Stuck on a Caribbean island (not paradise island)

[Curacao Steve]

Hi all, I have read through the threads (no, not EVERY single one) and can't find exactly my problem. This is a cross post from the new members forum since there are more readers here and this forum is specific to my vehicle

Was driving along fine and the engine died. Multiple attempts at restart with the engine trying (catching for 2 or 3 secs) but then dying. Checked fuel filter (good), fuel pump relay (good), and fuel pump (runs and produces reasonable pressure, but unmeasured). Code 543 seems to be the clue but I haven't found a good diagnostic set of "rule outs" for what the problem might be. Some say cam position sensor (CMP) but there seems to be a large question if my 93 explorer has one. With multiple tries at restarting, it catches or wants to catch just when you turn the key, but it dies every time. Vigorous pumping of the accelerator pedal sometimes produces slightly better results, but again only for a very few seconds. I bypassed the fuel pump relay with a bridge wire (pump running constantly, could hear it) but there was no difference in the symptoms.

Now the fun part: I am stuck on a small Caribbean island where they have lots of cars that are actually composed of several cars, mine included, and they don't always get made into a good car. Mine has been running more or less ok for 2 years, but now it won't start. Parts are horribly expensive here and qualified help is a joke or worth more than gold, and who has gold to pay for car repairs?

I am good with mechanical stuff, but my last car repair days were in the '70s as a VW doctor, and cars these days are certainly not your (grand)father's Oldsmobile.

Helllp!!!

 

[Roadrunner777]

Well... Thank you for a very interesting post! And, lately, the postings have been just terrible in spelling and grammar, so a well thought out posting is more than welcome, well done sir.

Here's where I would go:

As your experience will tell you, engines need fundamentally three things: Fuel mixture, spark, and compression. Compression doesn't go bad suddenly, so I would rule that out.

Fuel is more of an issue than it was in VW days. Back then, you just had to get gas to the carburetor and you were good to go. Fuel injection, you may know is a bit more precise. And, I dare say, most of the postings in this forum have air/fuel as the root cause. I'd suggest, as a first step to get actual fuel pressure numbers. Also, check fuel delivery in terms of volume. Now, I understand your resources are limited. I have been trying to figure out a way to accurately measure fuel pressure without paying some crazy money for a gauge. If you could somehow adapt a regular old pressure gauge to the fuel rail, maybe you do this on the cheap.

I suppose I might even check for good spark before starting on the fuel system. I'm not really big on the CMP as a cause. I see people replacing them as a guess and truth is, it's just an inductor, it's not a moving part. But, it's an easy test, just check for continuity.

Exactly how much of your Explorer is actually Explorer?

Say hello to Gilligan for me!

 

[arco777]

I would lean towards a failed or failing fuel pump. Fortunately the in-tank pump is a very standard style of unit so you should be able to find a replacement, if the output is sufficient.

 

[Curacao Steve]

Roadrunner777, thanks for the high praise (blush). But you caught me. I edit translations for a living, so I am really embarrassed if one of my posts has errors in it.

Thanks for the good basic advice. I will respond more tomorrow as I am just on my way to bed. And there will be questions too!

arco777
Pump runs and has some pressure, just not sure how much. Thanks for the suggestion.

By the way, Gilligan wants to know if you have seen Mary Ann. It's been a while and he's lonely.

 

[Turdle]

Some 93's do have a wired in cam sensor. If you have 2 02 sensors, one on each bank it is likely there is a wired cam sensor.

Now, how do you tell? It is way back on the rear of the engine, tucked in under the upper plennum.

Look for an electric harness going there-follow it to the sensor. Wish I had a picture for you.

 

[Turdle]

Some 93's do have a wired in cam sensor. If you have 2 02 sensors, one on each bank it is likely there is a wired cam sensor.

Now, how do you tell? It is way back on the rear of the engine, tucked in under the upper plennum.

Look for an electric harness going there-follow it to the sensor. Wish I had a picture for you.

Another way to tell real quick. Look at your fuel injectors. Peel back some conduit so you can see wire colors. If all the injectors share common colored wire pairs, no cam sensor. ( all wires red and white). This is batch fire injection


If the injectors all have unique color coded wire pairs, there is a wired in cam sensor. This is sequential port injection.

 

[Curacao Steve]

Turdle: Thanks for the tips. I'll start looking at things this morning.

Roadrunner777: As it happens, I have some spare pressure gauges. I just need to jury rig something to get a pressure reading. Volume is a little more difficult to check. With the fuel pump running, and the line disconnected at the fuel filter, the volume (and pressure) seemed reasonable.
Some have suggested that the IAC or MAF might be to blame. Of course, these functions were served by just a choke and a fuel reservoir in the carburetor back in the day. Not sure how to check either but I guess if I remove all the air ducting I might learn something by trying to start it naked.

I forgot to mention, though not sure it matters, that the engine runs like hell on starter fluid. But then I imagine anything with an intact crankshaft would, even without a spark!

I got my SCUBA certificate in 1960. Didn't do anything with it for decades and then was puzzled as hell by all the gear you need to do basic diving today. There must be a name for this condition. I feel sort of like a time traveler and, no, I was not in prison for thirty or forty years.

