I've talked about mpg issues and a stumbling problem (fixed) in previous posts on my '72 145E. My mileage is still not what it should be, though improving. Last fillup was 16mpg, and the next one should be a bit better. I checked my fuel pressure last night and it was a little high, 32psi. The regulator adjusted down fine to 28psi. Turning it down produced a barely perceptible hiccup off the line.

I checked the resistance at the coolant temp sensor, a few minutes after I turned the car off. It was at 380ohms. Isn't it supposed to read under 100 while at operating temperature? If there is too much resistance in it, would that cause a rich or lean running condition? From what I've read, I'm inclined to say rich, but that doesn't seem to jive with what else is going on.

I have to leave air temp sensor unplugged to get a decent idle (especially cold) and off the line performance. Unless I'm mistaken, this should cause d-jet to richen the mixture. I feel like I should be running super rich right now, but it doesn't feel (or smell) like I am. I wish I had a wideband 02 sensor...

Anyway, I'm kind of confused. I'm inclined to replace the coolant temp sensor and see where that takes me. I also scored a fairly cheap and supposedly "known good" MPS off ebay, so I'll be testing that out as well.

So my question is, does any of this resonate? After reading some archived posts and seeing stories of 25+mpg highway with the aw35, I'm kind of obsessed with getting north of 20mpg at the very least even though I'm still planning the m41/t5 conversion.

Sorry to be so... verbose.

You can get what you need out of D-Jet with MPS adjustment. The only limitations are that you are limited to about 150HP & you need to stay with a cam that has an inlet lobe with the same duration as the D cam does. D-Jet can equal MegaSquirt economy too, the only real problem with D-Jet is parts & if you have to buy parts, then you're better off putting that money towards MegaSquirt or Twin 45mm DCOE's.

Rip it out by its scrawny frayed ECU box and wiring harness.....replace with MSII.

The only thing a wideband O2 sensor can do with D-jet is tell how bad it is doing. Get the WBS hooked up, then go for perfect ecomony and or tuning with Megasquirt. It really will feed your obsesion for getting the most out of your engine.
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Antique Swedish Steel 71 142E color V#102

I'd definitely like to do this. You're right in that I am obsessed enough to want to get the most out of this setup, and I know that won't be accomplished with d-jet. It's just not in the budget, likely not until next year anyway.

Yes, it's great but will set you back at least $500.00.

Getting the D-jet working properly is easy if your parts and sensors are in good shape. Test the d-jet out, the MS still requires some working sensors to work.

Try the Megasquirt conversion when your MAP sensor dies - then it'll be worth the money.

Try the Megasquirt conversion when your MAP sensor dies - then it'll be worth the money.

Except I just picked up a spare one of those for $30 :) So, two MAP sensors in the future, MS will be mine!! Hah, that is exactly how I was thinking about it though. I know MS will be a "learning experience", for sure. I also don't know that I'd attempt it while I'm still relying on the 145 to get to work.

yeah, I've got a spare one too. The economy needs to get better before I plunk down the cash for an MS conversion.

Just went thru this, the ecu thinks it is 32 below,
and is enrichening the mixture accordingly.
let me guess..15 mpg?
I vote with Jack put a new harness on the coolant temp sensor first.
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71-145-S

Actually, you're pretty close on the mileage. If I'm still having issues after I sort out the #1 fuel injector, this is the next way I'm going. Hell, I may just check it out since I'll probably have some down time if I get the injectors cleaned.

"...Turning it down produced a barely perceptible hiccup off the line...."

It may be a dirty or worn throttle position switch, which also acts as a sort of "accelerator pump" in the d-jet system, and possibly the high pressure regulator setting was compensating for it??? (I'm reaching here.)

Also, how about the ignition components. Years ago I had a 72 144 d-jet and I found that plug wires seemed to fail more often than the plugs, points, condensor, or cap.

How does it idle?

You might also pull one plug wire at a time while it's idling and look for a weak cylinder.

Possibly a burnt valve?? How's the compression?

