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  #16  
Old 08-07-2022, 04:00 PM
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I had this on a 1996 Express van. Fix was simple yet took forever to find.

The hot wire on the battery, at least on the van, ran from the positive pole to a fuse box sort of thing on the other side of the engine compartment. This was more a box full of fuse able links than a real fuse box. Where the wire connected to this box was a single pole with a nut that screwed down on top to hold the wire.

The nut had come loose and the wire was not making good contact. I removed the wire, cleaned it and the pole, stuck it back together and the trouble vanished.

Hopefully this is all you are dealing with.

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  #17  
Old 08-07-2022, 07:29 PM
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You put your finger on a problem with keeping these old vehicles running. There are all sorts of small items that can become corroded, loose, just less than optimally functional. I’ll look for the thing you speak of.

I found a post from 2015 on another site on this topic, he raised an interesting point that I hadn’t heard before. I’ll cut and paste about half of the post here:

Quote:
From you description, it Seems the 02 sensor is a likely culprit, and hesitation under acceleration is usually a running lean issue.

I have a similar vintage Van, but a Dodge, and my engine power and MPG went up after I cleaned the sensor connectors with Caig Deoxit d5 spray.

The TPS, MAP and 02 sensors, despite their contacts swathed in Dielectric grease their whole lives, had oxidized badly. I used a bunch of Precision Swabs and Caig Deoxit d5 spray to clean the actual contacts.

Flush out the old hard dirty crusty dielectric grease from the connector with a normal, less expensive electronic cleaner product, and then use the Den tek mini bottle brushes to help remove grease. Then spray on the Deoxit d5 spray and work it around with clean mini bottle brushes, and let is dissolve the oxidation for a while.

Then come in with those tiny precision swabs, drug stores might sell something similar for removing make up, and clean the insides of the sockets and the pin exteriors. The swabs will get all tore up at first and turn black. Then less so and turn grey. Use more D5 and swabs until they do not get shredded and remain Pink from the d5. I was using between 3 and 5 swabs per socket before they remained unshredded and pink, and gleamed like oiled chrome.

After I cleaned every sensor contact I could using this method, it felt like I removed 500 LBs from the Van. Around town MPGS I thought forever lost due to taller heavier tires, returned.

My hypothesis is that the computer sends 5 volts out to the sensors, and then makes Air fuel trim and spark timing adjustments on the return voltage from the sensors. When the sensor contacts are all oxidized, too low a voltage returns to the ECM and the AF and timing is not where it should be.
https://www.vanning.com/threads/ubbthreads.php/topics/693506/all/help-with-my-g20-tbi-problems
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1986 300SDL, 362K
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  #18  
Old 08-07-2022, 08:51 PM
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I agree with the cut and paste post. Resistance through loose, dirty and/or damaged connections is FAR from good. Resistance goes up voltage goes down and sensors are sent incorrect values. This can turn into the "snowball effect".

Cleaning and tightening connections takes time but becomes more critical as our vehicles age.

Good luck!!!
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  #19  
Old 08-08-2022, 12:30 AM
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Yeah, that was a lucky find wasn’t it? It’s the kind of thing I wish I’d had the insight to think of myself!

And since we know that fuel and other bits and pieces of the puzzle are allocated at ideally the right amounts at the right time based on those signals, can’t be good if those signals are faulty.
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  #20  
Old 08-09-2022, 01:58 AM
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Holy shiite batpeople. Looks like it might’ve been the fuel filter as the main culprit. INSIDIOUS is clearly wrong about everything else but he was right about the fuel filter.

This has been a weird drama. I limped to the O’Reilly’s by the skin of my teeth when I first had the problem - put in plugs, cap n rotor, cables, and air filter in the parking lot. When I started it up was quite a bit better but not really 100% - the next day it was closer to 100%.

Then, the same drama a week later before I replaced the coil, I wasn’t limping as bad when I got to O’Reillys for that one, but limping. It ran better, but still funny, the next day it seemed almost ideal. Almost.

That was maybe four or five days ago. Today it started doing the missing and hesitation again. So I’m thinking OK, get over the sqeamishness of having gas drip on you, put in the fuel filter. I had a couple of paper towels to catch the dripping, suckers were dirty when I was done. I shook some more of the fuel out of the old filter, holy crap the paper towel got dirty. I’ve not seen that before.

All I can figure is that the tuning upgrade was badly needed and the two steps gave me enough power to fight the plugged filter. Strange.

I’m going to check all the other stuff anyway, the EGR, the idle valve. Going to clean the sensor contacts as recommended by the unknown poster of seven years ago.
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  #21  
Old 08-09-2022, 09:28 AM
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LOL
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  #22  
Old 08-11-2022, 01:19 PM
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Notice we don't hear much about this anymore? He is having too much fun tooling around with trouble free fuel delivery
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  #23  
Old 08-11-2022, 06:30 PM
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Post Periodic Maintenance

I see this all the time : old fuel filters, often never having been changed since the vehicle was new .

My 2000 Ford Ranger Trucklet came to me with the original fuel filter, only 100,000 miles but you should change filters every 10,000 miles or five years as they get restricted and this back pressure kills the electric fuel pumps on modern vehicles .

I know they're not fun to change , Fords require a special tool that fits inside the ring retainer, guaranteed you'll get a gas bath no matter what, why I think so few ever get changed out .