I'm pretty sure my X is all X, just probably has 5 or 6 VINs. And when they wired it up, Oh Lord! Actually kind of surprised it ever ran, not to mention actually throwing usable codes for diagnosis. I bought this as the second beater car (first one died after some years) to support my full-time boat building project. Supposed to have my new sailing cat done by 2009. Let's see, lemme check the calendar. Holy sh*t, I missed by a little bit. Sigh, maybe by the end of this year.

Well, at least it's Saturday and I might get some concentrated time to make things work. All comments and suggestions are welcome, though I would plead for specifics. And spelled out part names. The alphabet soup usually takes me some time to find the full part name on the Internet.

 

[Curacao Steve]

Progress??

Well, I finally jury rigged a pressure gauge to the fuel line. The precision of the gauge is questionable (it did read 90 psi from my air hose, so I suppose it's not too bad) but the fuel pressure reading was way under 20 psi. Meanwhile, the pump has started sounding wonky where before it sounded much better.

So, the next step is to determine if it's a voltage supply problem or the pump itself. I resigned myself to cutting open the floor to access the tank/pump (great description at: http://www.explorerforum.com/forums/showthread.php?t=182160 ), tilted the seat forward and pulled back the carpet. No surprise, the floor had already been cut by whoever (re)assembled my X out of who knows how many other Xes.

Now the problem is getting a voltage reading. The wires terminate in molded plastic thingies that are well and truly stuck to the strip on top of the fuel pump assembly. Can't seem to find any bare metal for testing. I don't have a wire piercing probe (eventually I can rig one) and am looking for ideas how to get a voltage reading near the tank without destroying the molded plastic, of course.

Any ideas?

 

[Curacao Steve]

Not paradise island

Oh, by the way, my boat project has eaten all of my money (was it ever not so?) and it's still not ready for the water. So, anybody who saw my mention of it and thought "well that's just some rich bugger who's being cheap", please think again. As I said, this is not paradise island.

 

[rickybobby]

Back in the day, I soldered sewing needles to an alligator clip to have a wire piercing lead that would clip to my DVOM leads. Good luck finding the answer and the parts to make a proper repair.

 

[Curacao Steve]

Update: I managed to use a safety pin to penetrate the wire at the sending unit. But, I only got a reading of 10.24V, with the battery charger on the battery and the voltage at the relay bridge reading 13V, with the pump running. Is a 2.75V drop over that distance considered normal? Anyone know what the pump current draw should be?

 

[Roadrunner777]

The plastic strip is not a connector, it is permanently attached to metal plate. The connection is actually in the left rear wheel well. It is circular black plastic.

 

[Curacao Steve]

Roadrunner777
Thanks a lot. I'll run right out and check it. Of course it did rain this morning and I don't even have a shade tree to work under, never mind a roofed area, so this should be fun(?)

 

[Roadrunner777]

I'm a little concerned about the voltage being so low. The pump should draw 3-4 amps.

 

[Curacao Steve]

Got me before I got out the door. The other day, I used a clip on ammeter over the shorting bridge at the relay box and was reading approximately 1.4 ~ 1.5 amps. So now the question is: is the voltage drop due to the pump or a bad wire/connection? I suppose if I can get at the connector and disconnect the pump, I can check them separately. More to follow...

 

[Curacao Steve]

Well, now we know, but we're still not sure about the unknown unknowns

Roadrunner777

Thanks a lot. You saved me a lot of time.Thanks to the others also.

The fuel pump is bad. The connector had a small amount of corrosion and a little WD40 fixed that. Voltage came right up. Then, when I tried starting the car again, it would run for 2.5 secs instead of 2.0 secs. Big whoop, but at least I know now. I suspect the use of the term 'secondary circuit' in code 543 is a misprint. They should have just said your damn fuel pump is bad!

The final question is, should I spend $135 for a replacement pump only, no sender, (w/sender would cost $180) and which is available online for $35~$80, or about $30 for a local after-market (undoubtedly cheaply made) in-line pump? Clearly at this point, the after-market pump would be more trouble to install, but the $105 difference is tempting. I only need the car to run for another 6 months to a year. Thoughts anybody?

 

[Roadrunner777]

I don't know of an in-line pump that will develop the 35 PSI and flow that you need... but maybe you found something I didn't see.

Otherwise, I would get the pump without the sender, and also the filter sock, so you don't have to go through this again. The fuel lines take a special tool, but I think you mentioned you had one of the lines off the fuel filter, so you would already have the tool.

 

[Curacao Steve]

Roadrunner777
Actually, I fabricated a tool from a piece of small diameter plastic pipe with a slit cut in it. It only worked marginally, might have even damaged the connector as I can now slide the connectors on and off at will (no tool). But, at least at the low pressure put out by my bad fuel pump, they don't leak. Do you have any recommendations for how else make a tool?

 

[Roadrunner777]

I have to say first, you should fix the connector. You probably damaged the little clip inside. It's a Dorman part #800-007, should be available from the same supplier as the pump. I understand budget, it looks like the price of parts just about doubles to get to you. This is 3 clips for $5.00 here in the states.

If I had to make a tool, I would say you are on the right track with the plastic tube idea. There are other kinds, but they would be difficult to make. Examples:

http://www.oreillyauto.com/site/c/search.oap?keyword=ac+&+fuel+line+disconnect

 

[arco777]

The fingers inside the fuel connections are replaceable. Parts stores sell them pretty cheap. They are just round metal tang things.