# Truck won't start



## Nimrod (Jun 8, 2010)

"96 Bronco, 302, throttle body fuel injection, and a distributor. 

It turns over but won't fire. It had this same problem last fall and early winter but it would start if you left it for a half hour or so. It did it about 10 times. I had replaced the distributor cap and rotor last fall. The new cap didn't fit as tightly as it should so I replaced it and the rotor in december. It did the no start a couple more times and has been good until now. I figured the loose cap let in moisture. Also it seemed to do the no start after I had driven it for a short trip that didn't let the engine get good and warmed up.

I will check the spark, distributer, cap, rotor, coil, coil wire, and the ignition switch. I know there is a switch that won't let the engine start unless the clutch pedal is pushed all the way in but if I remember right the engine wouldn't turn over if that was the problem.

Any thing else I should consider??? The fuel pump does run and make noise. 

We have about 8 inches of snow predicted for tonight into tommorrow. LOL


----------



## backwoodsman7 (Mar 22, 2007)

On electronic engines, the first thing to do is pull the codes and see if there's anything there that can give you any hints. Could be a sensor or module somewhere that you'll never find otherwise.


----------



## Roadking (Oct 8, 2009)

wd-40 in the distributor cap.
can you smell gas?

Matt


----------



## arnie (Apr 26, 2012)

don't forget the fuel filter . you may have to buy custom tool replace it


----------



## Nimrod (Jun 8, 2010)

I got a ride to the bar where the truck stranded me last night. It fired right up. I'm back to an intermittent problem. 

Thanks for the ideas from all of you. I will have the codes checked. No gas smell. Fuel filter added to the possibilities but it's a PIA to replace.


----------



## Sawmill Jim (Dec 5, 2008)

Fuel pump :cowboy:


----------



## MichaelZ (May 21, 2013)

Sounds a lot like a fuel pump problem caused by a bad relay. I had a Honda once that had this problem. Won't start, but a few minutes later it will - engine turns and turns. Electronic failures tend to be random like this. As I remember, when we ran the codes it indicated that this was the problem. If this is your problem, it is a cheap easy fix- just plug in another relay. 

If you were getting fuel, you would be flooding your engine. But you say you hear the pump run. So maybe the filter is the culprit. Did you check one of the plugs to see if it was all full of gas?


----------



## Sawmill Jim (Dec 5, 2008)

Being a Ford I still say fuel pump . On some of them the computer times the run time of the pump if it don't pressure up it won,t start . I have turned the key off and on a few times in a row and make it finally pressure up . You probably won't get a code out of it . And it will wait till you have a full tank of gas before it quits entirely :grumble: Running low on gas is a bad thing for in tank pumps as the gas is what cools the pump. :cowboy:


----------



## Nimrod (Jun 8, 2010)

The fuel pump spins right up when I turn on the ignition. It went out once before but I don't remember any intermittent problem first, it just quit. It might be a good idea to have the fuel pressure checked. I should replace the fuel filter anyway so I will try that.

In MN, in winter, I don't let the gas get below a half tank. A habit from the old days when water would condense in the empty space in the tank and cause gas line freeze. The ethanol they put in the gas now absorbs the water and burns so no more gas line freeze.


----------



## Sawmill Jim (Dec 5, 2008)

Nimrod said:


> The fuel pump spins right up when I turn on the ignition. It went out once before but I don't remember any intermittent problem first, it just quit. It might be a good idea to have the fuel pressure checked. I should replace the fuel filter anyway so I will try that.
> 
> In MN, in winter, I don't let the gas get below a half tank. A habit from the old days when water would condense in the empty space in the tank and cause gas line freeze. The ethanol they put in the gas now absorbs the water and burns so no more gas line freeze.


