Irradic idle, any help appreciated

[Feivel]

Any suggestions are appreciated.

Irratic Idle.

code 16, 25and 29. KL-ZE straight neck battery relocated in trunk.(bad ground?)
running 1.8cpu (have 2) 1.8 distributor (have 2) fuel pressure regulator, the vacuum thingy (switched ZE for a 1.8 to see difference,touch smaller in size, none made) MAF was checked with spare.
On start up, idle rockets to 4000, after 5 seconds it drops to 1000 and bounces through 1500 ONLY WHEN TP SENSOR IS AT COMPLETE RIGHT if not it revs at 4000 up to 5000!!!
When driving, in gear coasting tp cuts and car jerks, then comes back. have to clutch and gas a hell of a lot to make ride smooth! very annoying problem any suggestions apprecited

Thanks again for your time

[Feivel]

bump

[WhiteFinish]

EGR codes aren't that bad. Maybe you could fool it someway but I don't have it either (search it)

Try to tune your engine

First check all vacuum with the vacuum diagram
Set fpr without a vacuum source hooked up to 35-38 psi at idle
Set your timing in diag mode
Set your idle in diag mode
Set your tps
Check your sparkplugs (correct gapping)

[msd-super]

Sorry but what is FPR????

I got the Jerking problem with my ZE as well.... Are u running a k8 tps???
Cuz I herd that it sould be ur stock K8 TPS...

[umcamara]

FPR = Fuel Pressure Regulator

[Feivel]

I see my post didnt go through yesterday .... it was a good one too .... o well,

after all that is said and done what do you check next? like i said i got two of just about everything and nothing changes. my next thoughts were O2 sensors or IAC (thing under the intake with the bigger vacuum lines)

i am running a kl-ze straight neck with the stock ZE throttle body and tps. i had no problems until i parked it for the summer .... yeah thats right i parked it in the summer ?!?!?!?!? i had a work truck and a couple problems with the car and was just too lazy. now i got it all up to par except for this problem. maybee the IAC thing got jammed??? (since im running straight neck it touches the brake booster and made itself a groove. theres no way i got the TB off to check it unless i lift the engine or remove the brake booster !!!)

any suggestions ???

hard on gas, revs to 4000 unless tp is completely to the right then it bounces from 1000-1500. in gear it jerks (because of misadjusted tp sensor)
IAC?
O2?
How do you check the FPR isnt it that doo hicky with the vacuum hose attached to one side of the fuel rail? i added the solenoid to the circuit, not needed but maybe it will clear the code.
EGR is not a problem since i am running the 1.8 ECU. ZE do not have a EGR hence no code with the(correct me if im wrong) kl31(ZE) ecu wich is 400$(or 100 chipped 1.8 in MTL)

[Feivel]

im going to try to change the idle air control valve under the throttle body. since i have a straight neck and the master cylinder is in the way im going to have to disconnect it from the booster. big job for a little hope anyways ill let you know after

[davmac]

Feivel even if the throttle body is jammed against the brake booster you can still remove it without messing the brake booster or pulling the engine. Put 2 nuts on the throttle body mounting studs (top 2) and turn the inside nut until it jams against the outside nut. You should then be able to use the inside nut to remove the stud. You should probably replace the studs with appropriate length bolts given the tight work space.

Very unlikey O2 sensor is at fault. It could be the IAC but check the following:
- Air in coolant
- Intake air tube leaking
- Vacuum leak

No adjustments to the IAC so a new one might do the trick.
There is only one viable positon for the TPS and you should find it using a feeler gauge and measuring continuity - it is easy to do this with the throttle body on a bench:
Connect ohmeter to 2 bottom pins (BR and BK/DB) and you should get continuity. If not, loosen 2 TPS retaining bolts and rotate until continuity has just barely been achieved. Semi tighten 2 TPS bolts.
Insert .15mm (0.006”) feeler gauge between the throttle stop screw and throttle lever. This should not break the continuity. Rotate until you barely have continuity with the feeler gauge inserted.
Then using a .50mm (0.020”) gauge inserted verify that you no longer have continuity.
Tighten down TPS retaining bolts.

