1994 Explorer unpredictable starting

[JRayFL]

I have a 1994 Explorer that occasionally will not start. This problem has a mind of its own and doesn't seem to have any pattern other than the car has been driven for a while, shut off, and then started again. It will run fine then when I shut it off and come back to start it up (20 minutes or so) it just cranks without firing up. The symptoms are just like the thing ran out of gas (checked that the first time, don't worry). This problem has not occurred from a cold, cold start (greater than 12 hours sit time).

I have replaced the fuel pump and fuel pump relay. I am confident fuel is at least getting up to the injectors. I have heard that this "sounds like a computer problem", but I have no idea. Any suggestions on cause, trouble-shooting technique, or repair are appreciated.

 

[Gary Steeber]

JRayFL
Your problem sounds so random, it's hard to pinpoint.
The only thought I have is that maybe you have an ignition switch going bad. Other than that it may be injectors or the ignition module.
Goodluck, maybe someone else has some good methods of checking these things out.

 

[Goober]

check the battery cables, lots of folks here(including me) have had problems with corrosion inside the cables. Hope you find your trouble.

 

[kilroy]

Vapor lock. You may have an injector that is leaking, and after sitting for a while the manfold gets "heat soaked" and the leaking fuel vaporizes in a sense flooding the engine.

Try this, after the engine has been off for a while, take the intake hose off the throttle body, open the throttle and smell for gas fumes, if you smell strong fumes that would be the likely culprit.
Note: you will smell fuel, but very slightly, even if the injectors aren't leaking.
I saw one once where I opened the throttle and a mist of gasoline came out the injector was leaking so bad.

 

[ScottXXL]

Same problem happend to me a couple of weeks ago. Unpredictable starting, plenty of battery power. It was a bad starter silinoid. Replaced it for $14.99, and installed it myself...very easy. It is located on the passenger side near your airbox. At least for my 92.
Get a shop to check your electrical power out put, unless you can do it yourself.

Hope this helps.

 

[leebo]

I'd also say the battery cables. That's what the problem I have at times. All I do is hit the positive cable and all seems to work fine.

 

[kilroy]

If it's cranking, I doubt if it's the cables.

 

[Big E]

Kinda curious if you solved you problem or not. I am haveing the same problem. But my Exploere will crank and not start but if I cycle the key on and off it will finally fire. I am thinking it might be a faulty fuel pressure regulator or a leaking injector. I will keep you posted on my findings and maybe it can help you out. I have already checked all the simple things, like battery, battery cables, starter, good ground to the engine.


Eric

 

[Ray Hutchinson]

No Start

JRayFl,

This sounds identical to the problem two friends had on each of their explorers. In both cases, they sometimes wouldn't start, after being run and well warmed up, shut off , then attempted restart while still somewhat warm.

Both cases it was the EEC relay. This relay is located in the fuse/ relay electrical distribution box under the hood. The fuel pump relay is the identical part. The relays are available aftermarket for about $20 each. Often it is reccomended that both be replaced, because if one fails, the other probably will soon. This is a relatively cheap troubleshooting procedure: Buy a relay and replace the EEC relay. If that's not the problem, its still a good "spare" to have along on offroad trips, since it is good for either the fuel pump or EEC, anmd they do fail after a 5-6 years.

Oh yeah, If the battery cables are bad it likely won't crank: except: it youv'e got the Two: (One large one smaller ) cable system, with both comimg into the + battery terminal. Be sure there is no corrosion, and the smaller cable still has a good connection. Tug on this smaller cable a bit to make sure it hasn't corroded through and is still solidly connected to the battery terminal cable clamp.

[Edited by Ray Hutchinson on 11-14-2000 at 11:17 PM]

 

[Houston at NCSU]

Its definetly the EEC relay, I had the same problems with my 94, and i replaced the fuel pump relay, and the problem was less severe, then i replaced the EEC relay, and the problem went away all together, get a delco relay if possible, 7 bucks at autozone, the 4 buck no name relays at Oreilly's dont last more than a couple months.

 

[JRayFL]

I finally got my problem resolved several months ago. A mechanic suggested that I replace the main relay. He had seen a similar problem on an Explorer like mine. I am not an expert on this but it seemed to clear up the problem. My explorer has had a history of relays going bad (A/C just recently) or sticking so this is not a surprise. Regardless, the problem has not come back (fingers are crossed).

