93 xlt won't start when warm. | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

93 xlt won't start when warm.

cunnidj

New Member
Joined
January 26, 2007
Messages
7
Reaction score
0
City, State
Lohrville Iowa
Year, Model & Trim Level
93 XLT
About 3 weeks ago it got very cold, -20 my fuel lines froze up. I got it into our shop and thawed out, drained the gas out replaced with fresh and water remover, changed the fuel filter and spark plugs. the truck will now start and run rough, if i step on the gas hard, it wants to die like it is being starved for gas, if i give it gas slow it will rev up. i have been checking other threads and found one that refered to the FPR (fuel pressure regulator). i pulled the vacuum line and gas came out so I replaced it. now the truck will start and run rough llike before, but when it gets warm and i turn it off or it dies, it wont start again until its cooled off. It acts like it is vapor locked. I released the fuel pressure at the fuel rail by the injectors and alot of air comes out not much fuel. I followed the fule line to see if it was near the exhaust, possibly causing fuel evaporation in the line and its not. if I spray some gas into theintake it will fire and run till the gas i sprayed is gone. please help thank you
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.











thank you for the welcome and puting me in the right place. I don't have a fuel pressure gauge yet, but when it wont start there is lots of pressure but most of it is air. more info. 93 explorer 4.0 EFI, the motor is 94 but the body is 93 if that makes a differnce. I have to work for the next 5 days and will get back to it on monday. I will check the engin coolant temp sensor, I found a thread talking about it and a table for voltage and ohms. any other suggestions will be greatly appreciated.
 






just came in from working on truck, cleaned every sensor I could find, and checked the engine coolant temp sensor it seems to be working fine according to a chart i found in one of the threads. Hooked up a fuel pressure gauge, just turning the key it read 2psi, with the truck running it read fluctuating between 5 and 9 psi. so next step is look into a fuel pump, i guess unless anyone has any other ideas.:roll:
 






I'd start with the cheap and easy first. How's the fuel filter? Has it been replaced lately?
If not I'd start there.
 






I have changed the fuel filter, spark plugs, the gas, and the fuel pressure regulator. and still no change
 






If the pressure is only getting up to 9 psi, then it's not going to start. Spec is 40 psi, and my unscientific minimum is 20-25 psi. We might asssume the regulator is good because it's new, but you might want to check it (pull the vacuum line again and check for gas. disconnect the return line from the regulator, ground the pump test lead, and see if fuel is getting past the regulator at low pressure. Pay attention so you don't spray gasoline everywhere).

If the filter is clean, the FPr checks out, and there are no kinks or clogs in the fuel supply line, then I would expect something is wrong with the pump.
 






Welcome to the site!

I agree with mrshorty, but it also couldn't hurt to make sure the fuel pump relay is good, and all electrical connections there are clean and making proper contact. There are volumes written here about this.

Mike
 






thanks, I did pull vaccum line from new regulator no gas came out fuel lines are strait, there is a new fuel filter. I had a friend help me look at it, when it started to die he sealed the intake manifold with his hand and it kept runing until he removed his hand. Once it was warm I tried to start it again I didnt hear the fuel pump start when I turned the key. Also can anyone tell me how to check the fuel pump relay?
thank

Craig
 






Relay is a simple switch that is either open or closed. I would jumper the fuel pump test lead (short end of the self-test connector, KOEO) which should close the fuel pump relay. Then put a voltmeter on the wire that goes to the pump. If you have less than ~10 V, then put the voltmeter on the wire that comes from the battery (yellow I think, a wiring diagram will help to identify wires). If you have battery voltage there, but less than that downstream of the relay, the relay isn't closing.
 






possibly fixed

I dropped the tank today to change the fuel pump, when I pulled the old one out I noticed the red wire connector on the pump was loose. I looked closer the connector was broken, so I cut it off and replaced it with another 19 cent connector, put it back together to try it and it started and ran. now I need to return the other pump and try the truck for a few days but right now it seems to be working just fine, Thanks again for all of the advice.

cunnidj:):salute:
 






one more question
my next project is a 1987 Caddilac Seville, that wont start at all it will fire then I get a code that says open circut in fuel system.
can anyone tell me where to get advice for this problem?

Again Thank you
cunndj
 






Back
Top