I would replace the relay for the fuel pump since it kinda showed on the codes you said. My 4.0 (94) was bad about not starting sometimes. changed te fuel pump relay, kept the old a s spare to see what happens. I found the relays can get heat soaked in hot weather snd just dont respond right. I can take it out blow on it, get it to cool a little and it will start right up. thus I keep a spare inone of the empty slots. next time wont start, look under the hood to the relays you ID'd, find the furl pump relay pull it out feel if hot, try to cool reinstall. If starts right up I would think you found your problem. What causes it ther than heat not sure. I have not read alot on any board about the cam sensor or sensor in general so I defer to the gentlemen that raised them as possibilities. what ever y ou find out please repost as mst folks dont tell what they found so few folks can build up a knowledge base.

 

I provided a link with the replacement part number. If you have a Kragens/Checker Auto parts/Schucks (or whatever it is called), you can pay for it online and pick them up at a local store. $2.79 each.

 

I had an 78 Cadillac that wouldn't turn over but sometimes it did. The starter always checked out when I took it out and had it checked at Auto Zone. I finally took the starter apart and all it needed was three dollars worth of new brushes. The old ones were worn down. So if the problem is sometimes your starter turns over but then sometimes it don't; you might check this problem.

 

Well using your relay diagram of the three larger relays, according to my manual #2 would be for the computer & #4 would be for the fuel pump.

So, seeing as how one of your trouble codes is for the fuel pump having low voltage, maybe begin with relay #4, next time it cranks, but wont start & run.

Thump it, or replace or swap it, with a like relay.
Or seeing as how you said the vehicle was involved in water at one time, pull the danged relays & inspect their contacts & the distribution box sockets for corrosion.

 

Again<O:p</O:p

Thanks to this forum for helping<O:p</O:p

Fomhoire, indeed, the link you provided has a relay – ignition (multi use)<O:p</O:p
http://www.partsamerica.com/ProductDetail.aspx?MfrCode=NIE&MfrPartNumber=RL366 21&PartType=588&PTSet=A <O:p</O:p
<O:p
I ordered to have it picked up at the Advanced Auto store down the road, but the checkout online says<O:p</O:p

…The products in your cart are only available for shipment directly to you…<O:p</O:p

The cost would 9.31.
Shipping is the killer at $6.52
I called the Advanced Auto store today. They have a relay for 11.88 plus tax..
<O:p</O:p
I pulled out the Owners Manual that my father had. Looks like it was soaked in water!<O:p</O:p
I guess they lost the original because this one is for a 1994 Ranger.<O:p</O:p
<O:p
In it, the Power Distribution Box diagram has six the same size boxes at the top all labeled relays<O:p</O:p

They are <O:p</O:p
<O:p
O 2
3 4
O 6<O:p</O:p
<O:p</O:p

2 is A/C W.O Relay<O:p</O:p
3 is Fog Lamps<O:p</O:p
4 is Fuel Pump relay<O:p</O:p
6 is E.E.C Power Relay
O is open relay<O:p</O:p


The 94 owners guide diagram does not appear to be the same - it does not show the smaller relays at the top. Based on my earlier post of what I actually see, it does not match.<O:p</O:p
<O:p</O:p
Pawpaw, do you have the 95 Ranger manual?<O:p</O:p

Does it show the small relays as in my diagram I posted earlier as compared to 94 diagram showing all the same size?<O:p</O:p

 

The 94 & 95 power distribution boxes were different.

The first one you outlined, matches the pictorial I have in my repair manual for a 95 & yes it shows the 4 smaller relays in the 95's power distribution box.

Call around to different parts houses, I've seen these relays for as little as $6.

 

I will check around for a better price...

Here is something interesting to note what I found today…

I went out and pulled the relay #4 - fuel pump to check the ends.
They looked ok. I reinserted the relay and decide dot try to start the truck...

Darn if didn’t want to turn over!
I went out and tapped on the relay and tried again and it would not turn.
I tapped on the top of the relay and pushed on it.
Tried again would not turn. I went out and tapped a littler harder and it finally turned over..

Now is it a coincidence that it turned over on the third try as it did in the last month or is it really the fuel pump relay?

Is there a way to test the relays at a local shop or with some type of meter?

 

Won't cost anything, so why don't you try swapping the #1 relay in your diagram (the WOT, Wide Open Throttle relay), with the #4 fuel pump relay & see what happens.

I don't think your gonna be doing any WOT stuff any time soon, so if the fuel pump relay has a problem & is in the WOT position, the computer won't care until you get crazy & go WOT!!!!!!!! lol

If that doesn't have any affect, then swap the #2 ECM relay with the #1 WOT relay & see what happens, or just go buy another relay & swap it out between the #2 & #4 positions & see what happens.

Just a couple more test thoughts.

 

Good idea on the swapping..
I will try it out..

Yeah. WOT.. on my truck would be miracle a

 

I swapped out the WOT with the Fuel Pump relay.
Started up the truck. (did it 3 times)

Let it sit for a while and started it up..