 

[John Schumacher]

I have a similar problem with intermittent not starting. 99.99% of the time it starts on the first try, in fact if it doesn't start on the first try it usually means that it won't start for 30 min. This situation usually (NOT always) occurs when the engine is warm and after sitting for 15-30min., but also sometimes when cold (50F) after sitting overnight. PLENTY of cranking power, but not even a hint of catching. Almost invariably starts on the first try if I leave it alone for 30 min. Runs excellently when starts. Goes for months without a problem, then wham, a week of intermittent starting.
Just last night had to be towed home from the mall. Classic scenario. The hook up and tow took about 30-45min. After the tow truck left, my Explorer started on the first try, so I drove it right into the garage. Started on the first try in the morning too. Good thing I have emergency road service.
A while back I decided to buy an AutoXray OBD II scanner since the problem was so intermittent. Had it for a month before it didn't start again, but when I plugged the scanner in, it said "Vehicle not responding". HA-HA, but a clue nevertheless since once it did start (1/2 hr later) the scanner worked fine, but no trouble codes to give me a lead. Same thing again on Tuesday.
I now suspect the ignition switch, but from reading different postings I may try the EEC or Fuel Pump relays. If it wasn't for this one problem, I'd say I have a great vehicle--never misses, hesitates, stalls or dies, so I think that eliminates the MAS, cables, tune-up, rings, fuel pump(?), injectors, etc. Check my logic.
Anyone found any definitive culprit for this situation? If not, I'm buying the relays and will install them the next time it won't start, and I will report the results for posterity.
Thanks for all your input. I'm looking forward to getting to know you all and familiarizing myself with the site.

 

[oahrens]

Hey John!!!

Welcome to the board.

You're on the right track as far as you're starting problem.

Nice detailed post for your first....Here's to ya

 

[TPLYNCH]

John, welcome to the site. Before turning the key all the way to start, pause at "on" and listen for the fuel pump whine. If you don't hear the whine, and the truck does the no start, then pop the hood and tap on the relay box, or open the box and jiggle the FP relay (with the key in "on" position). If is the relay, or the connection in the box, you should hear the FP whine when the connection is good. If the FP always whines before the no start, then your problem may lie elsewhere. That's when you have to check for spark etc. while its cranking. Possible causes - bad connection to Crank position sensor or bad sensor itself, and maybe bad coil pack.

 

[John Schumacher]

Thanks for the welcome oahrens.

Tom, I'll take your advice the next time it happens. I sure hope it isn't the crank sensor or the ignition box, but if it is, at least I'm still under my used car warranty.
I bought a relay just in case that's the problem. I was going to get two, but they only had one left--common problem so they're going like hotcakes?
While thinking about it today, I realized that I had neglected to mention the hood switch that I read about here. I assume this is something they put in so you can't drive with the hood unlatched.
Another thing that's been happening lately is that when I activate the right turn signal, I am sometimes getting a sound like a warning buzzer! If I put the signal lever to high beam and then turn it on I don't get the buzzer. I hope there aren't loose wires in the steering column that are causing this and the starting problem. What a mess that would be.
Anyway, thanks for the welcomes and the feedback. I hope to report success with a fix in the near future.

 

[ddenton749]

'93 With the Same Problem

My '93 has the exact same intermitant starting problem. Every once in a while it won't start after sitting for several hours. (Overnight or all day at work)It happened just this morning. If I go under the hood to the power distribution box, remove the EEC and Fuel Pump Relays, put them back in, it will start. However, I usually have to play around with the EEC relay (take it out, put it back in) until I hear the fuel pump kick in. This takes several attempts. Both the EEC and Fuel Pump Relays are new - replaced last week. Does the computer send power to the EEC relay, which then sends power to the fuel pump relay? What else would keep the EEC relay from sending power to the fuel pump relay?

 

[dogfriend]

something else to check

A couple of years ago, I had an intermittent no start problem with my 89 Ranger. This would occur after driving a few miles in warm weather, shutting it off and then trying to restart. It would crank fine but no start. After leaving it alone for awhile it would usually start but not always. I had to get towed a couple of times. Scanning did not give any stored codes.

I finally was able to trace the problem when it finally refused to start at all. It was the ignition coil of all things. I had replaced the coil with an aftermarket "performance" coil and it developed high resistance across the windings (probably a connection was loose inside) This is very easy to check with an ohmmeter. If your starting problem only occurs when hot, check the resistance when the coil is hot.

I also had the starter relay on the fender fail once, but it was easy to find because it was making a "rattle" noise as it tried to close the contacts.

 

[dogfriend]

oh yeah

Before someone flames me by pointing out that the Explorer doesn't really have a coil, you're right. BUT the coil pack is actually 3 ignition coils which are fired by the computer, so I would still check the resistance. It doesn't cost anything but a little time.

 

[ddenton749]

I read the EEC codes today and got:
172 something about the O2 Sensor being lean
542 Open Fuel Pump Circuit...
543 Open Fuel Pump Circuit...

Can anyone describe what these mean and where to look for the open FP Circuits? My starting problem seems to be centered around the fuel pump and EEC relays.