire it and break a valve or another head bolt so i will probably wait until someone who knows these cars well can help me
-- Edited by mikefheath87 at 17:54, 2008-04-06
For your information ... you should never get a backfire through your throttle body . Unless you have a bad intake valve . Because when the plug fires off ... the next thing that happens is the exhaust valve opens . If your getting " popping" through the throttle body ..then you have an intake valve sealing problem .. the valve or valves are either bent or the seats are burned causing the valve NOT to seal correctly and there for causing the combustion to come back out of the intake instead of staying in the cylinder .. You bought the heads used corect !! So how do you really know that they are in good working order ? Unless you brought them to a machine shop for inspection ...you really don't ! IF your engine has a roller cam and hense roller lifters.... then it's a H.O. firing order .. You need to take a compression check on all cylinders and note each cylinders compression out come . Especially since you say it's doggy ... why you ask .... UMMM LACK OF COMPRESION !!! I will bet you anything that you either bent a valve during the assembly proscess or they were already damaged when you got them . TAKE A COMPRESSOIN TEST AND ALL WILL BE REVEALED !!!!
car is running a lot better my compression tester does not fit into my particular head. i think when i swap my intake, put the correct mass air, adjust the rockers, fix the exhaust leak i will be well on my way...and i believe the back fire was from incorrect timing.....ignition spark while an intake valve hasn't closed yet?? oh well ill fix the other problems then i will probably do a compression test to be sure everything is ok thanks for the help everyone.....ohh and if anyone knows what kinda compression test fitting i need for gt40 heads let me know
ive seen this a hundred times it probely has plugs for stock heads the gt 40's take a longer plug more threads your spark plugs are not even in the combustion camber put autolights in it
ive got the car running great......i did loose the bolts for my new cobra intake so i used threaded rod and i know that sucks.....i sold the edlelbrock before it even came off the car. i still have an exhast leak i cannot get to seat up....think maybee my headers are fucked up or something? oh well fixing that should be easy
also what do you guys do for pcv system or breathers my ol cap blows off and i dont want to create a vac leak with reathewrs and i have no clearence in my valve cover holes
yesterday is history tomorrow is a mystery
337 C.I.D.
390 R.W.H.P.
362 R.W.T.Q
11.44@120 in the 1/4
7.35@ 95 in the 1/8
1.60-60'
N.A.
1988 L.X. Hatch 5.0L 5-Speed, 85,000 original miles
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