Engine Ticking

[Dmod81]

Just a little update:

I ran through the fuel pressure test procedure and was getting almost instant leakdown, so I replaced both pumps. Now I get 52 psi when the pumps are running, which drops to about 43 when the pumps stop and holds there with very slight leakdown. Pressure at idle is about 42. I also replaced the fuel filter. Rough running/miss at idle still there.

Finally I replaced the injectors. There was some crud in the rails that I cleaned out. I also checked my plug wire routing/reseated the wires, replaced plugs, O2s, and checked all other connections/vacuum lines. All seemed good. Rough/miss at idle is still there, but it might be very slightly better. However, the stumble with throttle after coasting is MUCH better. Almost non-existent.

As a kicker- I now have a very large screw in a rear tire. Must be a gift for driving the car only 40 miles over the last 4 months trying to fix it. I think something is trying to tell me it's time to throw in the towel.

[XfireZ51]

You're sure you don't have a vacuum leak like at the PCV valves?

[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.

[LGAFF]

Will apologize if its been discussed as I did not read the thread, but sounds like a MAP sensor issue;either a rotten hose on the primary or under the ECM

[Dmod81]

No worries - I don't believe it has been discussed, although the map and the hose (plastic) are relatively new. The MAP seems to be reacting correctly on the tech 1. The sensor under the ecm is open to atmosphere, as I've eliminated the secondaries (That is correct, right?)

[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.

[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.