So i work on cars all the time but this one is stumping me. This is my personal car and is having problems idleing in gear. It idles great in park nice smooth idle but when you put it in gear it bogs and falls on its face.
Parts changed:
Cap and rotor set from accel
8mm wires from accel
New nicle ngk plugs
Ignition module
New bosch 3 injectors from southbay
New iac valve
Temp sensor
Temp switch

I have adjusted timing and iac car coded for a bad throttle position sensor so im replacing that when it gets here. Could that cause the problem? If i keep my foot on the gas it will shift into gear then i cam remove my foot from the gas and it will idle in drive but then when i shift from gear to neutral it dies then as well. Its odd...

 

You can test the TPS with a voltmeter before replacing it. I would also check the vacuum line for the map sensor for leaks and if that checks out, check the map sensor voltage. I would suspect it has a skewed reading.

 

Has new map sensor as well forgot about that. What should its voltage be? And what pins to test on both?

 

tps voltage is critical. anything over .69 and the ecm thinks you are 'off ildle', and therefore inhibits iac function. replace the tps, adjust it properly, and recheck

 

Well then maby thats my issue ill have to replace the sensor and check voltage. I was told its non adjustable on a 91 l98 tpi is that true?

 

Im not sure on a 91. If the mounting holes are oblong(slotted), it is adjustable. Verify with a DVOM that you have between .51 and .67 at closed throttle.

 

A 85-89 tpi tps will work on a 90-92 sd setup. if should be a non adjustable tps. Koeo the feedback blue wire is .66-.76vdc. Did you ever check the orange/black stripe wire that I suggested on your shifter p/n switch as I suggested on your other thread ?

 

I did check the p/n switch and it seems fine but... i just went to reset the base idle and i jumpered the aldl and waiting 30 sec then turned the car off removed the rumper unplugged the iac and started the car and hear a very loud whistle sound because the intake was off and the iac was full open now your probably think well thats not right and so am i... What i think has happened is the plug for the iac was broken apart when i got it and the wires could be pulled out i think the wires have been crossed and when i switched the connector they stayed crossed and now the computer tries to open the iac and intern closes it instead. Seems like a valid theory to me but how do i fix this newly discovered caos? Thanks for all your help so far guys. Ps new tps is on and with throttle all the way closed its at .68 volts normall or no?

 

https://www.thirdgen.org/forums/tpi/...t-iac-use.html
This shows the wire color position for the iac.

 

On my car the wires are green with a stripe. Pin A is green with White stripe Pin B is Green with Black stripe C Pin C is green with White stripe and Pin D is green with Black stripe.

 

How did you adjust timing? If it's retarded it will die in gear

 

Its set to 6* BTDC with it unplugged. Im pretty sure the iac opening when the aldl is jumped is the problem because thats 100% backwards...

 

And you verified it's the correct balancer & timing pointer? Balancer not slipped? Set it to 12, just for ***** n giggles and see what it does. If it's better, you are in for a piston stop and marking the balancer. Wouldn't be the 1st.

 

Already marked the balance and it has not slipped and the timing tab is in the same place as my friends 91 l98 tpi camaro.

 

That does not say anything, if you have the wrong balancer it's still off. How did you mark the balancer? Did you use a piston stop to determine TDC?

 

Yes i used a piston stop to determine top dead center and the factory marking on the balancer is still accurate. The timing mark is also correct and the timing was set to factory setting on the stock camaro correctly........ Im currently adjusting the timing to see if there is any change better or worse.

 

Ok so i rewired the iac and the car still dies when first put in gear... I unpluged the timing advance plug so i can check the timing and thought id see if it goes in gear and it does. With the timing set at 6 BTDC it goes in gear just fine but when i plut it back in the computer sets the timing at like 16 BTDC and it dies when you put it in gear. Should the computer retard the timing that much at idle?

 

Are you saying the timing is going retarded when the esc is plugged back in ? Or advancing ?? If its going retarted you may have a false knock or the icm is wired backwards.

 

Its going retarded not advance. So i should check wiring on ignition control module and maby replace knock sensor?

