What is this part?

[Kmcbride3956]

Can anyone tell me what this part is? It’s a sort of rectangular black plastic part mounted in the engine bay on the firewall, has an electrical connector and a vacuum line going into it. It’s on a 1988 Ranger. I keep trying to upload a picture but it says my picture is to big.

 

[Kmcbride3956]

Finally got a picture that would load

 

[Kmcbride3956]

Couple more pics

 

[Nez'sRanger]

That is a MAP sensor.

 

[Kmcbride3956]

Thank you very much. I was given this truck and it has no spark so I’m going through all the tests and noticed that the wires to the map sensor were all cut.

 

[Curious Hound]

Has the engine been swapped? Some systems use a MAP sensor and others use a MAF sensor. Two different ways to tell the computer what's happening in the intake system. If the engine has been swapped, the new one might be using MAF instead.

 

[Kmcbride3956]

No, it’s the original engine. I think that when someone was trying to figure out the no spark condition they messed up the wires to the map sensor. It’s got a few areas with bad wiring. I’m going to replace the ICM and PIP sensor and see if it will crank. If not I suppose it’s off to the scrap yard. I really want to make this truck run, but I can’t see putting much money in it.

 

[adsm08]

Take a non-powered test light and run it between the battery positive and the green wire at the ignition coil. It should flash with the engine cranking.

If it does, check for key-on power on the other wire. If it doesn't check for key on power to the TFI module.

If you actually sit down and diagnose instead of throwing parts at it you can probably fix this for under $100. A few years ago I bought a real clean truck for cheap because the guy couldn't make it run. I hauled it home, spent one hour testing things, $20 on parts, and have driven that engine and wiring in a different vehicle for almost 20K miles, used the body for a different project.

 

[rusty ol ranger]

No, it’s the original engine. I think that when someone was trying to figure out the no spark condition they messed up the wires to the map sensor. It’s got a few areas with bad wiring. I’m going to replace the ICM and PIP sensor and see if it will crank. If not I suppose it’s off to the scrap yard. I really want to make this truck run, but I can’t see putting much money in it.

If its not rusted in half its worth spending money on (or selling to someone who will).

Dont just scrap it.

The wires are color coded, it should be pretty easy to splice new wires. But one things for sure its not gonna fire with the map wires all cut.

It was pry a TFI that went out and someone just started yanking things and got in over their head

 

[Kmcbride3956]

Yes, that’s exactly what happened and why I got it for free. Someone (brother in law) got in over his head and just gave up on it. I’m going to repair all the wiring that I can see is messed up and go from there. It’s a solid rust free little truck been in Georgia it’s whole life. I’d really like to get it going again.

 

[Kmcbride3956]

Take a non-powered test light and run it between the battery positive and the green wire at the ignition coil. It should flash with the engine cranking.

If it does, check for key-on power on the other wire. If it doesn't check for key on power to the TFI module.

If you actually sit down and diagnose instead of throwing parts at it you can probably fix this for under $100. A few years ago I bought a real clean truck for cheap because the guy couldn't make it run. I hauled it home, spent one hour testing things, $20 on parts, and have driven that engine and wiring in a different vehicle for almost 20K miles, used the body for a different project.

I will try testing the coil and tfi after I fix the cut wires that I see on this thing. I was just going to replace the TFI because I know how troublesome they can be and the one on it is some aftermarket made in China part, so I wanted to put a motorcraft one on. I figured if I end up not being able to make the truck run, I could sell the motorcraft tfi on eBay! But I suppose with enough time and testing I should be able to make it run.

 

[rusty ol ranger]

Yes, that’s exactly what happened and why I got it for free. Someone (brother in law) got in over his head and just gave up on it. I’m going to repair all the wiring that I can see is messed up and go from there. It’s a solid rust free little truck been in Georgia it’s whole life. I’d really like to get it going again.

You may be able to source a good wireing harness here or in a junkyard....just a thought.

 

[Kmcbride3956]

Take a non-powered test light and run it between the battery positive and the green wire at the ignition coil. It should flash with the engine cranking.

If it does, check for key-on power on the other wire. If it doesn't check for key on power to the TFI module.

If you actually sit down and diagnose instead of throwing parts at it you can probably fix this for under $100. A few years ago I bought a real clean truck for cheap because the guy couldn't make it run. I hauled it home, spent one hour testing things, $20 on parts, and have driven that engine and wiring in a different vehicle for almost 20K miles, used the body for a different project.

Okay I tested it and it doesn’t blink when turning over the engine. When I checked the red wire going into the coil, with the test light on the negative terminal of the battery, it does have power. So you think the TFI is bad?

 

[adsm08]

Okay I tested it and it doesn’t blink when turning over the engine. When I checked the red wire going into the coil, with the test light on the negative terminal of the battery, it does have power. So you think the TFI is bad?

It looks that way. At the very least the signal from the TFI to the coil to fire isn't getting to the coil. That's what that test was for,.