sn95_331_GT_ yellow

ok, so here's the analysis, as good as i can describe it. i know its almost impossible to diagnose a car without being there, but any help is better than none. when i first start may car, it sometimes starts up, idles for a few seconds, then almost dies and goes into a really fast idle ~1600rpm. other times it starts up and doesnt do this. when it does do this, my CEL flashes on and off for a few seconds. after a minute or so, it goes back into its normal idle settings. doesnt matter if the car is cold or hotthe second problem is when im just cruising around my CEL will come on and off at even intervals (about 2 mins on, 2 mins off). also, when using more throttle, usually more than 1/2 or so, it falls on its face then picks up like hitting nitrous. it feels like going from Open Loop to Closed Loop due to the heavier throttle applications. the only things i can think of are either it is my computer has gone to Hell in a hand basket, or my IAC motor. i want to get this figured out, its making my car not fun to drive, and im worred about doing possible damage. one more thing, when it has been sitting for a while, i have to cycle the key on and off several times to get pressure in my fuel rails ( i can hear the pitch of the pump change). is that just the stock pump being crappy, or yet more problems? thanks guys!

mjr46

do you even know what open loop vs closed loop operation is??? cause your correlation for lack of power to it is ..ummmmm lets say not applicable...anyway..if cel is on ..run a koeo/koer test and see what probs the ecm sees via the codes it gives you..which will indiacate a prob in a system of the car....from there you can narrow it down

sn95_331_GT_ yellow

just to make sure, CL is when you're just crusing around, and the ECU will make changes based on load, rpm, info from the O2 sensors (which is why they cycle from lean to rich, in addition to cooling the cats), and OL is for startup, and WOT, right? i may be way off here, but i think thats how it goes. anyways, i ran both tests, and the only code i got was for cyl 8, for which i already know has a compression leak (stock valvesprings FTL...). ill try it again tomorrow when i get home from school and work, but so far, this is the 2nd time Ive ran the tests in about a week and neither time has shown anything[:@]. im about ready to sell my bike to get the 351 in there STAT... oh, btw i bumped my timing to 13* (SPOUT sensor out while adjusting, then plugged back in when done) if that makes any difference or helps.

mjr46

closed loop operation is when vehicle reaches a specified operating temp and the ecm begins to interpret sensor inputs and send output commands for fuel and spark timing based on readings interpreted from input sensors......in open loop the ecm carries out control based on a prestored set of parameters in the Ecm.....open loop is also used at WOT............AS FOR CYLINDER 8 you need to fix that prob which may be the whole issue at hand

sn95_331_GT_ yellow

not to sound like a complete idiot, but its been like that since the day i bought it (cyl 8). i dont think it would all of a sudden make that big of a difference. i checked the compression again the other day, and all the cylinders were identical to where they were about a month after i picked it up. it almost sounds like a vacuum problem still. basically, if the IAC motor was at fault, could it cause these kinds of problems? i think that might be it, but i want to make sure before i spend $110 on a new one. im not doubting that cyl 8 isnt helping the situation, but i just want to get it running good enought that i can enjoy it this summer before i do the 351W swap over the winter. thanks for your input still.

lxman1

Try removing the IAC and cleaning it with brake parts cleaner to see if maybe it is just carboned up and sticking.

AdderMk2

idiot

lxman1

Who are you calling an idiot?????
The IACcould very well be one part of the idle problem!!

Thanks for your useful input, though.

AdderMk2

im calling the OP an idiot b/c he knows there is a problem with his engine, and continues to beat on it and ignore the problem

sn95_331_GT_ yellow

i wasnt aware that driving it back and forth to work and college every day constituted beating my car, but oh well. i know damn well there is a problem with my car, but so far, it continues to run pretty well close to 100%, and unless someone wants to donate funds, its the only car i have to drive since my brother crashed my beater. im not trying to start a pissing contest here, just asking for advice and seeing if someone has experienced similar problems. i have two blocks sitting in my basement, and am picking up another, and if it werent for the nickel and dime **** like this, one of them would have been in there LAST year.
im not going out and driving it like a ricer, i almost always baby it. and now that this problem has surfaced, barely have the heart to drive it because i dont want to hurt her. so before you go accusing me of treating something i worked WAY too hard to attain like ****, consider for a moment that i actually want to be able to one day claim my car as an antique. i put in way too many hours of blood sweat and tears both getting and maintaining my car to do things like that.
thanks to everyone for their ideas though, im still trying to sort this out, maybe ill catch a lucky break somewhere. i should have mentioned that cleaning the IAC motor out was one of the first things i tried, and had no effect. next time ill post EVERYTHING so i dont get accused of being a dumb****.