 

if it goes from 6btdc to 16btdc it's advancing, as in the spark occurs earlier. You have the terminology swapped around.

 

Woops well that was a derp. Thanks turbo.

 

So why would the car not go in gear with the esc plugged in but with it unplugged it goes in gear flawlessly

 

I had a 92 rs tbi car that would do the same thing.

In my case it was a bad pick up coil in the distributor.

 

Will replace the pick up, knock and o2 sensors today hopefully the parts stores have it in stock haha.

 

Replace one part at a time.

 

I have been doing that just nickle and diming the crap out of the car. Now i need the car running and driving by monday or i have to walk 11 miles from school to work haha

 

I haven't seen it mentioned, but have you pulled codes?

 

Shows a code 12.

 

I would quit throwing parts at the car. Unplug the ks is the timing still retarding ? Yes , then swap the pu coil wires. You may have to brake off the connecter latch or just repin the wires.

 

I dont mind throwing parts at it since most of the parts on the car are from 91 and should be changed any ways to improve reliability. What do you mean unplug the ks?

 

Squeeze the connecter on the knock sensor and unplug it. Try putting it in gear or use a timing light to see if the timing is retarding. If it still is its not the knock sensor. It would be a back azz words wiring of the up coil.

 

Knock sensor.

 

Thought about it after i posted been a long couple days thought proces is gone sorry guys. And the car is advancing the timing 10 degrees with the esc plugged in as turbo pointed out i had my terms backwards. Will see what happens with knock sensor unplugged any way thougj

 

The Timing advancing is normal, the ecm takes over when the esc is connected back in. It just used the 6dbtdc as a base setting. depending on ect, map kpa will determine the target advance. I like to run as much timing as I can get without knock. A marble in a tin can sound lol.

 

Trying to change this pick up coil but having a problem. Shouldnt the shaft of the distributor pull out of the midle once the gear is off? And ill be uploading a pic of the distributor in a minute to see what you guys think

 

Ok couple questions...
1.Does that pin being broken matter(The one in the back just left of the shaft)
2.Should the distributor shaft have these groves on it
3.Why does this crap rust so badly???

 

That looks pretty nasty!
I'd price a new dist.

 

The rust is because the metal is untreated, degrease and clean the groves in the shaft and reassemble with light coating of engine oil. The base is just oxidation I would use comet or 00 steel wool. Remove the shaft first or the steel wool will cling to the magnet. As ling as the shaft is tight in the bushing side to side clean it up. Up and down movement when assembled iirc .016 is about spec. A pickup coil is cheap the one terminal looks corroded . There is a centering plastic pin that often breaks when the up is removed. Make sure thats out before assemble. Destroy the locking clip with a pair of dykes and reinstall the new one with the up. you can use a socket and hammer to install it. make sure you apply heat sink compound under the icm apron assembly . A refurbished dizzy is usually around $100 but if the icm is new and the bushings are tight I would put the $25 or less in the pu.

 

Just a heads up I have seen the magnetic pole crack before on this tbi!tpi hei.. that can really effect timing. There is a updated rotor to help keep moister out of the cap aswell.

 

They did make a rotor for gm small cap remote coil tbi and tpi to help with moisture acdelco D461 gm 10477219 the bottom of the rotor has fins to help move air and moisture out the bottom of the distributor base vent screens. I would only use this if it was a constant issue or in a 4x4.

 

Off to buy a dizzy 110 at autozone. The magnet on the distributor was broke in 3 places

 

 

Sweet baby back ribs its running great!!! With high beams on, both fans on, heater on full blast and dome light on car doesnt even flinch when i put it in gear!!!!!!!!!!!!!!! Greatest feeling ever. Thank You guys so much. Now i have to see if it will pass smog.....

 

You found the issue, and learned the difference from advance and retard lol, no I was not name calling.

 

Haha yeah yeah thanks tuned. Im going to spend tommorrow rewiring the fans back to factory...

 

https://www.thirdgen.org/forums/tpi/...an-sensor.html
The fuse for the relays is located next to the battery

 

The stock fan wiring in not being used at all

 

https://www.thirdgen.org/forums/elec...co-91-z28.html
Are you wiring up a manual switch or something ?