Surging at cruise

[Ei Ei Oh]

Hello everyone! Been lurking for a while, finally decide to join. Here we go so don't roast me too bad.

Like the title says I am experiencing some surging at cruise, not enough to make the car jerk but like a soft hunting idle while your driving. It does it during mid throttle and WOT as well. my wideband is rolling from 13.1 up to 15.7/16.1, back and forth, back and forth consistently and coincides with the surge I'm feeling. Usually the wideband wanders a little bit but doesn't pinball like this at cruise. It started doing the surge yesterday, noticed the wideband dance today. I would assume it's a fuel or MAF issue?

I just did cap & rotor, plug wires, blue top coolant sensor last week, 02 sensor has 600 miles on it. Intake boot is new, valve cover vented to atmosphere. I plan on checking fuel pressure tomorrow...anything thing else I might be overlooking?

Background on the car
1984 eta
600 miles on a fresh rebuild, hone, new crank/con rod bearings and rings
127 DME conforti chip
200 head,
272 reground cam, i valves & dual springs, added oil journals
65mm TB
3 bar fpr
refurbished white top low impedance injectors
cold start valve is deleted

[cheffy30]

pull the icv and blast the fucker with brake cleaner. sent from hell using tapatalk

[Ei Ei Oh]

I got two more in a box, I'll see if they spec out. I thought the icv was just an idle bypass and didn't affect driveability?

[cheffy30]

pull the icv and blast the fucker with brake cleaner. sent from hell using tapatalk

I had similar problems. Cleaning the icv helped everything. sent from hell using tapatalk

[Ei Ei Oh]

I'll check it out. I just cleaned it a week or two ago. I did pull the wires off it this morning and the idle didn't change. It's had a high idle since I bought the car three years ago, nothing has ever worked to bring it down. I changed the icv, green box, dme. So I kludged it last year, that got the idle to get under 1000 rpm.

Remember this is a surge under load though, driving in gear, and I have never seen my AFM bounce in rythm (like a metronome) before. This is the first time I have even had a surge while driving it. I'll start with the icv and check the circuit as well though.

[Ei Ei Oh]

Update. Idle had gotten way worse, doing the 1k-2krpm dance. Found no power to Icv, the valve does open and close when you jump it with 12v. Has continuity from the signal wires to the ICM. No power to ICM box on the #2 wire, box is not powering up when the key is turned on. It will idle correctly if the #2 pin is pulled on the backside of ICM connector and jumped with 12v.

I Ohmed the TPS, idle circuit is open when throttle is closed, remains open when tps "clicks". WOT circuit has continuity at 10° from wot. Going to get another tps from a buddy, the idle circuit is bad on this one. Hopefully the ICM will start getting 12v again with a new TPS installed.