I will get a new relay and put it in the WOT position (to be safe)

I will see what happens while driving locally...and check back

 

We have been having this intermitent no start problem with my wifes 94 B 3000 for some time. When it happens we flick the relays, change out the relays etc. I bought a new one at NAPA for about $20 and one at Ford for about the same, we change them move them flick them.....eventually it will start and be OK for a while. Today it happened and nothing worked. She left it sit for a while and went back and it started and was OK again. I am wondering if there is a circuit breaker that powers these relays that kicks out and then comes back on after a while. Maybe it is not the flicking, changing, moving that is making it start but time and waiting. How can we get to the bottom of this problem?

 

TomA92, have you had the computer scanned for trouble codes???? There can be pending codes in there, without the CEL being on, that might offer up a good clue, on where best to begin your toubleshoot.

You may have more than one problem too.

If the starter motor cranks the engine at normal speeds ok, but it just won't fire & run, you need to check for spark & fuel delivery pressure, when it's acting out.

If you have a inductive type timing light, just hook it to a spark plug wire, when cranking the engine, to safely check for spark.

You can borrow a fuel pressure gauge from most auto parts stores "Loan-A-Tool" program, to check the KOEO & KOER fuel pressure.

If it's slow on crank speeds, you need to load check the battery & check the condition of the battery cables & their connections on BOTH ends, as battery voltage drop, when cranking the engine, will also affect spark & fuel delivery.

If you don't hear the fuel pump run for about two seconds, when you go to KOEO, suspect your fuel pump relay, or it's circuit, or the fuel pump, or the ignition swtch.

If you don't have any instrument panel warning lights on, when it's in one of it's no start fits, suspect the Computers power relay, or the ignition switch.

Just some thoughts to ponder & things to try & isolate your intermittent no start.

 

The only trouble codes that come up indicate bad oxy sensors. The check engine light will come on after too much low rpm running. It will go out after returning to over 2000 rpm for about 5 or 10 minutes. This does not appear to be related to the no start problem.

I do suspect the fuel pump, the truck has 192,000 miles on it. A while back I searched this board for this problem and the concensus seemed to be that if the fuel pump was bad it would quit while running. Once started it will run and run. When it won't start I cant' hear the fuel pump whir. Once I turn the key and hear it click and whir it will start. I have hessitated to change the pump because of having to drop the tank, also I am keeping it full to keep the pump cool so there would be a lot of gas to drain. I have not checked the price of a new pump yet either. It only seems to happen about once a month. Now the AC is leaking so it may be time to replace the truck.

 

Well if your intermittently hearing the fuel pump before start, then you likely have a electrical delivery problem to the pump, of some sort.

Could be the ignition switch, fuel pump power relay, the fuel pump itself, or maybe the computer's power relay is acting up & timing the fuel pump run cycle short.

I'd try thumping both those relays, in turn, when you don't hear the pump run for about 2 seconds, when you turn the ignition switch to KOER, but before you go to start & see if you can wake it up. Or maybe try swaping those two relays in turn, with a like one, not needed to run the engine & see if things improve.

Might be helpful to know the O2 sensor codes you have.

If they are lean codes, it could be caused by a weak ot intermittently operating fuel pump, thats causing intemittent delivery & is causing a artificially lean A/F mxture.
So a fuel pressure, or delivery rate vs time check might be in order.

With the mileage you have on this ride & if the O2 sensors are origional, they are likely
just tired, lazy & slow to react.

If you come to determine the fuel pump is just worn out & must be replaced, consider removing the bed, to access it.

Most folks think this method of accessing the pump is easier. Loosen the bed hold down bolts, disconnect the tank fill tube & disconnect the brake light harness & slide the bed back, to access the pump, without having to drain & drop the tank.

Just some things to ponder.

 

pawpaw said:

"I'd try thumping both those relays, in turn, when you don't hear the pump run for about 2 seconds, when you turn the ignition switch to KOER, but before you go to start & see if you can wake it up. Or maybe try swaping those two relays in turn, with a like one, not needed to run the engine & see if things improve. "

Thanks for your insight pawpaw, we have done all those things. This has been going on for about a year. It only happens about once a month but it happened last week and my wife flicked the relays and swapped them and nothing. Then she went and had a cup of coffee and came back and it started. She needed to make a trip to Carson City yesterday (about 250 miles) so she borrowed a friends car. Her friend drove the Mazda to the park and ride and took the bus to work. When she came back it started right up. She drove a couple of miles and stopped at the store, when she came back out it wouldn't start again so she walked about 2 blocks home. Later my wife got back from Carson and it started right up. Time seems to have a lot more to do with it than anything.

I know the fuel pump may eventually fail. I am thinking *maybe* it is getting old and a little stiff to start or something, but as I understand it, it cycles on and off continuously while the engine is running. It never stops when it is running. only after it has been shut off. With what you describe of taking the bed off to change the pump, I hate to change it just to *see* if it solves the problem. I would like to figure out what the trouble is for sure before I ust go ahead and do that. I wonder if it would help to try to pull codes when it its in the no start condition. That is hard to do because it seldom happens at home. I am now suspecting a computer problem or maybe some sensor.

Thanks for all your help.

Tom