Hard Starts

[pearsonbe]

Have a new problem with the Explorer. Recently, the fuel pump and starter were replaced. The truck ran fine. The positive cable was in bad shape so it was replaced. Immediately, it was hard to start. I noticed the positive cable was loose at the firewall. Tightened that and it started right up. The next day the problem was back. Takes 5 or 6 loooooong cranks to start the engine.

Today I checked the battery, connections, grounds, alternator, and fuses. Everything looked fine. Fuel pressure reads 40psi before startup and 30psi while running. It will start right away when I spray carb cleaner in the intake and continues to run until I shut it off. This leads me to believe it might be an injector issue.

 

[pearsonbe]

I found two threads on the forum that say the fuel system could need a major cleaning, the IAC is bad, or there is a problem with the temp sensor. I will investigate.

 

[Wolfie_85]

Check your fuel pump relay for good measure. To test it, swap the A/C relay and the fuel pump relay. Mine did the same thing. When it ran, it ran, but getting it started sometimes was a pain. If it stops giving you issues, that's it. Have you replaced the fuel filter? Does it do it intermittently? Warm or cold?

 

[pearsonbe]

Thanks Wolfie.

Just checked the IAC and temp sensor. Still not sure about the IAC. It passed the continuity test but I couldn't tell if it was getting power. Voltage kept moving around (KOEO). The temperature guage works so I didnt mess with the temp sensor. Today I tried carb cleaner in the intake and it still didnt start. So maybe it was a coincidence yesterday.

The fuel filter was replaced with the pump. It is hard to start mostly when it's cold. My son said it starts faster when it's warm. Today I let it get up to tempearature, but it still wouldn't start after I shut it off.

Will try swapping relays.

 

[2stroke]

One thing that stuck out to me was when you said you tightened the positive cable to the fire wall. Neither my 94 explorer or 94 b4000 positive cables are attached to the fire wall that I can see from under the hood. I wonder if it is keeping the starter from getting the current it needs to turn. If it turns slowly, especially when cold, it is entirely a starter/electrical problem.

 

[pearsonbe]

"One thing that stuck out to me was when you said you tightened the positive cable to the fire wall."

2stroke, from the positive battery terminal, there is a red cable (4 or 6 guage?) that runs to one side of the remote solenoid. On the other side of the solenoid, there is another small red cable (about 10 guage) that goes into the harness somewhere. I was referring to the solenoid connections that were tightened.

I pulled the green (EEC?) and brown (Fuel Pump) relays and checked the connections. Without the fuel pump relay, the pump wouldn't work. Works fine with the relay, so I think both are good. I tried spraying carb cleaner in the throttle body again and it started right up. This time I used the red straw to get it further in the body. Repated that and it started. Temps outside are higher so maybe that had something to do with it too.

I'm going to replace the plugs and try a good injector cleaner. If that doesnt work maybe I should manually clean the injectors or replace them.

 

[2stroke]

Oh, you are referring to the mega fuse. So it cranks over at a normal speed, it just doesn't fire?

 

[pearsonbe]

"mega fuse"

Lol. It's a fuse?

Yes. It cranks at normal speed, but doesn't start.

 

[2stroke]

Yes, it is a 175 amp fuse. Have you reset the fuel pump shutoff switch?

 

[acschilling]

Am experiencing a similar issue..Cold starts take a longer and when it's hor it it'll fire like the timing is super advanced or something...literally maybe one turn before it's running. Rando hot misfires and such. Vague scent of raw fuel when really hot. If I could just throw money at it I would go for injectors.

 

[2stroke]

Am experiencing a similar issue..Cold starts take a longer and when it's hor it it'll fire like the timing is super advanced or something...literally maybe one turn before it's running. Rando hot misfires and such. Vague scent of raw fuel when really hot. If I could just throw money at it I would go for injectors.

Your problem sounds more like a bad MAF to me.

 

[acschilling]

Your problem sounds more like a bad MAF to me.

I swiss cheesed my air box probably two years ago has that been doing terrible things to air/fuel ratios?

 

[2stroke]

No, you can do anything you want before the MAF.

 

[pearsonbe]

"Yes, it is a 175 amp fuse. Have you reset the fuel pump shutoff switch? "

No. Could that cause hard starts? I would think it wouldn't start at all. Where is it?

