HellO,
I have a 91 z28 350 Tpi. It was original auto, but converted to world class t-5. I cannot get idle to go below 1300 rpm. I have replaced
Idle air control valve
TPS sensor
Distributor
Spark plugs
Brand new injectors (stock 22lbs)
Alternator

Anything to do with idle ive changed as well as made sure my timin is 6* BTDC.
Any ideas and also since its now a converted stick should my timing change to accomadate the high idle? My understanding is manuals idle around 850 rpm. Thanks guys

 

Few ideas:

Minimum idle air adjustment.
TPS voltage adjustment.
Vacuum leak.
Timing will be the same, auto or manual.

 

Wheres the aldl port to use the paper clip on?

 

Ok so today i tried to set minimum air setting.. I connected ports A&B on the ALDL ( i think it was the ALDL not 100% sure
As ive never messed with it b4) i followed the steps and when i started the car with no IAC valve connected it steadily idle around 2000 RPM. I have the idle screw backed out all the way as well but still have high idle =[ i dont understand why it was idling at 2000rpm with no IAC valve, could this point to the real problem !?

 

Well with no IAC you are letting even MORE air bypass the throttle. There is a tech. article on here describing the reset procedure: https://www.thirdgen.org/tpimod2

Here is what my Chilton recommends:

-Pierce idle stop screw
-Make sure IAC is connected.
-Short the A and B terminals at the ALDL. (Near steering column)
-Turn key on, do not start engine. Accessories only.
-Wait 30 seconds.
-Now disconnect the IAC with the key still on.
-Separate the set-timing connector to prevent and changes in engine speed due to variations of engine timing (because you will start the car next)
-Start engine and remove the wire shorting the A and B terminals. May have to hold the throttle open slightly to prevent the engine from stalling.
-Allow engine to reach operating temp
-Now adjust idle speed to 400-450 RPM (for 5.0 and 5.7 liters)

-shut off engine, connect IAC harness.

 

Thanks so much fro man. Do u think u could post a picture of the ALDL port ?

 

http://www.justanswer.com/uploads/ca...05626_dlc1.jpg

 

Would indicate a vac leak if you you can't pull idle down with IAC disconnected
Are the throttle blades fully closed?

 

Timing is different between auto and manual. Base timing is the same tho,but spark maps are different. So are the fuel maps

 

Throttle blades are fully clOsed. Had it hit with a smoke machine and found a lil vaccum leak, and that the lines to my egr were somehow modified... Back to the shop tomorrow to have them redo my vaccum lines will update tomorrow !!

 

You need to reprogram your ECM Memcal for a manual Transmission. There are lots of programming differences between the two transmissions. There never was a manual transmission for that SD 350 engine so the Stock AUJP will not be correct. Check the for sale section for a memcal.

 

Jus wanted to update everyone on what has happened. Car passed smogged, apprently i had no high idle the RPM guage wasnt accurate. Did some research and it does happen to these tach's a lot so HEADS Up!! Also i didnt need any chip at all for my conversion (auto to manual) my car is pulling hard thru all gears ! YEEYEE !!!!!

 

Still doesn't fix the problem of having the wrong programming for the ECM. There are big differences between manual and auto programming especially in the IAC and deceleration spark and fuel. It may seem alright to you now, but it isn't until you get the programming done.

 

Ok im a noobie when it comes to chips. What exactly do i need to buy and how do i install it. Thx.

 

Go to the DIY prom section for details.

Basically you need to buy a chip burner and a chip adaptor and then burn the 91 corvette 5speed tune (AXCN) using Tunerpro RT(free).

You should get a datalogger cable and then fine tune the AXCN bin to your application.

You could also just order a custom chip from one of the forum members(not me) if you don't want to mess with this stuff.

 

I did the auto to T56 conversion in my car which used to be a 350/Auto. I'm also burning my own chips. The differences between the auto and stick programming are that the IAC settings are different between the two. The stick tune has specific subroutines for limp home mode, etc. For me, running the auto tune in my stick car, the car would stall out once in awhile when I would push the clutch in.

I'm in the process of adapting a Corvette AXCN stick tune to my car right now. I would not recommend that tune with its aggressive spark tables for an iron head motor. (I have Aluminum heads) Would be a quick way to go BOOM. Your best bet might be to get a 305/5-speed AXXF tune and copy the 350 specific items such as fueling curve and spark curves over.

 

There are lots more differences between an auto tune and a manual tune besides the IAC settings. Spark tables are totally different, fueling,etc,etc.Corvette usually has an oil flag that needs to be un-set or else you may get an SES light.

 

Yep I know, I only copied the IAC strategies for manuals. The spark and fueling are all custom by me for my particular setup. (Not a stock L98 anymore) I've since started playing with the sAUJP bin and it actually works much better with with my spark and fuel curves and the vette iac strategies.

And the Vette SA tables weren't all that much different manual to auto. For some fun, I tried running the iron head L98 VE and SA tables with the vette bin. Worked pretty good.

If the OP doesn't know how to tune chips, you can start or you can have fastchip or ed wright burn you a manual program for a 350 with iron heads.

 

Where can I contact Fastchip or Ed wright? Im doing the same to my 89 GTA convertible 350 auto...soon 5 spd

 

After you get a new chip burned, get some 3.42 gears and a full exhaust system then watch how much power and pull through the gears you will have. The car will run in the low low 13's@106mph.