Lucid

iTrader: (4)

I am not really sure where to post this because it's both TPI and tuning related.

Long story short, I bought this car and tuned it about 10 years go. Smooth idle, ran pretty strong. Recently I was doing routine maintenance and found that the PO had stripped out one of the thermostat holes to about 1/2".

My buddy and I tore it down and ended up replacing the lower manifold with the same part number, a new timing chain, harmonic balancer, and put in an LT1 camshaft that he had laying around. I reused my existing valvetrain otherwise. I put new screens in the factory Rochester 19lb injectors and new orings. We ended up breaking the hard lines going from the EGR solenoid to the EGR valve and under the plenum to the throttle body, so I replaced them with rubber vacuum lines. In order to transfer the EGR valve to the new manifold, we had to take the EGR temp switch off and the little contact screw came out, and we threaded it back in.

I put in a new Coolant Temp Sensor and capped off the cold start injector on the rail and the runner with a delete kit because the replacement manifold was missing the cold start switch port.

I started it up, we set the timing to 6*degrees (what I have programmed in the chip). It seems to be running pretty well. I have a 180 degree t-stat installed and the fan on temp to 220 and off at 210. The ECM reports 176 degrees as the coolant temp when the fans come on, so I will have to look into that.

I got Tunerpro and WinALDL running finally on my laptop and after the 3rd start I noticed that the SES check engine light comes on as soon as I start it. I'm also noticing that even after running it at idle for awhile, Tunerpro reports that it's still in open loop and the BLM and INT are locked at 128. The code reported in Tunerpro and winaldl is code 32, the EGR circuit.

So I am thinking that when we screwed the pin back in, we went too far and maybe it's contacting the bimetal element inside and grounding the circuit, triggering the code 32 at startup. I unchecked the flag to disable the code 32 and burned a new chip, it still will not go into closed loop.

Would the ECM still detect the malfunction and disable closed loop operation or is something else going on?

Also, is it possible to edit the Tunepro datastream file to add an item for EGR Diagnostic temp switch to show if it is closed or not? Winaldl is showing a checkmark on the EGR diagnostic switch closed as soon as I turn the key to run.

I am not too familiar with the LT1 camshaft other than the lift specs and the LSA, but is the camshaft cooling off the O2 sensor? It's showing not ready for the duration of the runtime in Tunerpro.

RBob

iTrader: (1)

The o2 sensor is showing activity at below 300 mV. It is rather common for the ECM to not go closed loop after a start up and during idling. Try either revving the engine a little, hold it at say 1400 RPM. Or take it for a short drive.

As for the EGR error, I have no idea what is going on.

RBob.

Lucid

iTrader: (4)

That seems to be the case. My 86 would go into closed loop during idle so it was really weird to me.

As for the Code 32, my friend told me he turned the contact pin all the way in. I removed the plenum (again lol) and check for continuity from the body of the EGR diagnostic temp switch and the middle terminal of the wire. It showed a direct short (grounded). So I backed the contact pin out until it no longer showed continuity (about halfway) and applied some RTV to try to keep it in place. I tried to use a 6-32 nut to hold it in place but that nut wouldn't thread in for some reason.

I buttoned it back up and turned it on and no more code 32. This LT1 cam pulls really hard compared to the peanut cam.

I got the idea from this site on code 32:
http://chevythunder.com/fuel%20injec...temp%20sw..htm

ULTM8Z

No closed loop at idle could be due to a number of things...

Bad O2 sensor

Bad O2 sensor ground (ensure the surface the O2 is tightened against is clean and bare metal

A break in the O2 output wire somewhere between the sensor and the ECM connector

Full length headers with a non-three-wire, non-heated sensor in the collector (not sure if you're running headers)

Lucid

iTrader: (4)

The O2 sensor is switching back and forth. I don't think it's bad. When I held the throttle open to 1500 rpm like Rbob said it went closed loop for a bit and I saw the BLMs drop to 108. I'm going to have to drive it around and do more datalogging. I just haven't trusted the car enough to drive it far. It's got factory manifolds but I'm unsure if the cat is gutted or not. I've been tweaking the crank pulse width and crank settings because I had the cold start injector hooked up before and it started easier then. I'll get a winaldl log soon.

Dominic Sorresso

Mine sometimes does the same thing even tho its at operating temps. A simple blip of the throttle and good to go.

Street Lethal

iTrader: (16)

Though odd, this sounds like your culprit, though I would first confirm your coolant temp mechanically with a good gauge to compare it with what the ECM is seeing by way of its' sensor. Closed Loop is timed in the bin during cold and warm starts, but even when that counter reaches zero, Closed Loop won't enable until a certain temperature is met first. If your fans are programmed to come on at 220-degrees, but are coming on at 176-degrees instead, then that is a 34-degree discrepancy. Closed Loop enables lower than 176-degrees, I don't remember what that programmed value is, but if your ECM is reading 34 degrees lower than what it's programmed to by going by what temperature the fans are kicking on, then that 176-degrees (which the ECM somehow see's as 220-degrees using your fan value) is really much closer to 142-degrees, 34-degrees less, when the ECM is reporting 176-degrees from a Closed Loop perspective. You're right on the borderline of Closed Loop if this indeed is the case, which explains why you're hitting Closed Loop when holding the throttle...

- Rob

Lucid

iTrader: (4)

Yeah I'm not sure why they are kicking on so early. We installed a brand spanking new Coolant Temp Sensor when we redid the intake. I'll have to look at the BIN again to see if there is another reason they are kicking on. I'm not sure why, but I've had to lean out the cranking tables to get it to start because it was way too rich.