Ben and I went back to work on the Yellow Peril. Now early last week it was running fine. Then it got to not idling and then it was too rich,
spark plugs dripping gasoline and no start no matter what. Spark and timing
fine. Today we pulled the computer, unplugged it and traced the wires to the
coolant temp sensor and the thermal timer. Coolant temp sensor connectors at
the computer had about 2500 ohms between them, which is what it should be.
No continuity with the thermal timer. Got clicks when opening the throttle
like it is supposed to do. Put it back together and tried to start-
wouldn't fire. Pulled a plug and it was bone dry so I sprayed some starting
fluid into the manifold and it hit a few licks and quit. Hooked up the fuel
pressure gauge and it was holding 30 psi. Tried adjusting the manifold pressure
sensor richer by steps checking the plugs each time to make sure we had not
flooded it. We could get it to fire a few times but never start. We got the
screw out as far as it would go in the manifold pressure sensor and it was still
doing the same. I cleaned up the dirty, slightly corroded computer and it
didn't look like anything was broken or corroded through so I put it in.
No change. I tried the other nonleaking manifold pressure sensor. Still no
change. So with either MAP sensor or either computer and any adjustment on the
MAP sensor, it is still apparently too lean. I tried disconnecting the leads
to the coolant temp sensor, which should make its resistance infinite and it
should thus make the mixture full rich. Still have cold, dry spark plugs.

I do have a different computer on the way but am still looking for a good
Manifold Air Pressure sensor for a D-jet system for a reasonable price.
Can any of you give me any suggestions? Wonder if the Lord is using this as
a "thorn in the flesh" like He did the apostle Paul.........

To test that the fuel pump is pumping at the appropriate times you can disconnect the main lead at the starter and turn the key to Start. Pump should run continuously until the ley is released.

To test the function of the trigger contacts pull the little tray out of the bottom of the dizzy, leaving the wires in place. Pull the injector rack and set it on top of the motor with paper towels underneath. Turn the key to On and work the contacts with your fingers. Doing so should pulse the injectors as well as make the pump run briefly.

Anyway, just a couple thought. Hope it helps.
--
Justin 66 122E
Read vclassics tech!

George. My old tech teacher used to say EARTHS, EARTHS, EARTHS. If they are bad what you think is going in isn,t. I cant imagine the Lord being so cruel to you more likely Murphy followed your ancentry to the US and its payback for leaving Ireland.

Benjamin Downs DID come from Ireland......
BTW we gringos call them "grounds" as we try to keep the earth/soil washed
off the electrical connections. Probably "chassis connection" or
"chassis common bus" would be a better term, and even more confusing.

If other suggestions don't fix your problem it might be worth looking at the relay(s). Fit a temporary jump wire between the battery positive and the fuel pump feed so that the pump runs continuously, regardless of ignition key position. If the engine starts and runs then it could be worth checking the wiring to and from the relay(s) or the relay(s) themselves.

Right now the fuel pump is on the wiper circuit. (That's the way it came
to me.) Mostly the fuel pressure (by pressure gauge) seems to be OK,
although sometimes it takes a dive during cranking. Might even be in
the ignition switch.

I think I have an old set of totally worn out SUs in the basement. They will probably work better than what you have now....(he he). I can't help rassing you a bit, especially as I know that for you the easy route would be to use carbs, that being said I totally understand that with Volvos they are so reliable it's fun to have a challenge once in a while and with a D-jet setup you will definetly be challenged.
The only thing I can suggest is to post questions at the BB 1800 forum or maybe another site for 1800 as those guys seem to know D-jet better than most.
--
Patrick, '68 220, '83 245, '92 Eurovan (work truck).

Gosh, Thanks, Pat.

I have 2 extra pairs of HIF6s and no telling how many HS6s. But I want to
do THIS one RIGHT. I think I have some good ideas now.

Are you on the way from northeast Vermont to Nova Scotia? Next time I get
a lot of money I have dreams of tripping up that way to visit Volvo folks,
listen to fiddlers, etc. An associate in NS has offered me a bed up there
for a few days and being of Scottish/Irish descent I have sort of a natural
leaning in that direction (in SUMMER only....)

Would you believe I backrobbed the gray wagon (the one with snazzy leather
upholstery) for a radiator for the ugly celery wagon? I had an 1800 radiator
but couldn't use it because the mounts face the wrong way putting it about
1" into the fan with no spacer. The other wagon's radiator cracked below
the outlet fitting at the bottom and was staining the driveway, endangering
the engine, etc. Guy at the radiator shop says 2 days. I didn't ask about
$$.

Keep warm and dry. (I'm warm enough but I really need to change shoes/socks
after going to the store in the rain - we got over ½" so far today. The way
it has been here lately you'd think we were in O'Regon or somewhere like that!)

Ummmm Soooo Now I'm an "Associate" Hmmmmm And all this time I thought I was just the Gullible Nova Scotia Hotellier ....... ;-)

let us kinow when you are coming and we'll swamp out the bedroom for you and the Missus ..... might even change the sheets for you ... well at least for your better half ....

Brett
--
Brett Sutherland & the 1.5 million mile 122 CANADIAN www.ecvintagevolvo.com

Trigger contacts George? They form the injection pulse. Maybe you have seen to them previously.....maybe the connector fell off, or they are dirty. A special tool is required to set the gap, or gut an old distributor to see the gap and set to .015.
Rhys

I had checked and cleaned them before but not lately. That seems
to be a great suggestion and as soon as the rain stops we'll
czech it out.

Many thanks!

You can unplug the harness from it and check for "make-and-break" with your ohm meter while cranking the engine over. There are three contact pins - the center pin is common to both breakers, so you want to check for continuity across the center and right side, then check center and left side.