With that Ford just because you hear the pump run don't mean it is pressured up . Also as long as it starts it will show proper pressure if you check it ,been there done it . :cowboy: Try the key cycle thing next time it fails if it then starts it is a matter of time till it quits totally sometimes it will work a long while doing this . Most people will get the last start out of it and have a full tank when it quits or I did :cowboy:


----------



## topofmountain (Nov 1, 2013)

I agree with Jim. I'm a Ford truck former factory trained tech. 

First off if you can hear the pump in the cab when turning on the key you have noisy pumps which is the first sign of failure. 

Second the time to check pressure is when it won't start. Not when it is running OK. I chased mine for a week that way & every time it wouldn't start my gauges were not with me.

Third, use either Delphi or Motorcraft pumps, unless you like changing fuel pumps. Always use a brand new fuel filter after changing the pump. 

Fourth a bad pump won't throw a CEL most of the time other than a lean 02 sensor sometimes.


----------



## Nimrod (Jun 8, 2010)

The saga continues. 

I may have this figured out. The truck started OK all summer long so I thought I had it fixed but it started doing the same no start problem as soon as the cold weather hit. 

I researched the problem with the new info and it sounds like the "intake air temperature sensor". This is in the plenum for the air filter and tells the computer the temperature of the incoming air. It does this by changing resistance as the air temp changes. The computer uses the air temp to figure out the density of the air. Then it knows how long to open the fuel injector during start up. The colder it is out, the more gas it has to let into the cylinder to start (In my day this was what the choke was for).

I pulled the sensor and it showed infinite resistance on the Ohm meter so it is bad. The parts store is ordering a new one ($17) and I'll give it a try. 

Looks like Backwoodsman was right. I wish he had been a bit more persistent. I thought there would only be codes if the "chuck engine" light came on. Engines have gotten a lot more complicated since my day. When I open my diagnostic tool kit there is a compression tester, a vacuum tester, a timing light, and a remote starter switch that are still useful. The dwell/tach meter doesn't have much use and the fuel pump tester only goes up to 10 PSI. LOL

I'll post after it's been in use for a while and I see if it fixes the problem.


----------



## backwoodsman7 (Mar 22, 2007)

Nimrod said:


> I thought there would only be codes if the "chuck engine" light came on.


I'm pretty sure I've never seen a "chuck engine" light, but I've certainly had situations where it would've been a big help.


----------



## kycrawler (Sep 18, 2011)

I at sensor generally won't cause a no start. On that particular truck I would be looking hard at the fuel pump or the ign module


----------



## Chief Cook (Apr 24, 2011)

Sounds like a ignition module, Fords can go out and restart. Chevys go out they are dead, just dead. This is from DH, he is in charge of the shop for our city. He and his crew works on everything with or with out a motor! Hope this helps.


----------



## Nimrod (Jun 8, 2010)

It only does the no start in the cold weather and only once in a while. If you let it sit for 20 minutes after a no start, it starts right up. I'll try the sensor and see if it fixes it.


----------



## bikehealer1 (Oct 8, 2009)

kycrawler said:


> I at sensor generally won't cause a no start. On that particular truck I would be looking hard at the fuel pump or the ign module


My dad had a 96 Crown Vic that had these exact same symptoms years ago. My uncle, a master mechanic, and his guys puzzled over it for several days til one decided to replace the IAT sensor. It can be bad yet will not throw a code. Car ran perfect thereafter.


----------



## Danaus29 (Sep 12, 2005)

I was going to suggest checking some of the temp sensors. I had issues with my car not starting when warm (in the summer, ran great in winter) and it turned out to be the air charged temp sensor. Sensors are a cheap easy fix and the best place to start.


----------



## Nimrod (Jun 8, 2010)

Don't want to jinx myself (knock on wood) but it hasn't had a problem for almost 2 weeks now. It begins to look like the intake air temp sensor was the answer. 

The only downside is that there were 2 possible replacement sensors. One screwed in and the other just twisted a quarter turn and locked. Mine was the quarter turn one and it was $30 not the $17 I originally thought.


----------

