86White_T/A305

Ok guys here is my issue with my setup.i recently did an engine swap to a 350 with a 79 block with tpi speed density.it has no emissions equipment on it.my cam isnt anything crazy just a bump up or two from factory.i can get cam specs later if that helps,24lbs ford injectors,heated 02 sensor,corvette l98 heads,march pulleys,hooker 2055 headers,magnaflow 93 lt1 catback.rebuilt 700r4 and a 2500 stall converter.

Now the car here is what i noticed.when the motor is cold it take a bit of crankin to get started or if i floor it when cold it starts up about 1 sec of crank time.after its warm its about half a second to start or less.whenn its running it hunts a lil between 800-1000 rpm but not all the time.then starts to really hunt and go anywhere from 650 to 1200 to stay running.if i pump my brakes the car wont stall.if i put it into gear and sit there long enough it will stall unless i gas her a lil.

tests i have tried so far was inejctors,they were new but using a noid light proved them workin perfectly,checked vacuum leaks and none was present.ive adjusted the tps and iac as describe here on the tech articles.im not getting any codes,ive checked plugs,wires,cap,rotor,pickup coil,installed all new sensors except for iac itself.cleaned the throttle body with intake cleaner spray from gm while it was running and blippin the throttle.havent checked fuel pressure since im lackin a guage to test that.fuel pump primes when i turn the key and the car doesnt sound like she is starving for fuel up top at wot.i manage to get my hands on a tech 1 scanner from gm and my readings seem to be accurate for temp,o2 readings seem fine and workin,spark advance is aound 7-8 degrees on the scanner.cars goes into closed loop.ive notice that on the scanner it says the ecm wants to idle at exactly 737rpm but whenever its starts getting close to 800 it wants to die.scanner says my leanred iac count is 40..not sure what that is suppose to be set at.

when the car is moving..everything is golden,no stumble,hesitation,backfire at wot and im happy but i pray to the heavens when its time to stop and sit anywhere.its embarassing when it stalls and i gotta lightly blip just to keep at a light.please any other things that you guys know that can put me closer to solving this would be much appreciated.most other threads i read were for maf tpi and dont apply to me from what i understand.im using a 730ecm,all new harness from tpiparts.com.thanks for any insight.

Lucid

iTrader: (4)

I was looking at the pics of your engine and noticed that you have holes in your valve covers, do you have the PCV system hooked up? You might want to get a couple of breathers and plug up the other holes if you are running the stock PCV system.

86White_T/A305

Yes i do have the pcv hooked up and a breather.the pics in this thread are older from during the swap.

typhoon

Do you have the VSS hooked up? That can cause your stalling problem when coming to a stop.

86White_T/A305

yes i have vss hooked up and working properly.my park/neutral wire is hooked up and working aswell.yesterday i gave a shot at taking my tb off and spraying it with intake cleaner and wiping it clean.this helped at first but now the car idles at 1200 and if i adjust it down she stalls again?but it doesnt hunt as much

ryn28

iTrader: (1)

I had a similar problem but again, mine is a maf setup, 165ecm. Regardless, you don't mention anything about the chip. When I first had mine done "they" forgot to turn off the EGR b/c I have no emissions also but I was getting intermittent codes which you say you aren't. I also had to plug a port on the side of the throttle body, above the iac I believe it was. After I burned my own chip and turned off the egr the car stopped stalling and idled properly.

86White_T/A305

yes the chip as far as i know has no egr or any other emissions on it.i do have the port you mention above the iac plugged aswell.im wondering if taking the car for a drive would help smooth this out.does the 730ecm need a learning time for everything to block learn?..would taking it on a cruise on the highway help b/c thats the only thing i havent done yet is drive it around.i think i may just replace the iac but im not exactly sure the procedure of removing and installing one and setting it back up.im thinking maybe im not making enough vacuum and ill go record what im gettin from the scanner and you guys can tell me if thats causing this aswell.thanks for the replies guys.im sure im getting close.

86White_T/A305

well i got the car running and here are my results from the tech 1 scan tool and a fuel pressure guage readings.

when i turn the key to the on position and hear the pump prime the pressure barely even reads 1psi :S.then after about 3 seconds of cranking and it starts it reads about 10-15psi.i notice a very small leak on the fuel line on the frame going to the fuel rail but i can fix that easy...also when i turn the car off it doesnt hold pressure at all and drops right to zero.when the car is running i am getting 13.6 volts to the pump.

next is my map sensor readings are around 40-45kpa at 1.6 -1.9 volts at idle.what do you tpi gurus think this is leading me to with my stalling and erract idle problem...fuel pump or fuel pressure regulator.i took the regulator apart and it had no tears and seemed in good shape.need advice

Ughh61

for one thing i know you need around 40psi
so i dont think you have the right fuel pump

mnorton

I had stalling problems that were caused by low fuel pressure. If you have a Holley AFPR, that would be the likely problem. They are crap.

86White_T/A305

no i dont have a afpr yet,its one of the next mods on the list.so basically i think i was given a fuel pump for a tbi and not tpi great..i bought that a year ago used from a camaro/firebird recyclers shop.i also noticed as it sits right now if i put her in gear and sit there i have to have the idle adjusted to around 850-900rpm so she wont stall..but when i do that it idles around 1100-1200 in park.is this normal for modded 350tpi's?