My 1973 1800es is losing power when the tank is about 1/2 to 1/4 full. The engine starts to stall and I feel like it’s probably something in the fuel system. I’m going to clean out the tank and replace the fuel filter, but is there any other things that could be causing this? Also, has anyone had good luck cleaning out their old gas tank? My car has been in Southern California most of the time, so I’m hoping the tank will be okay after some cleaning, but is the interior coating that some radiator shops provide a good idea for the 1800’s gas tank? Thanks!

Draining the tank and replacing the fuel filter is a good plan. What comes out with the gas may give you an indication as to whether you need to go further. If the gas has little residue / evidence of rust then there may be no need for further remediation.

A fuel pressure test is the definitive way to evaluate fuel starvation. I think a '73 D jet would run with a rail pressure of 30 psi. Arranging the test so that you can drive the car can be a little tricky. I did this once on my B20E by using an oil pressure gauge, flex nylon tubing and some brass fittings to tap into the cold start valve line. I duct taped the gauge to the cowl in front of the windshield so I could watch the pressure while I did a couple of full throttle shifts up to about 100 kph. If the pressure holds steady; but, you are loosing power then the problem is something other than fuel supply. If you see the pressure drop at the same time as you have power loss, then you know you have a fuel supply problem.

Your problem can also be caused by a tired fuel pump. If the pump is getting tired, the increased suction head requirement caused by a drop in fuel level in the tank can result in loss of flow and low pressure (remember the D jet pump is not a submerged pump like modern cars).

I did the POR treatment on my 142 B20 E gas tank. 10 years since I did the treatment and no issues have emerged. However, I cut large holes in the roof of the tank so that I could media blast the interior of the tank and then patched those holes with the top of a donor tank from a non D jet car (there were no reproduction tanks for 140 D jet equipped cars). I then did the degrease and acid treatment before applying the coat. A fair amount of work. If repro tanks had been available I would have gone that route.

Thanks for the information, that's very helpful! I took out the fuel sender and it looks really clean in there, I need to get the proper tool to take off the brass plug and check the primary fuel filter - maybe it is the problem? If not, looks like I'll be moving on to checking the pump and the regular fuel filter.

By the way - do you know the proper tool to remove the brass plug at the bottom of the tank? I think last time I took one out I found a bar of steel that fit diagonally across the square hole and turned it with a crescent wrench, but the one in my current car is already a bit mangled and I don't want to make it worse.

Its been a long time since I removed that plug; but, like VOTX I seem to recall using a 3/8 drive on my 140. Some of the D jet equipped cars have a filter sock on the suction.

http://212.247.61.152/us/main.aspx?page=article&artno=688593

My 1971 142 has one. I can't remember whether the sock was an add on after the first run of D jet cars or got deleted on the later cars. Check to see if your car should have one. If so, purchase a replacement before you do the drain because it will almost certainly have disintegrated or be plugged. Saves you having to drain the tank twice. You will have to go to one of the vintage Volvo specialists to get one.

I usually have the intank filters in stock.

The access plug for the stock intank filter has an odd sized square recess form removing. I made my own tool by grinding a short 1/2" extension to fit.

And on another subject, it appears Fran is looking for a tail housing for an 1985 Volvo automatic transmission and I might have 1.

Please give me a call if interested at:

tree 1 ohh 5 tree tree ohh to 7 1


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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

So, larger than 3/8"; but, less than 1/2"?

Yes, I get the sense that it's about a 10mm square but mine is currently too beat for me to get out the micrometer ;)

Not sure what size your plug is, but I have used the square end of an extension in a breaker bar, or ratchet on similar plugs on my old tractors etc.

The pick up tube inside the gas tank may have holes and when the level in the gas tank gets low enough, it starts sucking air.

Most radiator shops can replace the pick up tube.

If your tank does need to be coated, there are 2 basic processes, air cured and heat cured.

There are several air cured types, but in my experience, they don't last very long and that's usually due to the lack of complete rust elimination.

The only heat cured process that I know and I recommend is called ReNu. The process involves removing all the rusty metal inside and outside of the gas tank by sandblasting. All rust holes and thin metal are patched or replaced. Then the inside and outside are coated and then heat cured in an oven. The process has a lifetime warranty.

You can buy a reproduction gas tank for less than the cost to ReNu, but the warranty for the repros is only for a year.

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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Thanks, Eric! I'm going to be siphoning out my tank tomorrow and looking inside to see the condition. If it's pretty clean I'll just have a radiator shop flush it out, but if it looks like it needs to be coated, would you have any shop recommendations? I'm in your area (I'm over by Dodger Stadium) and I couldn't find any places with the ReNu technique that have good reviews. Thanks!

AFAIK, there is only 1 ReNu shop in all of Southern California, Orozco's in Bellflower.

They ain't cheap, but the ReNu process does come with a lifetime warranty.

What did you see online about them?

I went to Yelp and found good and bad reviews, but nothing about their ReNu service.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502

Oh, I just saw some positive and some negative reviews, and then no mention of the ReNu process in any of the reviews, so I was cautious. Is that the shop you used on your tank?