87 2.9 electrical problem....

[Erronh12]

just bought a bronco II but it didn't run. got it home charged the battery and it started but idle was extremely rough. and when i would press the gass it seemed like it wasn't getting any fuel. ran for about 5 min then quit. i went ahead and replaced the plugs, wires, D-cap and R-button and still could not get it to run. i was messing around with the wire that that runs from the coil to the distributer cap while a buddy was trying to turn the motor over and as a slowly pulled the wire off of the distributer the motor would start to run but idled extremely rough. As soon as i pushed the wire back onto the distributer cap the truck would shut off. I have no idea where to go from here...

[tekatlarge]

Got any codes? Got any fuel pressure?

[Erronh12]

no codes. and i do have fuel pressure. worked on it all day today. not sure if a have enough fuel preasure though. how much should it have. i can't find anywhere or anybody that knows exactly. i did replace the fuel pres reg today and it fired up and would idle and rev. checked with a timing light and it is in time. but as soon as i would put it in gear and pressed the gas it would die...

[Ranger Dave]

TPS

[Erronh12]

Okay thank you. I was going to check that. What about the EGR and the MAP sensor?

[Erronh12]

checked map sensor and egr. both are good. tps is good. i think the pig tail that connects to the ignition control module may have a short or one is grounding out. is it hard to replace?

[tekatlarge]

Fuel pressure should be about 45psi

[Erronh12]

fuel pressure is good...I'm lost have no clue where to go from here. has anyone ever had the ECU go bad? Had a buddy that was having the same problem with his F150 and that's what it ended up being.

[Erronh12]

replaced the ignition conrtol module and the contacts in the dist. runs good. if anybody else is having problems like mine make sure when you have the ignition control module cheked that they test it several times because it has to be warm in order to get a accurate reading. it will sometimes test ok if it is cold.

[tekatlarge]

Here is a little tip concerning testing the TFI and other parts.

If you have your parts tested at a shop or store take a hair dryer with you. I mean a hand held gun type. Use the hair dryer to slowly heat the component under test. This will pick up 99.99/100 of a percent of failures that are thermal in nature and that is usually the type of failure that these testers will never show. Caution!!!! Do NOT melt the part or get it hotter than you can touch!

The store testers are pretty elementary in design and will not really load the module up enough to generate heat to show a fail but heat with a hair drier and it will show the fail.

Glad to see your back in business

[Erronh12]

thanks for the tip. thats what i get for listening to advanced auto. it took a little research but i got to the bottom of it. i'm now having a problem with it missing under load. it will run good when im cruising down the road with my foot barely on the gas but as soon as i slow down to make a slow turn and then get into the gas a little or pull up to a stop sign it wants to die unless i floor it. the exhaust is cut right behind the muffler. could this be causing the O2 sensor to get a bad reading and causing my problems.

[joeyy]

I dont have any exhaust on it past the headers, my O2 sensor hd the wires severed for some reason awhile back, so i redid them, i think it works, but that could also be y im getting horrible gas mileage. i thought i would just put in my 2 cents

[Erronh12]

i was just informed that there is a plug that has to bed disconnected inorder to time the moter. place the motor at TDC time with the dis and timing light. turn off the engine. plug everyting back together and the computer does the rest??? is that accurate?

[KRE]

Disconnect the Sprout. plug, start the engine an set timing to spec. Shut down engine and reinstall plug, computer takes it from there.

The S. plug is just to the rear and below the idle air motor, on the intake man.

[Erronh12]

thanks runs great. i have the push button 4x4 yeah shitty and it's not working. how hard is it to swap out the transfer case for a manual 4x4.