Alright, so today i went out to start my car and it wouldnt start right away, it is a obd1 b16 in a obd2 car and its been this way for awhile with no problem, but after turning it over and it backfiring once, and making a weird suction noise from the intake it finally started with a very rough idle, and now jumps from 1000-1500 rpms, i let it idle for 20 minutes to see if it would help it seemed ok so i tried to go around the block, but it bogged down and wouldnt move, so the whole process started over, i really have no clue what it could be. please help me here. it has new plugs and wires also...


<U>UPDATE:</U>
ok update, i changed the o2 thinking it was running out lean becuase of it, turns out that isnt it, but i also have a new iat sensor comming friday. map and tps turned to be ok. so my question is, since this is only happening in closed loop, what other systems are running in the closed loop cycle to measure load? everything i can think of would be acting up upon startup ie, fuel filter, fuel pump.. could it be the fuel regulator? does that measure differently in the loop? please let me know of any ideas..



Modified by upstate at 7:52 PM 11/25/2004

 

From your description it sounds like a vacuum leak at the throttle body, but those dont generally create enough problems to make the car stall. Ill help you out more later when i get off work. Spray some carb cleaner around the intake manifold and see if that changes your idle for now...

 

it sounds like you arent getting enough gas. fuel lines or fuel pump would be my first guess. im going to have to do a lil more research to see what else it could be

 

hey thanks for any help i get also, i pulled the ecu, the only markings i found were p30 skunk2 if that helps.

p.s. i sprayed carb cleaner it seemed to raise my rough idle from like 750-1000rpms to 1000-1500rpms, so that was nice but still didnt do much, ill have to wait till tommorow to check the hoses.

 

spraying carb cleaner isnt designed to raise your idle to make it better. Its to detect if theres a vacuum leak. You didnt spray it directly INTO the butterfly valve in the throttle body did you?

 

oh, and a rough idle and sputtering is almost always ignition. It could be a fuel issue, but thats harder to detect if you dont have a fuel pressure guage.

 

no, i took off the throttle body thinking it was gunked up and sprayed it out... than it raised it, so i guess it was gunked up somewhat..

 

No, you need to spray around the tb and intake mani while the car is running, if you hit a spot and the idle jumps, youve found a leak...

 

bump pleasaee

 

update: i had my friend look at the car today, it started up fine and we drove it to my job, the stoplight before as he was pulling away, it bogged down and started the same symptoms.

so, this problem only occurs at normal temp, and it is not running rich, (pulled the plugs look fine and smell fine so there is ignition) its almost like its not registering the load as the throttle increases like its leaning out, so is this the map sensor?? thanks again for any help

 

Once the car warms up, it starts reading off your o2 and going into closed loop mode, it could be a problem with the o2 sensor. If you have a skunk2 'chipped' ECU, im betting its disabling the error code for the o2, which would be 1 or 41 depending on whats exactly wrong. I would test the o2 itself for voltage, i cant remember the exact specs on what it should be but im sure you can find them on here somewhere.

 

right, thats what we thought, but, why would it be causing a lean out situation? wouldnt that be the map? is the map used in the closed loop? im not saying it couldnt be the o2, ill check that out as well..

 

Whats happening is that the ECU is dumping alot of fuel during cold startup and thats fine, engines like that. Once the car is up to operating temp however, it should be leaned out. The o2 is probably not reading properly and still dumping lots of fuel, causing you to bog and stall. I dont know if the MAP is used during initial startup, but im almost positive it is, as to guage the density of the incoming intake air charge.

 

alright, ill test out the volatge, how exactly do i do this and what should it be?

 

i told you, im not sure, try searching for it.

 

ok, is there any way to test the map sensor? or is that just use a known good one and see the difference?

 

you have a few options....


1) buy a multimeter and a helms manual.

2) buy a multimeter and use the search feature.

3) get a known working MAP and plug it in.

 

ive already used search, but i cant seem to find any instructions on how to test them...

but i found an online helms manual and got them, thanks for your help... i do appreciate it.


Modified by upstate at 8:08 PM 11/23/2004

 

No problem thats what this board is for. See, if i didnt tell you go looking, youd have one less helms in .pdf format now wouldnt you?

 

ok update, i changed the o2 thinking it was running out lean becuase of it, turns out that isnt it, but i also have a new iat sensor comming friday. map and tps turned to be ok. so my question is, since this is only happening in closed loop, what other systems are running in the closed loop cycle to measure load? everything i can think of would be acting up upon startup ie, fuel filter, fuel pump.. could it be the fuel regulator? does that measure differently in the loop? please let me know of any ideas..

 

No, and its not your IAT either. ive run without one and the car doesnt die. Ill look into this deeper tonite and ill let u know..

 

thanks i appreciate it.

 

any info on this?

 

bump

 

patience, young padawan...

people are still relaxing from/for thanksgiving...