Searched archives, there are no results. This is not an ordinary issue.

'94 B18C1, C5 cams are set at +8 deg, stock P72 ECU.
Idle steady @ 800 RPM, ignition timing perfect, IACV is new and working, but:

At any speed/ gear, as soon as I close the throttle, the revs drop past idle and dog at 200 RPM for about 1 second, then return to steady idle.

I lose ~100 RPM with headlights on, no compensation.
When cruising at <5 degrees open throttle in any gear and suddenly accelerate, it misfires.
??

 

I have a da that did this.. i know it sounds nuts but i changed my battery and terminal ends and it fixed it. They were really corroded bad.
I also have a dc that did something like this bc of a blown head gasket. It didn't react to the headlights though like my da did. So try the battery and ends thing. Good luck

 

Just rebuilt the entire motor about a month ago, new head gasket included (actually every gasket is new), same symptoms.
I installed a ground kit with new terminals, and six grounds to the chassis & engine.
All the sensors are brand new, O2, MAP, IAT, ECT, knock.

Stock ignition, stock harness, new spark wires, new dist cap, new main relay.
The in-line fuel pressure gauge reads in spec, air/fuel is stoic & steady, filter has <3000mi.

The vacuum reading is low by ~1psi all around, but nothing on the intake side is stock, and low vac just increases fuel delivery. EVAP system is new & functional.

I'm out of ideas.

 

Try a friends battery. A weak battery willwill cause this too.

 

Brand new Optima Gold.
But from what it sounds, everyone's pointing toward an electrical issue.
Is it possibly the ELD? What's a good way to check it?

 

Im out of ideas.

 

yeah, it's a tough one.
anyone else?

 

Charge the new battery good. Don't let the alternator struggle trying to bring it up!!! Check battery cables and connectors. Its easy to think connectors are clean when really they have a grey residue on the inside. Are you running a heavy duty stereo??

 

Why is the cam timing set to +8°? Did you use the correct timing mark (white) on the crank pulley to find TDC (white is right)?

 

It's ported with a short runner large plenum manifold, oversize TB and a Type R header, who wouldn't advance the cams?

Yep, 16° BTDC with idle at 750 RPM, according to the timing marker line on the belt cover, ~20° counterclockwise of right angle from the crank.

300-watt 10" sub & component speakers (Del Sol), nothing heavy. I disconnected it for 3 days, no change.
Had the battery charged and tested locally a week ago while cleaning the terminals, which I coated with a de-ox.

I'm really apprehensive about having to pin-out the ECU for problems, if we can narrow this down I'd be extremely grateful. PS thanks for all your suggestions so far.

 

I forgot to mention, after the idle almost dies, it over-revs to about 1100 RPM for a second before settling.
I turned up the idle to about 900 and it does the same thing, just respectively higher.

 

test the alt.

 

ok. from everyone's responses it most definitely seems like a power supply issue, so I'll test the alternator, check the ELD, run a resistance check, and swap my distributor out if all else fails.
Thanks a **** ton boys, ciao