Help! Having trouble with my 83 wagon

[Midnightz]

I replaced air filter, oil, fuel filter and primed. The wagon could start, idles fine for about a few second when cold, then slowly idles rough till dies. If I try to start again, it would idle very rough and die in a second or two. If I stop and come back in about ten minutes or so, the sympton would start again with good idle for a few second. I always wait for the second "click" before I crank. If this was a carburated car, I would think I flooded it...

From searching in this forum, I am thinking this is glow plugs or injection pump related. But the temp out today in Seattle is about 60 and since it'll idle, it would be unlikely due to GP, right?

I am not comfortable with tinkering with IP or doing a IP timing at this point. If IP is the most likely cause, I would take it to a shop. Could anyone reconment a shop near Woodinville area who's knowledgeable with LD28?

Anythingelse I should also check?

TIA

[asavage]

If this is a new symptom after replacing those items, that sure sounds like fuel supply to me. The LD28 doesn't have the same cold misfire GP problem that the SD seems to. Both of my LD28s come up rough and smooth out (takes longer on B99 biodiesel though, to smooth out).

If yours will gradually die off, I'd recheck that the fuel supply is completely bled of air.

Less likely is that the afterglow circuit isn't working. Afterglow is the lower-power supply to the GPs after you hear the loud thunk of the main GP relay dropping out. Matt says it also afterglows during cranking. I've never seen a problem with the afterglow system, but it should be straightforward to check.

But I still think you should look for air in the fuel supply first.

[Midnightz]

The rough idle was happening before I did the work and I thought a new fuel filter would cure it. I used siphon pump to prime the new filter, after I got tired of using the little "button". Would the siphon pump creat too much air bubble?

The engine would die faster if I give some gas to try to keep the idle up. I could move the car a few feet in the few second I had with good idle.

Is pumping the little button the best way to bleed the air?

TIA, again.

[diesel-man]

Possibly the best place to start ( like going to the Doctor) is how did the problem first begin? From when it was fine, until now.

Is the problem only when it idles? How did it run above idle, previously? How long?

It is most likely an air problem. Yes, it is best to use the "button" (as you put it) on top of the fuel filter. Did you have the air bleed screw out while you pumped it? Then replace screw, pump it twenty five more times, just because.

A lot of suggestions could be raised, if this or that. No need to be short and concise.
Wayne

[asavage]

A thought: are you now, or have you ever, used an "alternative homebrew" fuel in this vehicle? I had a lot of issues after a very bad batch of biodiesel was delivered by our then distributor two years ago.

[Midnightz]

Thanks for your help, Al and Wayne,

This is the first time I got to work on it after I bought it last November. The seller said that the engine ran well, but had transmission problems. Didn't get the impression that he used biodiesel or any kind of alternative fuel. The tank was almost empty, but I put in a gallon of D2 before I try to start it.

It appeared that it was the air problem. After reading your responses, I went out again last night to pump some more. Boy, I wish the stroke of that priming pump was longer I was about to give up after pumping the "button" for what seemed like a thousand times... all kind of thoughts came to my mind: is the priming pump working? maybe somehow the priming pump is flooding the engine? maybe there's a fuel leak, maybe I should leave the vent screw just half way out, I really wish the stroke is longer... Then I realized that when I siphoned the filter earlier, I should have siphoned it at the return hose! Duh!

So, after a few strokes with siphon pump at the return hose, I have a steady idle and I can rev it up! Whoo-hoo

The next thing to look at are the rear brakes before taking a test drive. I am not getting any pressure at the pedal, even after bleeding the front brakes (Did that when the front end was on the stands). When I press the pedal (to the floor), the BRAKE light would slowly light up like it's low on fluid... Any thoughts?

BTW, while I was under the car earlier looking for fuel leak, I also looked for transmission vacuum leak similar to this post. I found that at the aft end of the metal vacuum line, a rubber hose was torn. Hopfully, that's the cause of the transmission problem that the previous owner had.

Paul

[asavage]

The next thing to look at are the rear brakes before taking a test drive. I am not getting any pressure at the pedal, even after bleeding the front brakes (Did that when the front end was on the stands). When I press the pedal (to the floor), the BRAKE light would slowly light up like it's low on fluid... Any thoughts?

If the brake warning light comes on when you press the pedal, that's the pressure differential valve warning that the hydraulic pressure is higher in one circuit than another (front vs. rear). Bleed the rears, that's what leaks when the car sits (residual pressure of about 2 PSI is required for wheel cylinders to maintain their seal. Let it sit, the pressure goes away, and the fluid leaks out).

The brakes are marginal for the size of the Wagon, so you want to make sure it's all in tip-top condition. And the rear brakes do not self-adjust except when you operate the parking brake, it's true. They will not self-adjust by reversing and applying the service brake, like most cars.

1983 (only) has a low vacuum switch on the brake booster that can light the same brake warning light if you lose vacuum (say, the alternator belt breaks, or you have a large hose leak). If you had a very bad brake booster, applying the pedal could drop the vacuum enough to trigger that switch, but even on a diesel I'd think you could hear the vacuum hiss. Just mentioning the possibility; air in the rear hydraulic circuit is by far more likely.

[Midnightz]

Ok, I am at a complete loss. It appeard that I am still having some kind of fuel supply problem.

