1986 Ranger 2.9 problems

[Rtmd1117]

I have a 1986 ranger 2.9. When i crank the engine it might fire once or twice but not start. or if it does start it will not idle and will run extremely rough. There is also A LOT of greyish/white smoke from the exhaust if it starts but it is not from coolant. I have replaced fuel filter, spark plugs, wires, distributor, icm, air filter, vacuum lines, and the fuel pressure regulator. Most of those were damaged in a flash fire hence replacing the unrelated parts. Any help would be appreciated.

 

[adsm08]

Fire you say?

Was any of the wiring damaged?

 

[RonD]

yes, melted wires would be my first choice.

After that:
With the engine cold, I would remove the rad cap and overflow tube.
Take a sandwich bag or latex glove and with someone turning over the engine, pinch the bag or glove over the rad cap hole for a tight seal and use your finger to plug the over flow.
If the bag or glove starts to inflate or dance a bit then you have a head or head gasket issue.
A cooling system has 0 pressure when cold, so the only place pressure could come from is the piston cylinder compression stroke and the only way it can get into the cooling system is through a cracked head or failed head gasket.
Simple test, even though you know it is "not coolant" it is worth testing.
The early 2.9 engines were known for bad heads, over heat once and get new heads.

Next I would test for too much fuel, pull out the fuel pump relay, I think it is the Brown one.
Pull off the air plenum(tube) on the intake, while some one tries to start the engine spray some "quick start" starting fluid into the intake, if engine starts up and can be kept running by the starting fluid then the fuel injection system is where your problem is.

If you still have the no start or it barely runs then problem will be in the spark/ignition system.

Timing chain/tensioner could be bad but would be low on the list with your symptoms

 

[Rtmd1117]

Yes the O2 sensor wiring and transmission wiring were melted but have since been repaired. I'll try the glove trick tomorrow and see what happens.

 

[Rtmd1117]

Okay well it started right up with starting fluid and the fuel relay pulled out. The glove trick confirmed it is not losing coolant. I'm thinking fuel injectors?

 

[RonD]

Good deal about the head/gasket being ok.

Could be clogged fuel filter, $15 replacement cost.
But this issue is usually noticed with power loss at higher speeds, starving for fuel, and start up and idle are fine.

Injectors can be tested for resistance, but it sounds like you have more than one having a problem so I would tend to look for a system issue not an individual injector issue.
The fuel pressure regulators on these engines/rangers did have problems, stuck open or leaked, and that would fit with your rough start and smoke in exhaust.
Unfortunately these can only be checked with a gauge.
Fuel pressure should be 29-32psi at idle, if engine is reved up it should go up to 38-40psi, if 50psi or above regulator is bad.

The fuel regulator has a vacuum line connected to it, if the regulators diaphragm leaks this line will have fuel in it, and floods the intake, remove the vacuum line and check it for fuel.

 

[Rtmd1117]

Good deal about the head/gasket being ok.

Could be clogged fuel filter, $15 replacement cost.
But this issue is usually noticed with power loss at higher speeds, starving for fuel, and start up and idle are fine.

Injectors can be tested for resistance, but it sounds like you have more than one having a problem so I would tend to look for a system issue not an individual injector issue.
The fuel pressure regulators on these engines/rangers did have problems, stuck open or leaked, and that would fit with your rough start and smoke in exhaust.
Unfortunately these can only be checked with a gauge.
Fuel pressure should be 29-32psi at idle, if engine is reved up it should go up to 38-40psi, if 50psi or above regulator is bad.

The fuel regulator has a vacuum line connected to it, if the regulators diaphragm leaks this line will have fuel in it, and floods the intake, remove the vacuum line and check it for fuel.

Well i got a fuel pressure gauge from autozone, turns out the fuel pressure was at about 100 psi. Gonna order a new regulator from rockauto and hopefully have a running ranger again

 

[Rtmd1117]

Finally got the regulator. Now she starts but runs terrible at idle, and stumbles badly under light acceleration. Seems to run fine under harder acceleration or at WOT......

Any ideas?

 

[PGHFord]

What happens if you unplug the electrical plug on the MAP sensor? Since you got the same year as mine, it should be located between the air box and inside fender, color either black or gray, has a vacuum line attached to bottom and a electrical plug next to it. It looks sorta like a popsicle without a stick at the bottom thats how I refer to it to people so they can find it. LOL

 

[PGHFord]

The other thing is to, if you replaced fuel filter did you replace both of them? Not just the one on the frame up by the engine, there is one located between the frame mounted main pump and the pump in the gas tank, its located in a black plastic housing, the fuel lines attach to it. There is a filter in there, or maybe someone removed it at some point. How I get to mine is take a oil filter wrench and unscrew the cap, if you remove the bolts on the outside of the frame that attach the metal bracket that holds it to it it sorta swings out some so you can get a little better access to it, but be careful, being an old truck, go easy dont want to crack fuel lines ya know? LOL when I reinstall it I take some hi tack gasket sealer lightly go around the inside of the plastic cup to hold that very fine lip seal to it they give you with a new filter.

 

[PGHFord]

oh and remember when you reinstall that other can filter make sure the seal open part of the filter is facing up, closed metal side down, dont want to install it upside down.

 

[Rtmd1117]

MAP sensor makes no difference plugged in or not. I'm assuming that's a problem lol.

And yes both fuel filters were replaced.

 

[PGHFord]

my motto, when in doubt switch it out. LOL 99% percent gut/instinct fixes the problem, most of the sensors and IACs, MAPS, are not as expensive as they once were, pretty cheap now a days. And if your running with OE that came with the vehicle, probably a good time to switch up.

 

[Rtmd1117]

Yeah I will probably replace the MAP and see if that fixes things

 

[PGHFord]

I went out and bought a new MAP and IAC for mine, have taken my old ones and broke down the map to expose internal and it looks like I dont know if on all IAC's you can remove the valve body from the solenoid if you wanted to do a deep soak cleaning of the valve body, there is oring gasket between solenoid and valve body only and was just two screws holding solenoid to it. I posted the pics in my ablum if anyone wants to see.