This is one more reason no one wants to work on oldies ~ if you look there's always plenty of "Might As Wells" that need doing and the time alone no one wants to pay for.....

The average garage parts changer / $tealer "Mechanic" only wants to do the quickest flat rate job possible and on any oldie this ensures you'll be going back time after time.....

My brother doesn't like to "waste money" on anything that isn't broken so whenever his jalopy wheezes and rattles to a halt 2,500 miles from home guess who gets stuck fixing it on the road side in Glacier National or Yellowstone park, Death Valley, North Wyoming etc. ? .

Then do I ever get a "thanx Nate "? of course not, only 'that took a long time or wow that co$t a LOT ! " .

If that van isn't rusty and you like it, DON'T SELL IT ON ! .

Replace the little things, U-Joints, drive belts etc. and keep on enjoying your hopefully PAID FOR truck .
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Ignorance is the mother of suspicion and fear is the father

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  #24  
Old 08-12-2022, 02:59 AM
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I paid $1500 for it about 12 years ago, I collected $1900 in insurance for a rounded crease put on one side. So I was on the plus side at that point.

An odd thing with this rig is how many of the bolts are metric. But not all of them. It’s a little bit maddening. Check this out:

The nut Holding the clamp/hanger was clearly metric. So I tried metric for The fuel filter nuts. 17 was too loose, 15 was too tight, am I said, I like many, does not have a 16 mm.

Quickie lesson for anyone We might not know how to transpose these things, not trying to insult anyone’s intelligence, but I was sort of a math whiz:

You only need to remember the number 25.4. Divide millimeters by 25.4 to get inches. Surprisingly that number is accurate to about five places, Here is the actual number:

25.39998

The reverse is to multiply inches by 25.4. Here is a sample problem:

I was curious what the SAE was for 16 mm, maybe I would get lucky. I divided 16 mm by 25.4 and got 0.629921. Multiply that by 16 and you’ll know how many sixteenths you have, in this case: 10.08, which is as accurate as you need. IOW, 5/8 will be too small of a wrench by a tiny amount. Turns out the 5/8 wrench open end would just barely slip over the nut, it was an annoyingly difficult fit at many points.

But my crescent wrench was so huge I’m lucky the 5/8 wrench worked.
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  #25  
Old 08-14-2022, 10:55 AM
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Last time I dealt with one of those wonky fuel filters I came to the conclusion that they were not made for a particular wrench size in either metric or english, but that they were a tweener and you could get some wrench from either set to work even if a tad oversized. Or there was a third system of sizes that I haven't met yet
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  #26  
Old 08-14-2022, 05:12 PM
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I replaced the fuel filter on my Express van as it seemed like the natural problem. It didn't help but it didn't hurt and needed doing.

When running down one of these weird problems you do catch up on a bunch of maintaining you sometimes overlook.
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  #27  
Old 08-14-2022, 07:16 PM
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Quote:
Originally Posted by cmac2012 View Post
I paid $1500 for it about 12 years ago, I collected $1900 in insurance for a rounded crease put on one side. So I was on the plus side at that point.

An odd thing with this rig is how many of the bolts are metric. But not all of them. It’s a little bit maddening. Check this out:

The nut Holding the clamp/hanger was clearly metric. So I tried metric for The fuel filter nuts. 17 was too loose, 15 was too tight, am I said, I like many, does not have a 16 mm.

Quickie lesson for anyone We might not know how to transpose these things, not trying to insult anyone’s intelligence, but I was sort of a math whiz:

You only need to remember the number 25.4. Divide millimeters by 25.4 to get inches. Surprisingly that number is accurate to about five places, Here is the actual number:

25.39998
yea ... NOPE. It really is 25.40. You must have arrived there by doing a reciprocal of an approximation to 0.03937007874015748031496062992126. Or some other sloppy conversion you met somewhere. Didn't your ma warn you about staying away from sloppy? Don't argue. Just accept this. Ask the other engineers if you must. Or open your calculator function. Carry on
Quote:

The reverse is to multiply inches by 25.4. Here is a sample problem:

I was curious what the SAE was for 16 mm, maybe I would get lucky. I divided 16 mm by 25.4 and got 0.629921. Multiply that by 16 and you’ll know how many sixteenths you have, in this case: 10.08, which is as accurate as you need. IOW, 5/8 will be too small of a wrench by a tiny amount. Turns out the 5/8 wrench open end would just barely slip over the nut, it was an annoyingly difficult fit at many points.

But my crescent wrench was so huge I’m lucky the 5/8 wrench worked.
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  #28  
Old 08-14-2022, 07:32 PM
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Smile Mathmatics.....

I told him to take off his shoes, that mostly works for me.....
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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better
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  #29  
Old 08-15-2022, 04:37 PM
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Any maintenance done yourself that reduces the chance of a road breakdown. Tends to be cheap in comparison. Or extends the useful lifespan of a vehicle.

I really go over an older vehicle before putting it in service.
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  #30  
Old 08-16-2022, 01:22 PM
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Quote:
Originally Posted by INSIDIOUS View Post
yea ... NOPE. It really is 25.40. You must have arrived there by doing a reciprocal of an approximation to 0.03937007874015748031496062992126. Or some other sloppy conversion you met somewhere. Didn't your ma warn you about staying away from sloppy? Don't argue. Just accept this. Ask the other engineers if you must. Or open your calculator function. Carry on
Bad news chief. 25.39998 and 25.40 are essentially the same number.

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