90 Ford Ranger XLT 2.9 Crank no start

[toolagit2qwit]

90 Ranger XLT 2.9 Crank no start. Truck has 55k original miles. Turn the key it starts for 1 sec then stalls. If I keep pressing the gas pedal rapidly it stays running and once I stop it dies. At one point when it was running like it had a misfire then if I pulled vacuum hose off fuel regulator the truck ran great. Now it won’t stay started
- New Fuel Pump Sending Unit (30-35psi)
- New Fuel Regulator
- New Fuel Filter
- Checked all Vacuum hoses no leaks.
- Checked Relay all good
- Checked Fuel Kill switch. Good
- Throttle body is clean

I am out of ideas appreciate any guidance.
Thank you.

 

[SenorNoob]

Air filter?

 

[j-driver]

I'm not any kind of certified tech but it sounds like fuel starvation. Pulling the vac hose off the regulator would keep the regulator from dumping fuel into the return line.. clogged or stuck injectors? I just pulled the lower manifold off my '87 which had rebuilt injectors put in and then sat for a few years. Bench tested the injectors in the manifold and 4 of the 6 were stuck closed. Mine's only a few years older than yours, and mine died of fuel system rust more years ago than I want to admit to. New fuel filter didn't help.

 

[j-driver]

Some other people on this site have talked about hot wiring the main fuel pump to a manual switch downstream from the kill switch since it goes off a few seconds after you turn on the ignition, until the computer senses that the engine is running. Maybe something to try.

 

[toolagit2qwit]

90 Ranger XLT 2.9 Crank no start. Truck has 55k original miles. Turn the key it starts for 1 sec then stalls. If I keep pressing the gas pedal rapidly it stays running and once I stop it dies. At one point when it was running like it had a misfire then if I pulled vacuum hose off fuel regulator the truck ran great. Now it won’t stay started
- New Fuel Pump Sending Unit (30-35psi)
- New Fuel Regulator
- New Fuel Filter
- Checked all Vacuum hoses no leaks.
- Checked Relay all good
- Checked Fuel Kill switch. Good
- Throttle body is clean

I am out of ideas appreciate any guidance.
Thank you.

Are we able to attached a video?

 

[toolagit2qwit]

Anyone have ideas to share?

 

[rusty ol ranger]

Anyone have ideas to share?

Try cleaning your IAC?

Pulling the vaccuum hose allowed enough air in to keep it running at idle. This is assuming you didnt block the port and it runs with your foot on the throttle.

Also....pull the codes,

 

[Brain75]

I'm gonna point to the Chilton/Haynes on this one since we don't have a lot of troubleshooting so far, just throwing parts at it...
Section 7, engine starts but immediately dies.

 

[toolagit2qwit]

Try cleaning your IAC?

Pulling the vaccuum hose allowed enough air in to keep it running at idle. This is assuming you didnt block the port and it runs with your foot on the throttle.

Also....pull the codes,

I'm not any kind of certified tech but it sounds like fuel starvation. Pulling the vac hose off the regulator would keep the regulator from dumping fuel into the return line.. clogged or stuck injectors? I just pulled the lower manifold off my '87 which had rebuilt injectors put in and then sat for a few years. Bench tested the injectors in the manifold and 4 of the 6 were stuck closed. Mine's only a few years older than yours, and mine died of fuel system rust more years ago than I want to admit to. New fuel filter didn't help.

I’m getting 34psi at the rail. The regulator is new. No codes either. This only has 55k miles on it. Original engine. When I removed the MAP sensor (aka Manifold pressure switch) the truck idled and ran. Now I have a code because the MAP is off. I ordered a new MAP and will see. Thanks for the response.

 

[toolagit2qwit]

I'm gonna point to the Chilton/Haynes on this one since we don't have a lot of troubleshooting so far, just throwing parts at it...
Section 7, engine starts but immediately dies.

View attachment 129186

Thank you. I have a manual and scanned for codes. I’m going to toss in another part and that’s the MAP sensor. When disconnected the truck idled fine. Fuel pressure 34, no vacuum hose leaks etc. Truck is clean with low miles and my 1st issue with it. We will see. Appreciate the help

 

[toolagit2qwit]

Try cleaning your IAC?

Pulling the vaccuum hose allowed enough air in to keep it running at idle. This is assuming you didnt block the port and it runs with your foot on the throttle.

Also....pull the codes,
[/QUOTE
IAC is new All vacuum hoses checked and good. As mentioned below disconnect Ed the MAP and truck idles fine. I’m going to replace and see what happens. Scanned for codes and zero until MAP was disconnected- appreciate the help

 

[lil_Blue_Ford]

Moving this to the appropriate location

 

[Brain75]

"IAC is new" - did you test it before you put it on.... 50/50 chance of getting crap from parts stores now a days... might have put a new part on but didn't fix anything.

...have a youtube here give me a minute to find it..

... found one for the "no multimeter" style test - it takes a noid light though (it can be tested with a multimeter too - can't scare that vid up at the moment):

 

[toolagit2qwit]

90 Ranger XLT 2.9 Crank no start. Truck has 55k original miles. Turn the key it starts for 1 sec then stalls. If I keep pressing the gas pedal rapidly it stays running and once I stop it dies. At one point when it was running like it had a misfire then if I pulled vacuum hose off fuel regulator the truck ran great. Now it won’t stay started
- New Fuel Pump Sending Unit (30-35psi)
- New Fuel Regulator
- New Fuel Filter
- Checked all Vacuum hoses no leaks.
- Checked Relay all good
- Checked Fuel Kill switch. Good
- Throttle body is clean

I am out of ideas appreciate any guidance.
Thank you.

***UPDATE*** Truck is fixed! It was the MAP sensor (or Manifold Pressure Switch). 2 weeks ago the truck show small signs like a misfire at start up with inconsistent idle and lower power when driving. It slowly got worse like fuel starvation. Then it was hard to start and wouldn’t idle at all as mentioned above. Checked Fuel Pressure, vacuum hoses etc. Finally, I noticed a vacuum hose running into the firewall and connected just above left of the throttle body. Unplugged the electrical connection and vacuum line. Then started truck again and it ran and idled. So, I replace the MAP and it runs like new. Keep in mind no codes showed when scanned. Anyway, thank you all for your input and troubleshooting. Hopefully this helps others.

 

[toolagit2qwit]

***UPDATE*** Truck is fixed! It was the MAP sensor (or Manifold Pressure Switch). 2 weeks ago the truck show small signs like a misfire at start up with inconsistent idle and lower power when driving. It slowly got worse like fuel starvation. Then it was hard to start and wouldn’t idle at all as mentioned above. Checked Fuel Pressure, vacuum hoses etc. Finally, I noticed a vacuum hose running into the firewall and connected just above left of the throttle body. Unplugged the electrical connection and vacuum line. Then started truck again and it ran and idled. So, I replace the MAP and it runs like new. Keep in mind no codes showed when scanned. Anyway, thank you all for your input and troubleshooting. Hopefully this helps others.