Rough uneven idle

[Manboy4870]

That's what I thought but I've sprayed to check all the pipes and hoses and no change lol however since I agjusted the tps the vac has gone to 20 don't know why it's very strange it's running a bit better now not perfect but as good a it's been in a while

 

[khubner1]

20 that seems like alot of vac mine only gets as low as 12

 

[EVOCPE]

20 vac sounds about right, i get around that also, maybe even 22 vac

 

[Manboy4870]

From what I've read it should be anywhere from 16 to 20

 

[evo-gsr]

Both my cars sit on 20 vac @ idle ....(GSR with 63t and the Evo)

 

[4piknup]

since I agjusted the tps the vac has gone to 20 don't know why it's very strange

As milkandoj said, it's important that the ecu knows when it's meant to be idling. If you don't have the separate switch as the throttle stop, then it's built into the tps.
Even with those guides, the tps will be wrong, it's fairly close tho. I set mine once I got my ecmlink in. Also you will need ecmlink or something to set the biss. There is no way to get this correct without knowing the isc position.
Biss really needs to be set as if not the isc can be topped or bottomed out and this can cause the coils to overheat and the isc to be ruined.

 

[evo-gsr]

You can also use a palm logger to help set/adjust what jack of all is on about...

 

[Manboy4870]

Ah ok so if I was to take it to a place with a palm logger they can fine tune all the idle settings?

 

[oggy]

yeah, under normal running conditions, I've never been in a car that had less than 20ish vaccuum at idle - unless they had cams. But by the sound of it you've already checked it so thats good to know!

where abouts is this throttle closed switch?

 

[4piknup]

On the throttle body. It's either the throttle stop is a adjustable switch. I think this is 6 bolt vr4, and sonata. Or it is built into the tps on evo and Gsr. I'm not sure how it works on the evos, if it is on the 4th pin on tps or if the ecu interprets a position on the tps as throttle shut.
I can feel the switch working in mine when driving around. When decelerating with your foot off the throttle, the ecu turns injectors off to save fuel, (till revs drop to around 1200 rpm then switches them back on) but if you touch your foot on throttle, there is a slight jolt and the exhaust note changes as injectors turn back on. This is another job of the throttle closed switch

 

[evo-gsr]

Ah ok so if I was to take it to a place with a palm logger they can fine tune all the idle settings?

If you have the correct ecu and correct obd plug/port then the palm logger should "talk" to your ecu.
From memory you need a pre 1994 obd plug/port and an ecu with the part number ending in the numbers 040

 

[4piknup]

I only had a obd2 plug in the ute, I had to wire in a obd1 (3wires). Dunno about ecu numbers at all.

 

[4piknup]

lalso sounds like a hard start like a low battery but that's new too. Any ideas????

Better put a timing light on it as well, this may be caused by advanced timing.
Or just retard it a bit and see if it better, just mark where it is now to return to where it is.
Really should check that the timing mark hasn't moved as well, this seems to be happening a bit as they are getting old, and once you have found if you have true tdc, just check your cams are where they should be too. I think you are pretty close as you have good vacuum, just a couple of fine tuning to get it good

 

[khubner1]

yeah my timing mark on the balancer has moved a god 1/4 turn from where it should be. (harmonic balancer is on the shopping list for the next trip!)

 

[Manboy4870]

It's sounds like the timing is off but the mark hasn't moved at all still getting a little stutter when I start it when it's cold

 

[EVOCPE]

Whats the timing set on?? also you remember to earth out the timing plug when you adjust the timing?

 

[Manboy4870]

It vibrates the car pretty erratically at idle and there is a kinda flat spot in the throttle just off closed position, when you hold it at that spot the revs jump from 1400 to 800 as long as you hold that spot really weird, possibly the harmonic balancer ??

 

[EVOCPE]

That really sounds like the TPS

 

[Manboy4870]

Ive swapped the sensors over coz I have a spare but if it is it would have to be where it's set, I set it at .6v

 

[clone]

my timing is advanced further then the bolt whole limits.. thinking this might be causeing my idle problem