89 ranger starts but wont idle

[trouzp]

I bought this 89 ranger 4cylinder 4x4 5spd about 6 months ago it ran fine. Now just recently it wont idle, it surges really bad. Maybe a fuel filter? Ive had some people say maybe a temp sensor or throttle position sensor. Any other ideas or suggestions? thanks Travis

 

[chbtech]

Best thing to do is have the fault codes read. It should point you in the right direction.

 

[nova801428]

But, what if he can't pull them, then what should he do?

 

[glfredrick]

That's what a good scanner is for...

Check vacuum lines.
Check spark.
Change the fuel filter.
Make sure your pump is doing its thing (running Ford pumps below 1.4 tank eats their lunch!)
Test your ignition module (pull it and take it to AutoZone - free test and it is something they can actually do right).

 

[awood]

Based on the experience of a friend, if you DON'T have a CEL on, I would buy/borrow a fuel pressure test gauge made for fuel injection, and test for proper pressure. My friends truck would start, spew lots of black smoke, and die if he touched the throttle. The FPR fixed it. Apparantly it was dumping too much fuel pressure into the rail and causing the truck to flood, although I understand most failures are underpressure.

If you DO have a CEL, read the sticky's in this forum and learn how to pull the codes (if you don't know how already) and post the codes here.

 

[BrooklynBay]

Welcome to this forum! If your truck is able to idle only by holding the throttle pedal, then it sounds like the idle air control solenoid (Ford calls it the air bypass valve). If it keeps getting flooded, or is only hard to start when it is cold, then it might be the engine coolant temperature sensor (ECTS). The air charge temperature sensor (ACTS) gets fouled up by oil deposits, and could create a similar issue. You could take that part out, and clean it with fuel injection intake cleaner. Clean the throttle body at the same time.

 

[trouzp]

Hey guys thanks for the suggestions. I know its been a while I sort of had a family emergency come up and things got crazy........ I have another question about the fuel pressure......... I put a pressure gauge on it and it takes 4 or 5 times of turning the key on and off (priming the pump) before the pressure reached around 37 psi is this normal? Or should it go to 37 the first time you turn the key?????????????? Thanks again for your input Travis

 

[glfredrick]

Hey guys thanks for the suggestions. I know its been a while I sort of had a family emergency come up and things got crazy........ I have another question about the fuel pressure......... I put a pressure gauge on it and it takes 4 or 5 times of turning the key on and off (priming the pump) before the pressure reached around 37 psi is this normal? Or should it go to 37 the first time you turn the key?????????????? Thanks again for your input Travis

It should pressurize to the correct pressure with one pump cycle.

I'd start by changing the fuel filter, then testing again.

Next, you may need to change one of the two pumps -- one in the tank (a feeder pump - high volume, low pressure) or one on the frame rail (high pressure) in that order.

I'd also test the fuel pressure regulator, which can be tested with a vacuum pump (make sure it holds pressure) and a simple test is to just pull the vacuum line while the pump is running (if gas leaks out the vacuum port, the FPR is dead).

The fuel pump in the tank is very susceptible to low fuel levels in the tank. Running your tank below 1/4 full on a regular basis will eat pumps.

 

[trouzp]

Hey thanks....... the regulator holds pressure I havent seen another pump on the frame........ Do all of them have two pumps????? This a 4cylinder with dual plugs. which I couldnt believe................I have changed the fuel filter Thanks again for the help.............. travis

 

[awood]

Earlier models used two pumps. Your application may use only one. I'm not sure what year the change was made, but if you don't see a pump on the rail, then likely you have just the high pressure pump in the tank.

Do a search on the forums here...It seems like I read that it's easier to get some buddies and remove the truck bed, rather than dropping the tank to get access to the pump.

 

[glfredrick]

Earlier models used two pumps. Your application may use only one. I'm not sure what year the change was made, but if you don't see a pump on the rail, then likely you have just the high pressure pump in the tank.

Do a search on the forums here...It seems like I read that it's easier to get some buddies and remove the truck bed, rather than dropping the tank to get access to the pump.

What he said ^^^^^^ Exactly right.

Two people can pull the bed, quick work, just remember to unplug the light harness, and remove the small screws on the filler neck for the gas tank.

 

[trouzp]

Hey guys thanks for your help.......... Ill keep you posted.......

 

[Az_NavajoRob]

Did the dual-plug motor come out in '89? I thought that moter wasn't in the Ranger till later (like '95 and up). If somebody put that moter in then maybe they did something else that's causing the problem. I'd try looking at the mods they may have made.