After parking the wagon for a couple of weeks to pull parts off the parts wagon, I couldn't drive the wagon out of the driveway, again. Siphoned again at the return line, had good idle again, drive up the street, died after about 100 yards.

There is no fuel pump in the tank, right? Does running out of the fuel after about 100 yards means that I have depleted the fuel in the IP and the fuel filter and IP is not drawing fuel from the tank?

Back pumping again at the return line. I had clear vynil tube on the siphon pump so I was able to see what's coming through. The interesting thing was that as I draw the fuel out from the return line, the fuel would recede back toward the IP... even below the level where the vent hole is on the priming pump. I figured that the priming pump is the highest point of the fuel system and I expected that I should be able to draw the fuel out of the return line at or just below the level of the vent hole. At first, I thought maybe the fuel is receding back because there are so much air bubble, but I pumped and watched the fuel recede for a few times and the rate of the recede didn’t seemed to have changed.

Any thoughts on why I am not having a steady supply of the fuel and why I am not able to “fill the IP with fuel”…

[goglio704]

Sounds like an air leak to me.

There is no pump in the tank, but there may be a strainer of some sort? A sock on the pickup tube perhaps? I don't know. If there is a sock and if it is restricted, that could make it easier to draw air than fuel.

On a suction system it is possible to suck air in through a leak which doesn't let fuel out.

Have you opened the fuel cap to see if the tank is developing a vacuum? If it is you should see an improvement by leaving the cap cracked open. I would think this tank would be vented to atmosphere.

[asavage]

The interesting thing was that as I draw the fuel out from the return line, the fuel would recede back toward the IP...

I'll bet $10 that you have a fuel supply restriction.

You've already replaced the fuel filter. On the Maxima, there is only one (unlike the 720). Stop guessing and buy a tee and a vacuum/pressure gauge and tee it into the IP supply line:



Duct tape it to the windscreen. You should never see greater vacuum than about 2" maximum. I bet you'll see it go way below that.

See also this fuel supply story.

The lift pump on the Bosch VE IP is integrated into the IP -- it's a vane pump and cannot be serviced separately from the rest of the IP, and is actually harder to get to than the distributor head. It also hates dirty fuel. Its correct operation is absolutely critical to the timing advancing mechanism in the VE -- an external lift pump will not work to replace a failed VE internal lift pump, the timing will never advance correctly, forget it.

And don't even think about adding an external electric fuel pump until you diagnose the inlet side.

Once you determine that you have too much "suck" at the IP inlet, move the gauge to the inlet of the fuel filter and repeat test.

You might have something restricting fuel in the fuel tank, a crushed steel line, a plugged steel line, or a collapsing flexible line. I have seen ALL of these over the years, in addition to the punchline to the story linked above.

[I once had a friend's '70 Nova to diagnose. You could drive it around the block -- maybe -- but any faster and it was fuel starved. It had a pinhole rust-out on a steel line. Get this: it did not leak fuel. But it would pull air (sound familiar, ecomike? And fuel is much thinner than coolant.). Found it by pressurizing the steel line and tank to 2 PSI, and then it would leak -- do not try this at home! Talk about obscure!]

[goglio704]

I've done some research and have a theory. There is a rare condition where non rusty 83 Maxima diesel wagons simply won't run west of the Mississippi river. The cure, obviously, is to relocate them east of the Mississippi - preferably to Tennessee.

[diesel-man]

Take up the rug over top of the fuel tank, take off the inspection plate and check for a rusty line on the fuel tank guage. Maybe rusted near off?

I just went through a crazy problem that took a year for it to become so obnoxious that I had to fix it. One of my cars would suck air into the injection pump and at first, every few weeks I would have to bleed out the air. Finally it got to twice a day and I replaced the fuel filter housing, (diaphragm on top had a hole in it).

This weeks head scratcher was the brake lights stayed on and it was a plastic bumper that disintegrated and I noticed that there is one there for the cruise control switch also. So if your cruise won't work, check to see if the switch next to the brake switch is making contact. (among other things like the little vacuum hoses.)

[Midnightz]

Thanks Al and diesel-man.

Took your advises and checked the fuel lines and the gauge sender. Everything visually was good. Went to Harbor Freight and bought a vacuum/pressure gauge this weekend. It turned out was the restriction was in the priming-pump/fuel filter assy. Replaced the pump and the filter from the sedan and now it runs great!!!!! The filter that was in the wagon was recently purchased Fram PS3720 and it was longer than the filter from the sedan. I was wondering if I bought the wrong filter, (the filter was part number 16405-W2500) or a bad priming pump...

Do I have the correct fuel filter? I want to order another filter to put it back in the sedan.

I've done some research and have a theory. There is a rare condition where non rusty 83 Maxima diesel wagons simply won't run west of the Mississippi river. The cure, obviously, is to relocate them east of the Mississippi - preferably to Tennessee.

I will be selling the sedan soon...

[Carimbo]

The filter that was in the wagon was recently purchased Fram PS3720 and it was longer than the filter from the sedan.

Can you give dimensions? I have seen tall and short versions of the (factory light blue) fuel filters.

[83_maxima]

I wouldn't buy fram ANYTHING. Napa for the fuel and oil filters for me. The exact part nos. are listed somewhere on the site.