leekainen

Just recently bought a 1987 F150 XLT Lariat with the 302. It's been sitting for quite some time and I've been trying to make it idle better and stop it from hesitating on acceleration. I've replaced the spark plugs, spark plug wires, distributor cap, rotor, ignition coil, fuel filter, and changed the oil. While replacing the ignition coil I noticed a part that I am not familiar with that is bolted onto the ignition coil bracket. Here's a picture of what I'm talking about.




It's right there on the side of the ignition coil

While changing the ignition coil, the front part with the two lines coming out of it fell off and a gasket and a flat metal disk dropped out of it. I've since used electrical tape to fasten it back in place because it's tabs broke off. I don't know if this could be causing my engine to idle rough or to hesitate on acceleration, so any help would be greatly appreciated. I've been thinking they might be vacuum lines but I'm not sure, I plan to replace all vacuum lines tomorrow. Hopefully that'll fix my problem.

leekainen

It's probably an easy question, I just don't have much auto experience

leekainen

After some more research, I believe it's the EVR, and the TAB and TAD are behind it. Could one of these things cause my rough idle problem? If so, is there a way to test them? Should I replace all of them if I replace one? Could really use some advice on this

Chris_1

iTrader: (1)

Those are electrically operated vacuum solenoids - so the computer can turn on and off components on the engine.
They have vacuum to them so a leak in one of the solenoids could cause a rough idle.
You could probably buy the whole coil bracket with all 3 solenoids for pretty cheap at the wreckers. If it's falling apart that might be an idea.

leekainen

I ended up ordering an EGR solenoid from auto zone, got it today but haven't had time to put it in yet. I did replace all the vacuum lines that i could. But when doing that, I noticed that the valves that the tad and tab connect to have been removed. The bypass valve and diverter valve. And I believe the smog pump has been removed as well. All I see is the alternator, ac assembly, crankshaft, power steering pump, and water pump. When I get home I'll probably try and plug the vacuum lines that went to the TAD/TAB solenoids, replace the EGR solenoid and see if that fixes my problem. Do I need to replace the valves and smog pump, solenoids, etc.? Or can run it with just the EGR solenoid and the vacuum lines plugged? I'm probably gonna try and clean the IAC and EGR valve as well.

Lazarus-F150

You may also want to look at the vacuum line to the A/C blend door actuator (near the firewall on the passenger side of the engine compartment). It has a white vacuum line that readily disintegrates and causes a vacuum leak. I replaced mine this weekend and had a very pleasant return of performance.

Sulli8888

That small white line was my vacuum leak problem too

24willyboy

how do you replace that vacuum line? I've heard of people slipping a larger line over the two disintegrated ends to fix it, but mine's so far gone it just crumbles to the touch, so that won't work for me. If I replace it i want to do it right and replace the entire thing

Lazarus-F150

1.) Pull the old line off of the A/C blend door and discard.
2.) Get some 5/32" vacuum line (from any auto parts store) and put it on the A/C blend door vacuum inlet (I secured mine with a zip tie just to be sure).
3.) Drill a hole on the plastic panel on the firewall behind the A/C blend door.
4.) Remove the glovebox and the passenger kick panel (will let you see the new vacuum line as you thread it in) and pull the new vacuum line through.
5.) Cut the existing white vacuum line (I cut it just upstream of a connector containing several vacuum lines) and thread the new line over the old line. I also secured this with a zip tie.
6.) Enjoy more consistent performance and max A/C function