At this point, I feel like the replacement cable is the problem. It is a cheap universal part that was rerouted from the battery to the starter. The smaller wire that goes to the solenoid from the original cable was reused; however, the large factory cable was disconnected from the battery and starter. Now that I know the factory cable is not basic, that's likely the issue since the truck started ok before the cable was replaced. I took a couple of tries when cold but it always started.

 

[acschilling]

I saw what looked like a large ground wire through the passenger side fender-well, behind the coil spring that looked connected to the frame..it looked pretty dirty but kinda tough to get off. I assume it's a battery cable only because it's directly under the battery (just seems to run a couple feet down). You could also have a peek and see what you think. I had my + cable switched a few years ago because of corrosion inside the wire and now I can see it happening again. If yours is bad, no doubt changing it would improve starts a bit I'm sure. Is your charging system under powered? Mine might be..the only thing I have added to the battery and stock 95 amp alternator is an amplifier.

 

[2stroke]

If it ran good before, and the starter turns fine, it has to be the positive wire. I would get a good picture of the mega fuse and make sure its hooked up right. Since you have good fuel pressure, it has to be an electrical problem. I would pull a spark plug after turning it over, and hopefully it will be wet. Then I would check it for good, blue spark. I will post a link to battery cable routing. I don't see any mention of the mega fuse, but there is a good picture of a "starter relay" AKA solenoid. That is sometimes located on the fender wall, probably on the passenger side, but not always. The mega fuse is a big block, and can be found on the firewall, its not on every vehicle.

http://www.explorerforum.com/forums/showthread.php?t=250186

 

[pearsonbe]

As far as the charging system, everything is stock. No amps or additional draw on the system. The battery was replaced one or two years ago. When I checked the battery before starting it was 12 or 13 volts. While the engine was running I remember seeing at least 15 or 16 volts. Whatever it was it was ok according to Haynes. If the cable wraps around the engine it sounds like a pain to replace.

Thanks for the info and link. I'm reading now.

 

[BKennedy]

I noticed that my Explorer would have hard starts when the battery was going bad. It cranked fine by sound, but a few weeks later the battery would need to be replaced.

Ford uses a remote solenoid. That is where the main positive wire feeds into from the battery. There should also be a secondary wire attached to the positive terminal that goes to the starter. At the solenoid, there is one large gauge wire that splits into two separate wires and then goes back to one wire again. That is the 175 amp "fuse". The wires melt, saving the electrical system.

The solenoid is relatively inexpensive and can be found at any auto parts store. They occasionally slowly go bad, also creating a hard start issue before they quit altogether. I had that happen several years ago. Buy another and throw it in there. If it doesn't help, keep the old one for a spare.

On another subject: I cut several round holes in my intake box and had it like that for many years. Now, I am running a 99 intake box because I needed the space for the coil over shock hoops/SAS. The 99 box is not hooked up to any of the stock hoses, leaving a large oval hole on the side facing the front of the Explorer, and I had to add all the 94 pre-heater smog crap to the underside, leaving another large space for air to enter the box. Started right up, no issues in over a year.

Noticed you replaced the fuel filter so that is not it. I replaced mine recently when I ran the tank very low and the pickup sucked a bunch of crap into the filter. It would surge for a few seconds after starting.

 

[pearsonbe]

BKennedy you may be right. According to the link provided by 2stroke, I should see (much?) more than 10 volts at the battery while cranking. Yesterday, I read about 10.5 volts. And it does sound fine while cranking. Ok, I thought the solenoid/relay was an all or nothing situation. I will replace it first, then the battery, if necessary.

 

[2stroke]

No need to replace the solenoid. It is a kind of all or nothing deal. The battery should have more than 12.6 volts after sitting all night (after a full charge). Other than that, the only reliable test you can do is a load test, and it might be a good idea to have it done. First I would clean up the top of the battery good, and make the cells are full of water. I think what BKennedy might have happened is the battery did not have the power to supply to all of the truck. I've never had it happen without a slow crank, but I'm not going to say its impossible. I still say it has to be to do with your battery cable, unless it was having some problems before hand. Since you replaced your fuel pump, I wonder if you had hard starts before?