Just some food for thought. Good luck with it.

I pulled the plug wire, no noticeable change in idle. Pulled the wires on 2-4, definite change in idle. Swapped another wire in on #1, no change. I just changed the plugs, so I know it's gapped right. And it's new, so it should be working.

Pulled the fuel injector wire, no change. Went down the row, all the other injectors being off produced a change in idle. Boy, I hope it's that fuel injector. Time to get a compression tester...

have you changed your cap, rotor, and points lately?

If you have a timing light (get a cheap one for ~$12.00 at Harbor Freight if you don't) and confirm an ignition pulse between the coil, cap, and four spark wires.

if that checks out check the injector function. It should return around 3 ohms of resistance. confirming Actual squirt function is more troublesome.

It's a bit risky (take precautions against fire) but you can remove the spark plug from your cylinder and give the engine a quick crank. If the injector is firing you'll see a squirt of HIGHLY FLAMMABLE air/fuel shoot out of the plug hole.

Seriously, be VERY careful if you do this, I sparked a small fire on the side of my block because I forgot to disconnect the coil.

Still it's dead proof that you injector is working...

Yes, I've changed all of them in the last month.

I have a timing light, and the engine is currently timed off the #1 plugwire. I haven't checked the others, though. I'll try them tonight.

I'll also check the injectors... I may just pull the injector and aim it into a container, and plug the hole in the head. Or your method. We'll see. If yall don't hear from me in a couple days... Send help. Hah!

I did some testing while I was out and about a while ago. Definitely about 3ohms resistance on the injector. Also, there is a noticeable different if I leave the injector unplugged and try to drive around. The car still moves, it's just a bit more sluggish. I'm guessing it's partially plugged? I'm going to pull the rail with all the injectors and have them cleaned on Monday.

Ended up buying a used injector on my way home, guaranteed working... No difference, at idle anyway. I can still unplug both that and the sparkplug at idle with no difference. Just ordered a compression tester...

The entire site is behaving a bit goofy at the moment. I sometimes get a "cannot find" error when I try "www.brickboard.com". If I add "/RWD/" to the domain name it pops right up.

The AWD and the OPINIONS navigation on the right seem to be gone for now. You can get to either using the dropdown menu (select shortcut) at the upper right corner of every page.

--sd

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Mr. Shannon DeWolfe -- I've taken to using mister because my name misleads folks on the WWW. I am a 52 year old fat man. ;-)

Someone previously mentioned the throttle switch in another post, which prompted me to open it up and clean it. There were no obvious signs of faulting. I know the regulator was compensating for something, though. I think the djet fault tracing document will really help me get to the bottom of that.

I've replaced the points, condensor, cap, rotor, and plugs in the last month. That's a good call to check the wires, I'll have to do that.

When it's warm, it idles well. I discovered this morning in about 40 degree weather that it's back to not idling well at all when cold. It died about 2 seconds after the first start. After the second start I kept my foot on the gas and let it run around 2k rpms for 20 seconds. After that it would idle, albeit grumpily. The aux air valve still isn't working, it seems. I pulled it off last week and soaked the insides in PB Blaster for a few minutes, but that didn't seem to produce much of an effect.

I have been wanting to check compression, but two things have held me back.... A) I'm scared to, and B) I don't have a tester right now.

Hey, I just got the D-Jet going in my 1967 122S Wagon (FI system is from a 1971 1800E)

I experienced horrible performance because the wires from my #2 temp sensor (coolant) the computer were broken and frayed. I had to take the spades out, clip the wire back to good insulation, then resolder the spades (difficult and required patience) but the end result is an engine that runs well. The car's far from being roadworthy, so I don't know about the mileage yet.

I *high* recommend you look over this document
Volvo Fuel Injection (D-Jet) Fault Tracing
I used it to test my system. It's set up like an species identification key - if you've ever used one of those.

Since you have an Automatic, this one might be useful too.

Cheers, this will come in handy if I ever get my 142e back together.