[Feivel]

LONG STORY SHORT, i think its the IAC. just bickering underneath
DAVMAC - thanks for the input but im just gona put the TP about where it was when i finally find the problem. and thanks for the tip i had forgotten i could do that

Ive had 3 people look at it and 2 of them being old school type or junkyard mechanics, there usually the best at finding stuff like vacuum leaks and such, they live and breathe the stuff ya know what i mean. both said there was no vacuum leak you would hear it and the other suggested the IAC (wich was the next step i was taking) so i think it is that. this problem has been for about a month and has gotten worse. starting off at 2500 with the tp at the right spot to 4000 then i moved the tp and got the bounce but it was reving at 900-1500 and only revving 4000 at start-up, now today it starts up and auto revs to 4000-4500(warm) or about 3800 (first start in am) then drops and bounces after 5 seconds. super annoying in traffic because the ECU doesnt see the tp reading until it hits a certain point and then it kicks then stalls out for a sec and jumps back on. looks like i just started to drive stick and ill burn my clutch in no time with sunday drivers and school zones. ...ooo00OOO All i want is a good running ZE OOO00ooo...
ill get back on the fix after

[davmac]

Good luck. I know how annoying the bouncing or surging idle can be. It makes driving super annoying and can even be somewhat dangerous. Once warm my KLDE would surge at idle due to air in the coolant from a coolant leak. The coolant temp sensor was throwing a goofy signal to the ECU since it was not always submerged in coolant. Long story short - my leak was from head gaskets All seems better now - many hours and $ later.

[Feivel]

UPDATE!!

So i got the TB off (thanks davmac for the brain fart) and used about 3 caps of varsol, let it sit for about an hour shook it around and swooshed my finger to try and clen the part and the rusted spring stared to move. i threw it all together and started the car (placing the tp back at approximate spot and re-installing the ZE FPR, i used the vaccuum solenoid for the FPR and just plugged the wires back into itself maybee it will clear the code (25 i think) its apparently not needed on the ZE straight vacuum source to the FPR (maybee i can "T" into the vacuum circuit here for my CRUISE CONTROL!!!!! that would be nice anyone can answer???)

It still revs at 3000 (wich is pretty resonable considering) now could one of those springs still be seased and that be the cause of this? or need i search more? what Throttle Body could i use that is the same size and all of the ZE (i noticed the bolt pattern and size difference in valves and such between the two. 1.8 and ZE (is it the millenia edition 626???)

Thanks again for your time
MSD super you should try cleaning you IAC (underneath the throttle body, there are two hoses connected and a circular valve, it's 4 star screws (and a 12 for TB) a bit of varsol and an hour waiting time. might help you a lot (or just get a new one from the wrckers)

Got to get my daughter, ciao for now

[Feivel]

well. it seems to have made an effect but is still back at square one, i think i should exchange the part all together.

what car do i get a new one

[Feivel]

so i was sitting at a light for 15 seconds about (usually i turn it off but i just let it this time) and it was revving at about 4500. i press the gas change gear and poof all of a sudden it's dropping back to 2500 wich is music to my ears. regardless i would like to completely exchange the part, wich vehicle do i get one from that will fit? (prefferably just the IAC(4 star screws underneath TB) i would like to keep my 2.5 ZE throttle body
thanks again for your time

[WhiteFinish]

EGR codes aren't that bad. Maybe you could fool it someway but I don't have it either (search it)

Try to tune your engine

First check all vacuum with the vacuum diagram
Set fpr without a vacuum source hooked up to 35-38 psi at idle
Set your timing in diag mode
Set your idle in diag mode
Set your tps
Check your sparkplugs (correct gapping)

Have you tried these things?

[wytbishop]

I can't recall which IAC's are interchangeable etc. but there is a TB/IAC comparison write up on MX-6.com I believe.

I also use a straight neck ZE. I modified both the throttle linkage and the brake booster to make it fit and look stock.

I also had some idle issues. Make sure that the linkage is not obstructed (sounds like it is based on your “groove” description. My cable was just a little too tight and the butterfly valve was not closing fully. Adjust the throttle cable with the engine running. and make sure that the throttle is actually closing completely.