Re: Engine Ticking
 

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.

Re: Engine Ticking
 

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.

Re: Engine Ticking
 

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.

Re: Engine Ticking
 

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 :thumbsup:

PCV Upgrades

http://i287.photobucket.com/albums/l...a48835bce4.jpghttp://i287.photobucket.com/albums/l...1cd951b2e6.jpg
http://i287.photobucket.com/albums/l...4769bcd3e7.jpg

Re: Engine Ticking
 

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.

Re: Engine Ticking
 

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.

Re: Engine Ticking
 

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?

Re: Engine Ticking
 

Have you tried Sea Foam?

Re: Engine Ticking
 

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.

Re: Engine Ticking
 

Yep!

Re: Engine Ticking
 

I also removed one of the oil tube hoses and sprayed it through the the airborne opening. Just need to keep motor running.

Re: Engine Ticking
 

The bog after coasting is back (well, actually, when I thought it was gone, I wasn't off of the throttle enough for it to appear, still have a rough idle as well). It bogs if I let off the throttle and for more than about 3 seconds.

I finally got some time to datalog the car. What I think (because I have no clue how to really interpret the graphs) I'm seeing is that when I go off throttle, the O2s either go erratic, or low or high, and the integrators start dropping sharply. Then when I get back on throttle, the RPMs don't increase until the integrators start coming up some. Also at cruise, the O2s are cycling only about once per second (thanks to Marc for pointing that out).

(Integrators, RPM and TPS % on top, and O2 voltages and map on bottom)

Bog 1:
http://www.zr1.net/forum/picture.php...pictureid=2917

Integrators dropping further the longer I'm off throttle:
http://www.zr1.net/forum/picture.php...pictureid=2918

Everytime you see the throttle being depressed here, the car was bogging until the integrators got back up to normal and the O2s started cycling again:
http://www.zr1.net/forum/picture.php...pictureid=2919

Cruise:
http://www.zr1.net/forum/picture.php...pictureid=2920

Re: Engine Ticking
 

So you ported the top end, what changes were made to the calibration?

Re: Engine Ticking
 

I have Marcs normal BPPAG4 cal with custom settings:
Add fuel for headers
Fuel for cats
Enable anti-backfire mode
Add Fuel for top end porting
Secondaries removed
750 rpm idle
7200 rpm rev limit

Re: Engine Ticking
 

Just a shot in the dark..What brand of O2 sensors are you running?

My car, after porting it, did exactly the same thing.

There is a thread on the forum about the recommended O2 sensors, I put those in and no more problem.

Re: Engine Ticking
 

They are new densos. I had the same issue with the old ones that were in there too, but I'm not sure which brand those were.

Re: Engine Ticking
 

OK, so I replaced the O2 sensors with OE type AC Delcos and also tightened the header bolts. Several were slightly loose. This seemed to have helped the problems a lot, but was not a 100% fix. It stumbled only once on the test drive, and there was no ticking or missing to be heard.

Unfortunately, on the next drive, everything was back to how it was before. So I seafoamed again and noticed a small amount of smoke was coming up next to the engine on the passenger side. So I took a look and noticed the header flange at #6 is dirty and wet:
http://www.zr1.net/forum/picture.php...pictureid=2957http://www.zr1.net/forum/picture.php...pictureid=2958

Sorry for the poor quality, I was using a cheap snake camera hooked to my phone. For comparison, here's #4 and #1:

http://www.zr1.net/forum/picture.php...pictureid=2959http://www.zr1.net/forum/picture.php...pictureid=2960

So its really only # 6 that is wet. Is it possible that after I tightened the bolts they loosened up again/ or the gasket is now damaged? Could a leak there cause a miss and stumble after getting on the throttle after coasting? I find it interesting that that cylinder is the one that had the original dead miss.