RE "Eventually the whole length shown below disappered into the port in the direction of the exhaust and the brake fluid drained away so I'd guess it cleared the blockage." above, anyone know where exactly that goes?

Can only find generalised "How an EGR system works" stylee diagrams.

If its into the actual exhaust, that should be OK, but if the fluid could drain into a cylinder, hydrolock might be a possibility and I'd better take the plugs out. There was about 20 mls of fluid.

No response from 3 US-based Accord forums apart from some guy insisting I had a diesel engine. The Internyet at its best.

Proceeding independantly

cimg7.ibsrv.net/gimg/honda-tech.com-vbulletin/600x...g

Looks a bit close. so to avoid the (probably unlikely but dangerous) hydrolock possibility I turned it over with the plugs out.Plug out turnover is essentially the same as for a compression test without the compression tester.

This guy

youtu.be/Pu96PSxxH7Y

Pulls a couple of 15 amp fuzes to disable FI and Ign on his 1998 4 cyl VTEC, box drivers side footwell, RHS top and bottom.

COULD NOT find fuse diagram in 98-2002 FSM, nor that fuse box on this car

ETCG, on what looks like an earlier Accord but is a generic how-to video, disconnects the distributor and floors the accelerator, to put it in "clear-flood mode", so I did that.

youtu.be/X_tbksFYhl4

Plugs look pretty good (though I'm used to old carbed vehicles). Certainly don't reflect the Land of Mordor vibe of the intake path.

cimg4.ibsrv.net/gimg/honda-tech.com-vbulletin/1297...g

Maybe the bit of staining on the porcelain margin is a contra-indication though.

cimg3.ibsrv.net/gimg/honda-tech.com-vbulletin/1297...g

On turnover (3X5 second bursts) there was a noticable smell of petrol, so it seems Eric's Clear Flood Mode ain't always so.

I would have predicted Honda would have engineered the system so cleaning it wouldn't dump muck in the cylinders, and I would have been wrong. Glad I took the precaution. Almost didn't

cimg4.ibsrv.net/gimg/honda-tech.com-vbulletin/1297...g

Dunno whether #4 cylinder is closest to the ERG port, or it just happened to have an open (or leaky?) exhaust valve.

Of course I used brake fluid, which is a very effective cleaner but non volatile, whereas carb cleaner etc would probably evaporate quite quickly even from inside a cylinder.

I found some info on the valve pins so I'll test that later. Time to burn some brake fluid.

cimg1.ibsrv.net/gimg/honda-tech.com-vbulletin/1297...g

Oo-er!

Probably not promoting catalyst happiness.

(I've never had a catalyst before. They seem to be a b***** nuisance)

Settled down after a bit of a drive. Seemed to drive slightly worse but still OK. If its no good I'll blank it off and presumably be back where I started.

Edited by edlithgow on 02/08/2020 at 14:28

Partly answering my own original question

EGR valve has a 5-pin connector, 3 on the top,(1, 2,3) 2 on the bottom, with a gap in the middle (4,x, 6)

Seems resistance 1 to 2 and 1 to 3 should be < 100Kohms (dunno what the actual readings should be though)

1 to 2 is 1654 ohms, 1 to 3 is 4300 ohms, so in range, if I''m reading it right.

4+6 power the pintle solenoid 4 bat +, 6 bat -

Jumpering these to battery gives a solenoid clicky sort of noise.

Doing it with an idling engine makes the engine stumble, implying my perilous partial clean of the EGR path is sufficient to mainline muck into the engine as designed, though it would have been better to have tried this before cleaning as well, to have a comparision.

Further testing would probably require looking at the computer side, and I'm not doing that.

After leaving the battery disconnected overnight (to clear the CEL) anjd doing the above EGR valve testing I STILL have a CEL code 80 (EGR insufficient flow). so either the clean didnt fix it or a minute or two at idle with a disconnected EGR is sufficient to reset the code.

Is it?

I've disconnected the battery and will see if I still have the code tommorrow.