87mustang347

what mods do u have on the car. u didnt really specify. did u get a summit kit for ur clutch or a summit engine rebuild kit. what else do u have besides the cam. a big part of that is that ur speed density. i had the same problem when i started to do heavy modding and i got a maf conversion kit right away and it fixed all my idling, a/f problems rite away. i think thats what ur gonna have to do to. sd cars respon very well with basic bolt ons and u mite ieven get away with a mild cam if that alll u have(like u said u had) but with any type of cam on top of other mods with no maf or tune, expect for the worst. my suggestion is, do what md said and if that dont work then do what i said. get a maf conversion kit. ur problems will be solved

Dbeck002

SD isnt made to handle mods very well. you should convert to MASS air before going any further. Then of course you could retune your SD system but that costs $....


IMO convert to MAF and then come back if you have some more problems...


later dood.

Justanother5.0

I would take mdv's advise... doing a compression check is easy and will help you emliminate the mechanical aspect of the engine as a possibility... personally I would suspect cam timing as well.. especially since the car ran fine before the rebuild.. if your cam timing is off you'll likely have valves open on the compression stroke on some of the cylinders... and you'll have no compression.

Dbeck002

well compression is one thing, but SD doesnt hold up well with mods. that is probably the problem unless you got the SD tuned after all the mods. if you did than it could be compression.

mdvaldosta

no, because like was said earlier if the car ran well before the rebuild - and all the same parts were re-used - then the metering system shouldnt be a concern. all this is really trivial - sure their can be alot of things causing the problem - but he needs to start eliminating the potential problems starting with most likely to least likely - thats how you troubleshoot

87mustang347

what exactly are the mods u made b4 the build. im confused about this kit u got. explain urself

michialj

Thanks for all the help everyone. i will try to answer all of the questions.

the car is an 87 gt with a 5 speed. it is speed density. it has a little over 180,000 abusive miles on it.

Here is the situation. I have good compression on all cylinders, the diagnostic computer says that one is laying out, and it runs the about same without that one firing if you pull the wire.

lifters all went back in the right places, i will look for metal when i change the oil.

I haven't noticed any oil on top of the engine, but i will look in the morning. I can't tell you what type of stone i used to hone the cylinders, i would guess a medium one, but they seemed to have a good cross hatch pattern that has worked on every other engine.

I bought the sealed power rebuild kit from summit (who i will never buy anything from again, their service was horrible, but thats another story), it had cheap-*** hypereutectic pistons and sealed power rings. I really think all of that is fine, seeing as how my compression is good.

The cam is an e303 from ford racing, the same one that i took out before the rebuild. I stilll have both sets of cats and the smog pump. The only difference is that i cleaned out all of the stopped up ports in the heads so that it could do its thing. THe exhaust is just a couple of glasspacks.

Here is what i changed when i rebuilt the engine: TPS, plugs, wires, cap, and some sensor in the intake that i don't remember now...a temperature sender i think, plus all of the normal stuff that you do when you rebuild an engine, gaskets, seals, water and oil pumps, ect. Also, i ported the exhaust side of the heads just a little bit and polished them up. I did the same to the flanges on factory headers. I more or less left the intake side alone, except for a few places where a took down some flash left over from the where it was cast. Also, as i mentioned above, i unclogged the ports on the bask of the heads where the air pump pumps into the exhaust side of the heads. I also cleaned the carbon off of both parts of the plenum and all of that stuff. The old man gave the valves the workes (reground them and the valve seats before lapping them in.) Oh yeah, and one new generic autozone fuel injector for the cylinder that is running crappy.

I hope this helps, ask me if you need more information. i might try the fuel regulator thing, but i am going to stay away from MAF for right now, as $$ is an issue. I am a poor collage student, and all i want to do is be able to get my sorry self to the grocery store to buy some beer and smoke a few of those cars with a big wings and too many stickers along the way in my ride that cost less than their system. Thanks.

slo93aod

you have the firing order right? all sensor connected? all grounds grounded?

michialj

oh yeah, one more thing,

i think the cam timing is right, but how can i tell? i drive it daily and it doesn't seem to have the calliber of problem i imagine the cam being very far off would create. also the cam is set with zero degrees advance/retard.

michialj

yeah, as far as i know. it only misses on one, some times 2 cylinders. the self diagnostic test throws codes for just the one cylinder normally and the right O2 sensor, which i am about to replace both of those.