Bad Idle, My Help Thread.

[SHO Nick]

Alright Ive had serveral problems..and well Im gonna make one thread, and stick with it..this way all the great members here dont get confused, and know that I need help in this thread.

Alright, Here goes...
I know I have these problems...
- Y-Pipe Leak
- Possible Intake Leak
- Coolant Leak(Small, and will be fixed)

Would either of the leaks cuase my Idle to run badly? Sometimes upon a cold startup it will rise quickly to 1500rpms, then after a second that the cars been on..will drop to 600rpms and run really rough..then after its warms...will run around 1000-1100 rpms, and kinda normal, but odd then Drop Suddenly to 600 RPMS and run rough and jerky...
My friend thinks that a intake leak wouldnt cuase a sudden drop in RPMS like that after the car is running for 30 seconds at 1000 rpms...

My theory is thus...put back the stock computer and remove the tuned one(that mind you was pulled of a different SHO with a few more mods like y-pipe which i dont have), and buy another intake, and put back the horns and fix the intake leak. If the idle is still rough fix the intake leak...if that doesnt fix it..maybe a sensor Then if the problem is fixed, put back the 80mm MAF, and a recalibrated comp. and see if the whole problem is fixed...

If anyone can give me advice or save me the time and trouble & money of buying a diffent un-dremeled intake please help me in anyway.
-Nick
P.S. So sorry to keep posting, but I am acustomed to the post and reponses of larger site like StangNet.com...

 

[yamahaSHO]

I sure hope you got that car cheap for all the immediate problems you are having....

fix the intake leak. If the idle is still rough fix the intake leak...

I hope you should only need to fix the intake leak once.

An intake leak can cause an erratic idle. I'd deffinitly put all the stock stuff back on and see if it still does it. If so, consider cleaning or replacing the Idle Air Bypass. Im willing to bet the LPM/80mm MAF is giving you some of that problem.


When did you first notice this problem? Did you change something?

P.S. So sorry to keep posting, but I am acustomed to the post and reponses of larger site like StangNet.com...

It's not so much the posting, it's the fact that many of your previous questions could be answered even sooner by searching the forum.

 

[SHO2]

Have your crank sensor checked out

 

[yamahaSHO]

Have your crank sensor checked out

Crank sensor would cause the car to have problems starting.

 

[munkee]

Your sig says you have a 49 state ECU, I assume that also means the EGR valve is no longer there right? I had this exact problem in a california mtx that I never figured out. I swapped the motor into another car using a different intake and it ran really smooth then. Like Jason already said, fix that intake leak and clean the IAB. Have you pulled any codes?

 

[SHO Nick]

I cleaned the IAB before I did the intake swap, and it improved the idle, so when it dropped suddenly it wasnt as bad as before when i didnt clean it...I had also sprayed the entire intake system with carb cleanter thru the TB..I have my money on the ECU aswell...my plan as stated above is to get a stock intake, and put back the COMP and Stock Air box. Then fix the Exhaust Leak...if that fixes it..then slowly put things back and find out what the problem was...

Also, the EGR Vavle is on, but the vacumm is not connected due to the 80mm MAF, and the fact the the EGR part that is near the stock air box was not given to me at the time of sell since it was non-working.

Lol, I bought the car for abour 3 1/2, but ohwell..Im not really upset at the seller..I have no reason to be..I knew what I was getting in..just kinda wierd since I got all these problems that he never got..ohwell..time to fix...

 

[SHO Nick]

Alright, I wont make any other threads as long as I get respones here...

UPDATE:
Just got off work, and put back the stock Air Box, and Computer on. The one installed with the chip is a Reman...and ill get the specs later for you guys..with the Stock Air Box & Computer Installed, it improved the Idle and make it smoother..for about 40 Seconds..then once again Suddenly the RPMS dropped faster that you can say "cat" to a Loping 600RPMS... ...........Besides the ongoing exhuast leak and possible intake leak...could the IAB that I cleaned be bad? I might try and pick one up at the junkyard when I get the other intake to put back on the car...and see if a STOCK Intake, and a different IAB helps...

Also, could someone supply with the Torque SPECS. Ill need to install the intake? That the torque specs for the secondarie butterfulys, and the upper to lower intake bolts...
-Nick

 

[AREA 91]

11 - 17 ft lbs

 

[SHO Nick]

11 - 17 ft lbs

That sounds kinda light, is that factory or optimal?

 

[yamahaSHO]

That sounds kinda light, is that factory or optimal?

