so ive been working on an 83 gt with a 302 out of a 89 grand marquis. It has the hei upgraded distributor with new wires and plugs its missing interminently on 4 6 7 cylinders the pipes on the headers wont even get hot to the touch very weak spark on only those cylinders. ive checked plugs gapped them to spec for the hei checked intake and carb base for vacuum leaks replaced plugs thinking maybe got bad ones. switched wires on them cylinders to see if it would change it didnt. checked timing checked grounds replaced cap and rotor tested the module in the distributor. plugs look normal after driving around. ran a constant 12 volts from battery to coil to see if it was that and still nothing so im stumped havent done a compression test yet cuz i dont have a tester. any ideas or things to check are welcome please help.

Might need to check firing order, compression and maybe the injectors. FYI the 5.0's had two different firing orders (H.O. and non H.O. )

Firing orders are
H.O. 1-3-7-2-6-5-4-8
non H.O. 1-5-4-2-6-3-7-8

it ended up being an intake leak on the inside part of the gaskets it was sucking oil in. thanks for replying though. its my buddies car weve been fighting it since hes got it now we got it running damn good next spring time for body work.

Glad you got it running.

I have 3 explorer/mountaineer uper and lower intakes. 1 non egr and 2 w/egr. i also have the hardware too. these have allready been chemically cleaned. let me know if you are interested.

its carbed with an edelbrock performer intake

i know they are, but i meant if you ever wanted to go FI, let me know.

Glad you guys got the GT figured out. I love them four eyed Stangs'.

Any pics of your friends car?

heres the only pic i have next to my 83 monte carlo ss

it also only had 6 volts going to the hei coil so we found a keyed constant 12volt and the spark issue seems fixed too and its an 82 i was incorrect on that part i woulda known if it was mine lol

oh and the flat black paint job is mine too haha its a $25 krylon parking lot job what yalll think haha

I like the classic 4 eyed stangs. I had a modified 89 GT. I learned alot on that car when doing mods. Glad to see you got her figured out!!