Engine Ticking

[XfireZ51]

Originally Posted by Dmod81

All of the pcv parts are new and attached snugly, but there could be a leak somewhere. I'll see if I can find a leak with a homebuilt smoke machine or something.

I bought my first ZR-1 and it ran fine but had a bit of an annoying idle hunt. Not bad and could easily have been ignored but I'm a bit finicky on that.
At a Haibeck BBQ, Marc told me it was likely the PCV F connector. He was right.
Look to zip tie those and see.

[Dmod81]

Just tried that out- no change. I had the old connector zip tied, but this new Jerry's one is really tight. Checked the pressure regulator vacuum line, that was good. I also took a look at the inside of the grey ecm connector. I couldn't really tell if those were spread out too far. I haven't backprobbed them, but the previous owner might have. But then again, if it was that why would it act up now?

Seriously, with respect to the engine when I was fixing the first miss,the only changes I've made is new starter, new alternator, new coils, new wires, new purge vacuum lines, new passenger vacuum line to the plenum, ported intake, remove secondaries and new chip. Seems there shouldn't have been any issues after this.

Then as I had a rough idle after the fix, I've replaced pumps, filter, injectors as tests indicated these were questionable. I've also replaced the IAC and cleaned its bore, and TPS and O2s. I'm at a loss. My wife is really pushing me to drop the car off at the Oxnard Carmax.

[XfireZ51]

Originally Posted by Dmod81

Looks like I have spoken too soon about it running great.

Symptoms (other than the slightly high idle that will go back down after a small tap on the throttle):

Miss every few seconds at idle (rpms will drop about 20 on tech 1)
Every once in a while it will stumble and almost die at idle
After coasting, when I get back on the gas, it will stumble and buck until it clear out and runs normally again
Smooth operation in normal driving and heavy throttle

KOEO pressure is 0 psi, slightly over 40 at idle
Both pumps run when tested
Car starts normally



It looks like the book points me to the hoses in the tank (entire new pump assembly was installed in April 2013) or the fuel filter (new installed April 2013), but I wonder if I might have a bad injector (s) too? They're accells that were installed at the same time as my failed coil (Sometime in late 2008 I believe)

OK. So you had the top end ported. Do you have a scantool? What are your IAC counts? At idle, what is the TPS V?
Whenever you change the airflow in the motor, the Min Air throttle opening needs to be re-set which in turn affects the TPS voltage. And if the TPS volts are not below .59v at idle, the ECM does not invoke the Idle routine which includes timing. Or it could be on the edge of in/out idle. If its dying at idle, the IAC may not be able to keep it alive if throttle isn't open enough.
The basic settings on the motor need to be within spec before anything else.

[Dynomite]

Originally Posted by XfireZ51

I bought my first ZR-1 and it ran fine but had a bit of an annoying idle hunt. Not bad and could easily have been ignored but I'm a bit finicky on that.
At a Haibeck BBQ, Marc told me it was likely the PCV F connector. He was right.
Look to zip tie those and see.

If you want to do it "right" get rid of the old PCV hardened rubber connectors and install new soft rubber connectors without using hose clamps or nylon ties of any kind Jerry has them all

PCV Upgrades

[Dmod81]

The IAC counts at idle are 25, cold open loop. The TPS voltage was at .50, which is weird because I set it at .54. With the engine off and pressing and releasing the throttle it settles at .52 or .54. The last time I drove it on sunday, I noticed the IAC counts were 3 at hot closed loop idle. This was after restarting after it stalled on me when turning a corner.

How do you set minimum air? I don't think I've done that.

Dynomite- I've got all of Jerry's parts for the PCV system- they are great. The old parts just kind of stretched/fell apart in my hands.

[XfireZ51]

Originally Posted by Dmod81

The IAC counts at idle are 25, cold open loop. The TPS voltage was at .50, which is weird because I set it at .54. With the engine off and pressing and releasing the throttle it settles at .52 or .54. The last time I drove it on sunday, I noticed the IAC counts were 3 at hot closed loop idle. This was after restarting after it stalled on me when turning a corner.

How do you set minimum air? I don't think I've done that.

Dynomite- I've got all of Jerry's parts for the PCV system- they are great. The old parts just kind of stretched/fell apart in my hands.

IAC counts for idle need to measured at 80+C, closed loop. .5v is a little low for TPS. I set mine at .53-.55v. The TPS needs to be, at minimum, re-checked and possibly re-set after each time you set throttle opening.
Min Air must be set so that the motor idles just under the point where it does not require IAC opening. You'd like to have IAC counts 10-15 at operating temps and idle. I set the throttle opening with fans running, putting an additional load on.

You can do a search on Min Air adjustment. I posted a step by step procedure for doing that. The set screw for throttle opening should be replaced by a hex bolt which would allow you to change throttle opening w the motor running.

[Dmod81]

OK, so I replaced the throttle stop with a bolt and ran through the procedure you have posted. IAC counts are now at 12, and TPS at .55 volts. The car is more responsive and seems to not have a tendency to stall going into a turn anymore.

I still have what feels like a miss randomly every 10 seconds or so. It just sounds like the car misses a beat. However, sometimes it does not do it at all. I've added techron cleaner and water remover to the tank, as I had the fuel system open for a couple of months while waiting for parts. I'll see if that does anything. Also, the gas on base is not top tier, so that could contribute, if this is some sort of bad fuel issue. Otherwise, everything checks out (as far as I can tell), injectors are firing correctly, and it doesn't look like I'm losing spark when it misses. Any thoughts?

[XfireZ51]

Have you tried Sea Foam?

[Dmod81]

I have not, but I just got a can of the stuff that you can spray into the intake. It has the long straw with the bend in it.

[XfireZ51]

Originally Posted by Dmod81

I have not, but I just got a can of the stuff that you can spray into the intake. It has the long straw with the bend in it.

Yep!