Intermittant no start

[Greg C]

My truck is a 95 4WD 4.0 SOHC with factory power electronics (seat, windows, doorlocks), theft, and towing packages.

Over the past several weeks, my '95 fails to start intermittently. The starter will spin the engine but the engine fails to catch. After a period of time, about 30 minutes, the car will then start. The problem only occurs on start up, it never dies when running.
I've had this to a mechanic, but the problem never surfaced for them. In addition, the engine light never came on therefore no engine error codes to use as clues.


I thought it might be related to the Locktronics security system but the Dealer reported that the started's power would be cut which rules it out.


Intermittent electrical problems have also arisen in other areas which may be clues: 1) intermittent wiper speed fluxuates, 2) auto door locks are not consistent in operation (sometimes they unlock).

If I remember my basic auto repair, you need fuel, spark, air, and compression for the engine to operate. The intermittent no-start would eliminate all but the fuel and spark I believe. I could rig up a fuel pressure gage and spark indicator to narrow down the possible causes.

Any advice would be appreciated!

 

[Ira]

I would check fuel pressure. It is common for the check valve on the fuel pump to go bad and allow the fuel to leak back into the tank when it sits for a while. It will take a little while for it to purge the air from the fuel line and get fuel back to the injectors.

If all else fails, then check for spark. You just need to be able to do both of these checks when it will not start.

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Ira
91 XLT 4x4

You're just jealous because the voices only talk to me.

 

[BeginnerXplorer]

I recently had the same problem with my '94 Explorer XLT. Are you ready for a list of all the work it took me to fix it. After many trips to a mechanic (and many hook ups to a computer to tell me nothing was wrong), this is what was figured out. Here goes:
1) Go to Ford dealer
2) Ask for a Fuel Pump Relay, cost $9.40 including tax
3) Pull out old one
4) Insert new one
5) Done!!
I was a little hesitant to believe that this would slove my problem, but it did. I also had the same problem with my A/C and replacing the relay worked there too. Let me know if it works.



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"If it was easy....everyone would do it!!"

 

[Greg C]

Ira,

Could a check valve failure be intermittent? If so, and the fuel lines were drained of fuel, how long should it take the lines to be filled?

Where is the check valve located? What is involved in replacing the check valve?

Greg

 

[Greg C]

BeginnerXplorer,

Sounds encouraging! Might be the best $9 I've spent.

What were the clues that led you to replacing the relay?

Greg

 

[ExploreMinnesota]

The relay solution sounds very probable. One way to know if that's the problem is to listen for the fuel pump when you turn the key on before attempting to start it. You should hear the fuel pump for a brief second. If you do not hear the fuel pump when you turn the key on when the problem is occurring, then replace the relay. If you hear the pump and the engine will not start, then the relay is working fine.

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ExploreMinnesota
91 EB 4x4 Stock

[This message has been edited by ExploreMinnesota (edited 05-24-2000).]