4.1 Buick/Caddy motor issues

[Angry Matt]

I posted this in the wrong section, I don't mean to repost but I don't know my way around here so I'm copying this here.

Just bought an '81 Cadillac with the optional 4.1 252 Buick motor. I've been asking for help on the Caddy forums, but with it not being a common motor in these cars there's not too many Caddy guys with them so I was hoping I could get some help here. The car ran fine for the first two weeks I owned it. Wanted to do a little pm, so I put new plugs in. AC Delco factory spec. The next day the car sputtered during acceleration, bad. Thought I damaged a wire, so I replaced them, no change. Got new plugs thinking I had a bad one somewhere, no change. Fiddled with the EGR vacuum solenoid and it got much worse. Noticed one of the nipples on the solenoid was broken, so I fixed it, got a little better. Unplugged the EFE, because it was unplugged when I got the car, and it didn't make a difference. Checked the timing and it's around 20. I can't find any broken vacuum lines. I'm confused and frustrated. I just want it to run smooth.

 

[charlief1]

I'm gonna guess the EFE is the plate under the carb. If this is the case get a new gasket and get rid of it. Most of the time they burn out and cause problems so start there. After this get a can of carb cleaner and spray around the engine top to make sure you don't have a vac leak. You'll know if you have one if the rpm increases. Does the check engine light come on?

 

[Angry Matt]

Good chance there's no bulb in the check engine light plug. It doesn't come on at start up. The efe is a flap that covers the exhaust? I've been trying to understand it via the shop manual. It recirculates hot air for quicker temp increase when the car's warming up. What's under the carb I can get rid of? I love gutting and simplifying everything, but I need this to pass emissions so I've been careful as to what I touch.

 

[charlief1]

EFE= Evaproitive Fuel Emission Some of the exhaust manifolds have a flap in them which restrict flow to increase the engine temp and reduce emissions. See if there's a a couple of wires under the carb. Some of the 4.1's came with a heater plate under them which is called an EFE heater. If it does repace it with a regular gasket.
Check the bulb in the check engine light and make sure it good. If not, replace it so ou can get codes out of it if there are any.

With the engine running you should be able to get to the EGR valve. See if it moves up and down freely and if it does, it should bog the engine down when you move it.

Get some carb cleaner and with the engine running use the extension and spray it around the top to check for a vac leak. If the engine RPM increases in a specific location then you need to lok at all the vac lines ect carefully.

 

[Pronto]

Good chance there's no bulb in the check engine light plug. It doesn't come on at start up. The efe is a flap that covers the exhaust? I've been trying to understand it via the shop manual. It recirculates hot air for quicker temp increase when the car's warming up. What's under the carb I can get rid of? I love gutting and simplifying everything, but I need this to pass emissions so I've been careful as to what I touch.

My friend's T had no Check light. Turns out someone popped out the socket from the dash so it wouldn't shine at them.

 

[Freddie's Buick]

Take a pic of the engine bay concentrating on the the carb, EFE, EGR.
We just love pics....

That helps solve having to guess the type of emissions system you have.

Although being an 81' I know what it used. The later ones were very differant. 81' was a one year run and some of the guys here get confused generalizing with the later sytems.

 

[Angry Matt]

I think it's fixed. I got rid of the egr vacuum solenoid and plugged the egr valve. Capped all the lines that aren't being used and it runs WAY better. I think it was that solenoid. It all but crumbled in my hands when I fiddled with it. Here's some pics of the solenoid, I'll get some of the motor next time I'm working on it.

I've got to say, I've never owned a Buick before and I'm really surprised how it gets this heavy Cadillac moving like it does.

 

[charlief1]

Glad to here you figured some of the problem out. You should enjoy it for a while until you decide to add some more power. Not hard to do either.

 

[Angry Matt]

until you decide to add some more power. Not hard to do either.

Got any suggestions on where to start? Something simple to think about for the future. I've got an '81 coupe deville with a '70 472 in it, I've been working on it for close to 10 years. I don't know if I'm ready for another project.

And it doesn't have the EFE plate, it has it on the collector.

 

[charlief1]

Here's a start for you. http://www.turbobuick.com/forums/be.../281474-modification-4-1-4-barrel-intake.html
I outlined as much as I could so you guys can do it if you want to. A slightly larger cam and maybe headers or you can get the draw through carb/turbo set up. The last one should work well if all your computer controls are working right.

 

[Freddie's Buick]

I think it's fixed. I got rid of the egr vacuum solenoid and plugged the egr valve. Capped all the lines that aren't being used and it runs WAY better. I think it was that solenoid. It all but crumbled in my hands when I fiddled with it.....

That is a unit that consist of three selonoids, (one is an EGR selonoid). One controls the EFE on the drivers side exhaust and the other is to purge the canister system.

I have that system and sadly it does crumple down to dust eventually. But you ripped it out so I'd eventually get rid of the air pump and all thet other useless crap that the 80's emissions Nazis pumped those cars with.

 

[Freddie's Buick]

One thing I forgot to mention. The one selonoid that controls the EFE. The flap will not open anymore on the heat riser valve in the drivers side exhaust.

You'll have to figure out a way to cause it to open or you're going to have problems. Connect it back up. This is how it works:

When the engine is cold the selonoid does not allow vac to get to the flap causing the the engine to warm up faster. Once it warms up, the selonoid allows vacuum and the flap stays open. It's controled by the ECM.

Mine works so I kept it working along with the canister selonoid. The only one that does'nt work on mine is the EGR.

 

[Angry Matt]

Can I just tee off a manifold or booster vacuum line to hold the efe open? I was hoping it was open without vacuum, not closed. They should have made it the other way around. Maybe I can take the unit out all together? If it just will unbolt and I can bolt the pipe back together I could do that no problem. It will run fine without it, just takes longer to warm up, right?

eventually get rid of the air pump and all thet other useless crap that the 80's emissions

One day this thing will have to pass emissions. I'm driving with NJ state inspection right now that is still good but was supposed to be reinspected in PA 10 days after I bought the car. It's been almost 30...

 

[Freddie's Buick]

Can I just tee off a manifold or booster vacuum line to hold the efe open? I was hoping it was open without vacuum, not closed. They should have made it the other way around. Maybe I can take the unit out all together? If it just will unbolt and I can bolt the pipe back together I could do that no problem. It will run fine without it, just takes longer to warm up, right?...

Oops...Yep... disconnected it remains open not closed...my bad sorry!

Yes, it will take the motor a lot longer to warm up to operating condition on cold NJ days. :biggrin: