'88 Raider -- What the...?

New member here. Just picked up an '88 Raider. It is not running right at all. Starts and seems okay at idle, but any rpm above that it starts to backfire and diesels on shutdown. I bought a factory service manual, read through some of the FAQs and have already picked up most of the stuff on the "Do this first" list. Pulled the plugs - 1 and 2 were fouled and sooty, 3 seemed only slightly lean and 4 seemed okay (but maybe had a bit of rust on it?). The sort of rusty look and the fact that the radiator was 2 qts low on coolant makes me a little worried that there might be a blown head gasket or other sort of coolant leak. I didn't see or smell any coolant and didn't see any coolant in the oil or vice versa.

My other questions are about the vacuum tubing, etc. It has a Weber and a lot of the vac tubes are cut/plugged and the ports are capped. So here are a few pics with the questions -- does this look right? and what should I do about this (if anything)?

Here's the carb. Looks there is a fuel line going into the fuel pump and then the carb inlet. It looks like the other line out of the pump has been cut and both ends plugged. Should this vent back to the tank?

http://i1111.photobucket.com/albums/...psf3c012a2.jpg


This is the box that contains the vacuum switch, the secondary air control solenoid valve and the vacuum relay. It looks like everything here has been capped off except the line coming in from the EGR valve. Does this look right for the current carb setup? I don't think the engine is using anything in this box anymore, so my gut says it's okay.

http://i1111.photobucket.com/albums/...ps40c99344.jpg

Which brings us to the EGR valve. It has a hose going in on the top and a bigger hose going out on the bottom, which goes to the box pictured above. I don't think this is being used anymore either. Can I just cap both of these ports off? Should I spray any kind of lube in there to make sure the valve doesn't get locked open or closed before I do?

http://i1111.photobucket.com/albums/...ps1ab11397.jpg

That's it for now. If there is a thread I missed or keywords I should use in my search let me know. More questions and pictures to follow. Thanks in advance for any answers and advice.

The EGR valve should have lines connected to a thermosensor on the intake manifold near the distributor or thermostat area. The second line from the pump is a vapor return line that is part of the Mikuni carb setup. Most of the threads I see with Weber carbs also limit the fuel pressure to 4 psi. Also, backfiring could be a timing related issue.

Lastly, look into the search function on 4x4wire.com and research the issue there. This is an often discussed topic with the Montero crowd, too.

Quote:

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Originally Posted by rxinhed

The second line from the pump is a vapor return line that is part of the Mikuni carb setup.

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The second line is the fuel feed to the accelerator enrichment pump on the Mikuni carby. You'll have to determine if the EGR valve is still functioning and has a vacuum line connected to it that is supplying vacuum. The EGR valve will stay shut until vacuum is applied to it (but these things are notorious for carboning up and most of them are non functioning...) The EGR gallery either blocks from inside the head, the gallery through the inlet manifold gets choked off or the EGR valve blocks up - or a combination of the aforementioned.