idle and decelleration issues.

[Sidewayzzz]

Alright, this KA is starting to piss me off (and I am an avid sr hater...).

Don't remeber exactly when it started but i'm having some weird issues on decelerattion and my idle is ****ing erratic at best. The idle will be anywhere between 700-1100...it doesn't shift extremely fast between idle, its hardly noticable most of the time, but you can hear the motor change pitches while idling. I will just stop at a light and sometimes it will idle at 750 .. sometimes 900 .. most of the time 1000. This isn't a "searching" "hunting" type idle...it will usually come to 750, then rise to 1000 and you can hear it change pitches in the exhaust... and if you stare at the RPM's and watch very closely it will shift about 100 rpm's up and down. It's very hard to notice, but I think this is important with my decelleration problem so I want to note it.

On decelerattion my car will fall extremely fast to very low rpm's .. i'm talking 300-400-500 ... and it will come back up to 750 when I come to a complete stop then rise to 1000. It feels like an atmospheric blow off on a maf based turbo car almost. If I pull the car out of gear while moving the rpm's will fall to extremely low levels .. IE 500-600.. Very rarely, the car can die if I pull it out of gear to stop, or even coast. When I come to a stop it usually falls extremely low to the point it should nearly die, then the IACV brings it up to 750...then 1000. If i pull it out of gear while coasting, it usually falls to 500ish and stays there, until I come to a complete stop, then it rises to 750...then 1000.

Today I .. uh .. took an IACV from the junkyard and cleaned it up .. swapped it .. same problem exists.

I can have checked the ECU for codes and on a few occassions it did show code 33, which is the o2 sensor circuit.

I have 3 different o2's that I have swapped and tried, they are working fine, I just had to replace my o2 actually. I've tested the o2 via the ecu test, it's working as it should. Harness/Connector falls into the aforementioned state, if the harness/connector was bad, the o2 would not give a correct resule and that would be noticable in the o2 test.

I'm on my last straw with this motor ... any help is appreciated guys, thanks in advance.

[Acecool]

Check the O-Rings on the injectors and the fuel pressure regulator thing right near the fuel rail (with like 3 or so rubber hoses coming from it)

That is what caused all of my problems with idle, hesitation and stutter.

[Sidewayzzz]

Could you elaborate a little? How do you check, what am I looking for? Which O-Rings ... the little ones on the injectors or the larger ones that go onto the head? What am I looking for on the fuel pressure regulator? I have replaced that within the last 3-5 months tho.

I'd like to check my fuel pressure, but I have no shrouter valve...i'd have to find a fuel pressure gauge .. a cheap one too, and cut a fuel line in half and put it in there ... etc ..

Any additional info would help.

[vancouverbc]

Make sure the hose from aiv to filter housing is disconnected. You could check to see if aac is getting voltage. A weak battery or alternator could cause high idle at stops.

Your ficd might have a bad ground . Im not sure why deceleration is connected to ficd.

[vancouverbc]

Could you elaborate a little? How do you check, what am I looking for? Which O-Rings ... the little ones on the injectors or the larger ones that go onto the head? What am I looking for on the fuel pressure regulator? I have replaced that within the last 3-5 months tho.

I'd like to check my fuel pressure, but I have no shrouter valve...i'd have to find a fuel pressure gauge .. a cheap one too, and cut a fuel line in half and put it in there ... etc ..

Any additional info would help.

It would be the little o-rings. they get damaged unless you lubricate. people manage to damage them a lot. fuel pressure gauges are cheap but i had hard time tapping in because connection kept failing and spraying gas.

[Sidewayzzz]

The AIV / PAIRC ... whatever you want to call that, is gone. I only have the EGR system now, i've gotten rid of the vacuum canister/dillution thing.

Now as far as the AAC, the auxilary air control valve right, that is only on when you have AC/other systems on that put a strain on your motor ... Im not running those systems when I have the problem ... haven't even tried turning them on actually.

FICD? Not sure what that is ... could you tell me? I can have auto**** test my battery/alternator tomorrow, but I don't think thats it...

[Acecool]

Take a picture of your engine bay and I will circle what you need to check.

[vancouverbc]

The AIV / PAIRC ... whatever you want to call that, is gone. I only have the EGR system now, i've gotten rid of the vacuum canister/dillution thing.

Now as far as the AAC, the auxilary air control valve right, that is only on when you have AC/other systems on that put a strain on your motor ... Im not running those systems when I have the problem ... haven't even tried turning them on actually.

FICD? Not sure what that is ... could you tell me? I can have auto**** test my battery/alternator tomorrow, but I don't think thats it...

The AAC via the computer is the main thing that controls idle. (auxilary gives the wrong impression of what this valve does)The computer takes information from all the sensors and opens and closes aac accordingly. The FICD comes on for air conditioning, for sure, but Im not sure if it comes on any other time. A trouble shootin guide implied the ficd supplies air during deceleration.

[Sidewayzzz]

Well today was a busy day, I took off the throttle body to set the adjustment screws for the idle and wot. I set the idle adjustment screw so that when i snapped it open/close it didn't click (the way the FSM describes to do it). I figured while I had it out I should set the TPS to the correct spec, so i set it to .45 closed throttle and rotated the set screw on the TB for WOT so that it was all the way out, and my TPS only goes to 4 volts and change WOT...I believe it should be 5, but thats not really important.

I checked the timing, it was 15 degrees BTDC which is 5 off, so I set it to 20 degrees, which is stock.

Bypassed the coolant lines, I don't need those. I also plugged the 4 vacuum lines I had previously when I had the AIV and Vacuum Canister (they were previously plugged at the end of the hoses, this time I did it right from the hard lines).

I want to make it known that I have replaced FPR, TPS, o2 Sensor, MAF, ECU, and the Plugs all within maybe 5-6 months. That's not to say they are not bad, but I have done more than a few things under the hood and this problem is just .. weird and unusual.

SO after all that mess, It doesn't try to die coming to a stop anymore, it doesn't go much lower then 600 rpms (and thats only sometimes...) when I pull it out of gear. What it does do thats strange is it idles at 1000, but if I pull it out of gear or press the clutch in while coming to a stop, BEFORE I come to a complete stop, it will idle at 750 and while i'm coming to a stop it rises and by the time I stop its at 1000.

To be more specific, I was on the 95 and doing about 65-75 and pulled out of gear ... rock solid at 750 for a good few seconds. When I came home, I flipped a u-turn to park and when I took it out of 2nd to come to a stop, it went to 750 and while I was braking it came up to 1000 by the time I came to a stop.

[Sidewayzzz]

bump...anyone got an idea?

[vancouverbc]

1000rpm is bad for an older car. the battery/alternator might be weak or the car is working harder to stay cold when you are stationary. (this is speculation)

vacuum leaks would cause high idle. or your idle might be set too high.