Misfires/ stalling issues, new plugs,wires, cap,rotor, etc. Options

[batcavee00]

Sup guys, I just rebuilt my block, but I can't get it to run right....it starts n runs, but runs nasty n it stalls.i changed plugs, wires,cap, rotor, fuel filter, etc. with no luck.....i got a 94 gt manual trans. Plugs are gapped to .044. I dont think it's an injector issue, im running the stock ones. I also tried running some rx7 ones,but it still misfires. If I let the gas pedal go it stalls. Messing with the timing doesnt help eirher.I tried looking for vaccum leaks by spraying starting fluid around the intake n manifold areas, but the car runs the same...any ideas what it could be?

[vile_v]

Just a guess but it does sound like you have fuel pump issue? give that a try.

[stephen_lee]

is the valve timing set properly?

[batcavee00]

I think so, I had the crank set on the zero mark, and intake cam right in the hole. The exhaust cam was aligned with the dots on the intake gear...i think that sounds about right

[stephen_lee]

if you have a timing light use that to check you are at 10* BTDC

make sure to bridge E1 and TE1




on a side note the only time i set timing like that is with the engine out of the car.

when its in the car i use that method to get close but im usually off, so i start it up, revv to redline.

if its smooth all the way to redline, u got it right.

if it struggles at low rpm but zipps up quickly once you get into higher rpms, or
if it revv fine at low rpm but stalls and wont go to a higher rpm (usually 4000) and feels like a soft revv limit (imagine going uphill in 5th but u cant accelerate anymore due to too much load, even tho ur WOT)

i move the timimng one tooth forward and try again. if its worse, move it 2 teeth back

HINT: if your valve timing is off, it will be difficult, if not impossible, to set your ignition timing properly... plus its pretty pointless lol

[batcavee00]

Mine revs kind of ok, but it stallsat iddle. If I rev to the max it will sputter like crazy n stay about 4500rpm.

Now what teeth are you talking about when you say you move it one or two back?how do you do that?

[stephen_lee]

move the timing gear 1 tooth on the belt.

but it doesnt sound like thats your issue.

is your CEL on with the engine running?

[batcavee00]

No cel....should I give it try still on the tooth thing, or do you think it may be something else?

[stephen_lee]

you can try on the timing. cant hurt.

[batcavee00]

I did a compression test just for the heck of it. I got 190psi even on all 4. Ill try the tooth thing tomorrow n will report back. Thanks for all the help so far!

[Neon90424]

bad afm/map sensor?

[marco-polo]

move the timing gear 1 tooth on the belt

Which belt you speak of?
since i have same issue.

[stephen_lee]

timing belt.

but as i said it sounds like something different... like a map issue

[199celica]

alright bud this one to me sounds like an IAC (idle air control valve) problem every now and then carbon build up will get all gunky and nasty inside of it so you have two choices buy a new one or take it off and clean it its under the throttle body which can be a pain but can save a bit of money yeah buddy thats how we like to do save money and spend it on our ladies (6gc)

[batcavee00]

Lol yup thats true, these days we gotta save $$$....ive been bysy all week, finally tomorrow ill have time to clean the iacv. If that dont work ill try a different map sensor,followed by the timing belt thing. Thanks to all for everything so far!

[6G96GT]

This sounds exactly like my issue and I couldn't trace it either even after full tune up and properly gapped plugs. Also my engine was fully rebuilt 10K ago. Here's what solved my problem and it's kinda hard to believe it was the culprit.

That sensor in the pics (the one with the green wire sticking out of the top) sh*t the bed and caused my car to misfire, not start, backfire, and run like crap when it did run. Not saying this is your problem but it's worth looking into. The sensor only cost $40 too.




This post has been edited by 6G96GT: Aug 20, 2011 - 8:21 AM

[stephen_lee]

coolant temperature sensor.

[Delta_Phoenix]

I'm having a similar problem with my 94 ST. Died last night while riding around and wouldn't start. Tested ignition coil resistance and it was out of spec. New distributor+coil+ICM+plugs are in and the car runs, but will NOT idle smooth. It revs like a champ, but misses when maintaining any RPM. Checking plug wire resistances and ignition timing tomorrow. Don't really understand how the ignition timing could be off, as the distributor in the 7AFE only goes in one way along with the ignition rotor. Unbolted distributor and turned it as far as it would go in both directions with no luck. I even tried turning the distributor lug that mates to the cam 180 deg. It will NOT go back in like that. I'll see what happens tomorrow and report back.

Also, how would the coolant temp sensor cause those symptoms? Never heard of that one.

This post has been edited by Delta_Phoenix: Aug 20, 2011 - 8:33 PM

[6G96GT]

coolant temperature sensor.

Yep, that's it. Doesn't make sense but after it was replaced, my car runs like a dream again.

[Delta_Phoenix]

Replaced cap, ignition rotor, and wires. Still misses when idling and cruising, and pulls hard and smooth at WOT. Timing check incoming...