That's what Helm's says.... Factory would be optimal.

 

[SHOman24v]

if you want i can fix it, your problems are very small, its werid how i never had these problems....... There should be no problem with the reman ecu. i had it in for about 3 months before i took it out to smog it, remember you need that egr control solonoid (that you dont have) with the stock ecu or the car will not run right

as for the torque specs, tighten till you feel its right but dont tighten the crap out of it, for intake parts, i never used my tq wrench, it just didnt feel right... but thats how i work

 

[munkee]

Aluminum threads will strip pretty easily before it ever "feels" tight, although if you do it enough, you can get a good feel for it. It's best to tighten with a torque wrench to 11-17 ft. lbs. You need to either completely remove all of the egr components , including the CA computer and capping off the vaccuum lines, or reinstall everything. That is likely the cause of of your problems, if not a bad IAB.

 

[AutoSHO]

You took the chip out when you put the stock airbox back on, right?

 

[SHO Nick]

You took the chip out when you put the stock airbox back on, right?

Yes I did...I took off the chip and installed the stock ECU back on.

*Update* This morning before work, I decided to buy a new IAB from Kragen's...$50.00 Later...I recieve a Perfect(to my standards) Normal Start-up and Idle from a Cold start, but after no more than 30 second, the 600RPMS Lope Starts Again... What could cuase a normal idle to dip down so fast and sudden?

I know I have a Bad Y-pipe bolted in, and a Possible baby intake leak..A sensor? O2's maybe? I also have my EGR sensor that hooks up to the air box off and all the vacumm lines are blocked off.

Grrrr....help...Grrrr....

 

[AutoSHO]

You cannot use the California ECU in that car unless you reinstall the EGR system... It will never run right. Leave the 49-state ECU in and just pull the chip out of it.

 

[SHO Nick]

You cannot use the California ECU in that car unless you reinstall the EGR system... It will never run right. Leave the 49-state ECU in and just pull the chip out of it.

Will Try that tommarow morning in hopes that It helps!

 

[SHOman24v]

(very confused)

since i know the car the best, i can tell you its not the idle air control motor, the ONLY think i can think that it will ever be is the EGR, you HAVE to make sure that its completely SEALED your you will get POOR IDLE, its a fact, unplug one of the vacuum lines to that intake and you will notice a loss in idle quality. It the CA computer is installed you MUST make sure that the EGR is working properly and is hooked up properly too, if something is backwards it will not run right.

If you plan on running the 49 state LOS pooter, you MUST make sure that you either use a 49 state plenum or make block off plates that fit properly and seal good or the SHO will never run right. If you go this route id recommend using a good RTV sealer that can handle heat, ESPICALLY were the EGR bolts to the exhaust manifold, actually id recommend making a paper gasket for that one, using one of the gaskets in the kit you have. (I think you may have one its looks like the EGR one but slightly smaller)

You have to remember the car is old and you wont get that silky smooth idle quality of a new car, but what i would recommend is before the next oil change buy yourself a quart of high quality ATF and dump it in the oil, drive it around for a few miles to get it through the engine, the detergents will clean up the parts real nice. I remember when i did that but i also sucked up seafoam in the intake to clean the carbon, the idle was amazing.

My first and foremost recommendation is to set the car up exactly back to the way it was when you got it, you can fix the EGR by using some blue RTV on the EGR gasket as a temporary fix for now, IM SURE that if you go back to the way it was there will be no problem, and make sure that old radiator cap goes back on, i think thats the reason for the condensation on the windows and leaky radiator (being that those parts are about a year old), i hope that cap didnt **** the heater core cause doing that job is a B**CH espically when its a 30 dollar part your trying to change

try what i just said and you will be

 

[SHOman24v]

fill us in soon.....

 

[SHO Nick]

Ill Reply Tommarow...

I Should be able to get an Oil Change, Fix the Small Coolant Leak, and Tinker With the Y-pipe for sure tommarow, and hopefully make a trip to pick up another Intake too...

I highly doubt the Coolant/Radiator Cap has to do with anything...its rated at the same pressure rating as the one that came with it, so it cant be that..maybe I just got the car at a bad time and you sold it at a good time? Ohwell...My Loss Your Gain...

 

[SHOman24v]

I dont understand how all these things are happening when pratcially all the parts on that car are new, and everything is in good condition

for your idle problems, make sure the intake donuts are on snug, you put the intake back on properly by using the method of keeping everthing loose and tightening in stages, and all the gaskets are present.