hi guys, i am marot from the netherlands, i have a 3.4 engine ,if i start than its not working well in the first 3 minutes ,(open loop) when my temp meter starts moving its working ok, i think tan its in closed loop , why its stumbling ,not well accelering ,holding back etc. in the open loop, will a heated o2 sensor help this problem, while its going sooner in closed loop,
Hi and welcome to the forum. Is this a recent engine swap, or has it been running well for a while then went bad? Has it been sitting for a while and you got it out to run? Did you do any tune up adjustments? Do you have any codes set?
hi guys thanks for reply, i bought it with this swap and replaced all sensors with new one, i have no egr,no canister, no airco,no cruisecontrol. no leaks too. its stumbles till its in closed loop, than its driving ok , its still idle hunting when warm but that only annoying will a heated 02 sensor help when its sooner in closed loop
Base timing of 10* with the A&B pins jumpered on the ALDL port is correct. The car MUST be in diagnostic mode to set timing (A&B jumpered).
Your issue could be the fuel injectors. Especially the hunting idle. Are you using the 15lbs stock Fiero injectors or the 17lbs injectors from the 3.4L engine? I suspect you have the 17lbs injectors with the hunting idle issue. When the car first starts does the exhaust smell rich? Does the exhaust look black? Have you pulled a spark plug and looked at it's color?
yes thats my problem it runs terrible till he go in closed loop ,may be i have still 15 lbs on it , if so will 17 lbs run good till he went in to closed looped, so i dont have to wait each morning after start till he went in closed looped, thats waiting till the water temp is rising , than it rides better, (water temp rising means he is going in to closed looped) before its runs terrible ,stumbling, not responding well on the stoplights ,accellaration is not smooth, untill few minutes later when i see the watertemp is rising on the tempgauge than it start to run ok
so i have read some post and i will describe it from the start , when i first start the engine in the morning, its starts immediatly, and idling 2500 for a while than its stalling to 1000 rpm or so, than its hunting idle like 1300 than back to 1000 and so on, than i drive the car and its stumbling and holding back etc. till my water temp is rising (closed loop) and from now the car is drivable , if i stop at the lights than its starts hunting idle usaely when my fan is kicking in , could i have a fuel pressure issue? maybe is my fuelpomp not ok? and somethimes its stumbles when i driving the car for a while too ,not always