lt1 issues at low rpm (video)

[bennett28]

I am new to V8's, this has been my first. I have been a DSM man (1G's mostly) for about 8 years. Wanted to try something diff and more reliable, lol. Loving it so far, just ran into this issue which has been the first issue since I have had the car for a year. After deleting the EGR and AIR out of the car and redoing the intake gaskets(It started leaking on me) the first crank up it started the issue. Went to clean MAF with some q-tips and reset the pcm, then car was fine, went for a drive and the video explains what happens. It's a 1994 obd1, but SES still came on for AIR and EGR. Heard it's luck of the draw on obd1s. Had it scanned and those were the only codes. I deleted the egr becuase I thought it was going out because this problem was happening before, but lightly and only around 2k.

Car is a 1994 camaro z28 A4

http://www.youtube.com/watch?v=x9PFnW0DMHY
There's a video I made today(sorry hard to see, sun was very bright today) of the issues I'm having. The issue seems to only happen in closed loop. Well, closed loop to me, I haven't gotten the chevy lingo yet, but seems closed loop to yall is thermostat related. where in a dsm it's when ecu shuts off all emissions extras in high rpm. Basically I'm saying if I WOT, it doesn't do it and runs prefect.

In the video I was very smooth with the throttle from 2k to 3k, all jerking and rpm bouncing was done by the car.
This starts happening sometimes at car start up or after 30+ minutes of driving. I did a WOT pull to 120mph and a few minutes after driving slow back home, it started again.

This happens from 1.5k rpm to around 3k, with the worst happening right at 2k and 3k. At WOT car is fine. Can't really tell if this is surge, jerking, hesitation, or misfire.
Also at a light or stopped the volt gauge will jump up and down crazy, and sometimes feel like the car is about to die. Doesn't seem to do it in park.

Mods are: !air, !egr, !A/C, CAI,Transgo shiftkit, running open ypipe. 100 shot ( wasn't on during WOT and driving)

[bennett28]

no one has any ideas?

[Viper]

Change the fuel filter. Slap a pressure guage on it . 35-36PSI idle vacume line on the pressure regulator.
Unhook vacume line psi should be 43.5psi. With line on as engine revs vacume drops so pressure should rise toward 43.5psi. Fuel Pump regulator and injectors working? Berryman B12 Chemtool injector cleaner.
Next

Spark
Spark plug wire tester test the plug wires make sure its wired correctly. Check the spark plugs.
Is the rotor and cap good on the optispark? Start at night and look for voltage leakage from sparkplug wires and ignition components.

Look at Shbox.com test coil ignition module and optispark.

Unplug MAF sensor any difference

Unplug IAT any difference.

Any vacume lines busted? Vacume guage on the egr port vacume normal?

Vacume leak on EGR plates did you use Form a Gasket or High Temp RTV to seal the plates to the
manifold?

Run egr vacume to the switch and block the vacume to the egr valve from the switch. keep the electronic module plugged in. Until you get a tune and have egr/air tuned out.

If it isn't fuel or spark its a sending module or computer error or a shorted wire.

[bennett28]

doublepost :/

[bennett28]

Thanks for the reply, Viper. I already went through everything you have listed, but fuel pressure so far. I should have prolly mentioned what I tried. I'm use to using adjustable fpr's with guages on them, cuz DSM FPRs are so crappy, how are the stock fpr's on the lt1 motors? That will be my next check. Glad when the Spark tester on plugs, wires, coil, opti, etc all was fine. Ran compression test while I was down there messing with plugs and stuff. All 8 around 177ish.

I plugged the egr back up yesterday and it seems to be running a lot smoother and no ses anymore, but I could only take it out for a quick drive before work and today i'm on "baby duty". The rpms still bounced after a wot pull when I was heading back in driving normal, but this time when it bounced the motor didn't bounce rpms with it, just the gauge, but never bounces once it hits WOT, WOT is perfect. Also the volt meter at idle still bounced, but never together. Hoping one was causing the other. Although when I drove it the first time it got bad after 30-40 minutes of driving.

I'm checking alt tomorrow and redoing all grounds on the car, see if it helps. car has high mileage, so could just be an old crappy ground somewhere, hoping. Thanks for the response.

Also I used loctite high temp rtv for the intake and block off plates. I have used it before and haven't had issues with it.

[Viper]

FPR's ok Crane and others make kits to mod them to adjustable but after years of use they develop leaks.
Holley makes a Nice AFPR but costly. 3x as much as the Crane mod kit.

RPM bounce sounds like electrical problems intermittent short possibly or Optispark/ignition module going bad.
Could be a fuse starting to pop but not going all the way out.

Just finished my egr plates with flexible form a gasket. Now have a oil leak to locate on the passenger valve cover side.

[bennett28]

Yea. I'm hoping its a ground, batt, or short somewhere. Took time to get alt tested, was perfect 140 amps. I even took it apart and checked bridge and brushes, all fine. Soooo

[bennett28]

I want to just slap myself silly. I think I found the issue(wont know until rain stops)
I took a razor blade to the charging wire for the alt and the motor mount ground, cut it open and found the only thing that wasn't as green as a lepercon, was the visable wire. The alt wire just poured out green and white. So I get to my wiring and speaker stuff. Got 8 gauge for the charging wire and a nice big ground cable for the mount ground. Hope it works, fingers crossed.