It was mentioned that I should only have one thread so this is it. Due to a high rough idle (now about 975rpm at idle and rough) I just replaced the PCM with no help.

Here is what I have done so far: 1. New EGR and sensor 2. New MAP 3. New ICM 4. New IAC and sensor 5. Smoke test for leak twice (one leak found and fixed) 6.New water pump 7. New PS pump 8. New PCM 9. TB cleaned OOPS. 10. Timing reset with new PCM. 10. New Manifold gasket. 11. All new gaskets 12. Before I bought the truck the PO recently replaced the Distributor, Spark Plugs, Plug Wires and fuel Pumps etc. 13. Air filter replaced. ALL fluids changed. New brake pads and rotors.

These are the items that I think are still suspect. 1. Fuel Injectors 2. Smog pump bearing growling on start up occasionally. Info suggest a bad Smog pump can cause my symptoms but usually throws a code. I have NO KOEO codes. 3. Throttle body. 4. Coil 5. Plugs gaped properly. Before the PCM was replaced I was throwing the SPOUT OPEN code. It is gone with new PCM for now. 6. Bad Distributor or components? 7. PCV valve

There may be other things I have done but I think this is it for major parts.
I have a MM but I am electrically challenged but with explanation can do it. I have a CHILTON AND HAYNES manual. What would the informed do at this point to fix the high rough idle? Any help would be appreciated. Sorry for the long post but I needed to get it all in one Thread. Sandy

 

Definitely check distributor, if previous owner replaced with a cheap or rebuilt it could be bad, check spark, re-check resistance in teh spark plug wires. have you puled the plugs? what shape are they in?


Also hows the compression? what oil weight do you run?

 

Did it idle high or rough when you bought it, before you cleaned the throttle body?

 

That was first on my internal list. I have seen what the repair shop did to the PO. It was a one owner truck. It's not pretty what they did to the old man. He spent $5,000 in the last 5,000 miles before it sat up and then I bought it after his stroke . He couldn't shift anymore. The Dizzy they put on is probably the cheapest they could find. It could even be his old one cleaned up? Who knows.
Mobile 1 5w30 Wix filter. South Texas No compression test done.

 

Yes from day one. No compression test done.

 

Have you tested or replaced the Throttle Position Sensor? I know there is a video on YouTube on how to test it, and replace it, if you need the help for the ohms on the sensor. Just trying to help.

 

I will need to look at my list. I don't have it at the moment. If I haven't tested it, I will in the morning. Thank you and don't even think about the advise offending me. I really need all the help I can get.

Just looked at my list and I did check it and it was good.

One other point is, if I disconnect the IAC I have no change in idle. If I pull the vac line off the EGR there is no change at idle. Both of these components are new and I have tested them.

 

Next I would start looking for a vacuum leak in the throttle body gasket or the upper plenum gasket. also just for ****s and giggles pull the vacuum line off the fuel pressure regulator and see if there is fuel in it.

 

I was given an 89 F350 5.0 with a no start/no fuel pressure issue. The ECU was toast. I bought one from Cardone, the truck started and ran but had the same symptoms as yours. Turned out the ECU (rebuilt) was bad and there was nor power to the IAC or EGR. I found a thread somewhere here on how to check for voltage. Took it back and got another. Runs like a champ now.

 

No fuel in the FPR vac line. The TB and Manifold gaskets are new. I did see this connector that was not attached to anything and looks as though it has never been used. ??? Also the ground cable from the firewall to the Manifold is worn through. Could that be an issue??? Regarding the ECU, the same symptoms on the old one are the same as the new one. IAC disconnect no change.. disconect egr vac no change.

 

That looks like a fuel injector plug to me.

 

I was thinking the same thing when I looked at it earlier today...

The canister purge solenoid plug would be bigger.

 

I was thinking the same thing when I looked at it earlier today...
The canister purge solenoid plug would be bigger.

That looks like a fuel injector plug to me.


GOOD CALL It sure as hell is ^*&#*%^@#*#&.... That is a great lesson. Start with the basics which I didn't do. I honestly believe the PO's shop left it off. I did take the manifold off to change the VC gasket but I never got into the injectors, so I don't think I did it. Doesn't matter now anyway. Earlier I pulled the plugs and the one by the firewall was not tight. I KNOW I didn't do that.

When I was trying to plug the injector in I was disconnecting the vac line shown in the picture. While pulling the line the end pulled out under the manifold and I can't see where it goes. It also broke when I was trying to find the connection. I will need some hard vac line but can you tell me where it hooks up. I did start the truck and it is smooth as you can imagine. Idle is still high but I will look at the timing again (If you think I should), and of course it has a vac leak now. I will repair the line and see where I stand then.

Thanks so much guys for the help. I can't wait to repair the line and see what happens.

 

Just glad you found one of the main contributors to your problem. as for the vacuum line in the pic just take a pair of needle nose pliers and pull the end that broke off out and shove the hard line back in. Should be able to get by with that. my truck has a 302 so I can't help on the vacuum line origin until Monday when I go back to work. we got a 96 f150 with the straight 6 in it I can use to reference location on. does your truck still have the vacuum routing sticker?

 

I found the connection for the vac line. The line broke before the hook up and was buried under other lines. I have some line but it is to small and the short length that broke is to short to make the connection. I will pick some up tomorrow and replace the old line. Will let you guys know how it works out after that. Man I am stoked. Thank you Sandy