86 GM 5.0 with bad miss/sputtering/jerking. some Help would be nice

[sly]

condensation would cause that... or bad gas (water in gas). At least that's my thinking... definitely dump out the canister (probably need a new one) and see if you can get at the rear of that vent line to purge the water out of it. There should be a rubber hose from the hardline to the top of the tank.

[sly]

also... check to see if the caps are on the open holes (if any). rain water can potentially drain down into that thing if the hoses/caps are not in place.

[meandad]

There are 2 uncapped openings on the top (doesn't look like they ever had caps) , but the whole thing is under the battery tray pretty safe from the rain. I couldn't suction the water out of the steel line either. I was thinking of blowing it out but I have to know what it connects to on the tank side. The purge solenoid appears to be shot also. Nothing is going right on this job.

[gadget73]

I was also thinking condensation. There is a one-way check valve in the top of the tank that the line connects to. I don't think you can blow that back into the tank. I wouldn't advise it anyway. Water in the fuel never helps. If you can get your hands on a vacuum pump with one of those brake bleeder cups, hook that up and pull some vacuum on the line to clear the moisture out. The charcoal can being full of water might mean the vac solenoid never opens to pull the fumes and such out. It shouldn't be able to hold that much moisture in it unless its been sitting quite a while.

[miamibob]

Is there a charcoal cannister on an '87 GM? If so, where is it????

[sly]

I was thinking to disconnect the canister and the tank and blow the water out of the line.

the EFI canisters are typically located directly UNDER the battery.

[miamibob]

Now I'll have to have a peek - just for grins! Never bothered thinking about it as the car has always run well but nice to know about it's location and purpose as good things never last forever! Thanks for the info.....

[meandad]

Mine is under the battery tray, You can take it out from underneath. Just 2 Bolts. I finished putting the top half of the engine together with all new vacuum lines. Found a couple squishy ones that I was hoping were the cause of my hesitation/stumbling problems. No luck. Runs the same as it did before. At least I found out why the valve covers were leaking. I could take the bolts out with my fingers. I also extended the wires that go to the O2 sensors so I could actually get at them if I decide to change them. Was going to try changing the speed density sensor next. Not necessarily because of it's likely to be the problem, but because it's now become the cheapest option. I'm open to any suggestions

[meandad]

Mine is under the battery tray, You can take it out from underneath. Just 2 Bolts. I finished putting the top half of the engine together with all new vacuum lines. Found a couple squishy ones that I was hoping were the cause of my hesitation/stumbling problems. No luck. Runs the same as it did before. At least I found out why the valve covers were leaking. I could take the bolts out with my fingers. I also extended the wires that go to the O2 sensors so I could actually get at them if I decide to change them. Was going to try changing the speed density sensor next. Not necessarily because of it's likely to be the problem, but because it's now become the cheapest option. I'm open to any suggestions

Just ordered a new purge solenoid and 2 O2 sensors. Going to try them next (now that I can get at the connectors for the O2 sensors. Tried disconnecting them on some old advice, and the car runs worse so they are doing something, I just don't know what.

[meandad]

Well, I replaced the VSS sensor, and it did nothing as I thought. I replaced the bad purge solenoid which also did nothing but I knew it was bad. I've been spraying my O2 sensors with PB blaster for the past couple days with the intention of replacing them come Friday. I tried to plug in one of the new ones, but the connectors only go in half way. It's like they are the same, but different. They are Ultrapower OS 234-3001, and are supposed to be a direct replacement. The wire color code is the same. Has anyone had similar problems ? Are there different ford connectors that look the same ?

[meandad]

Well I found out there was nothing wrong with the connectors on the O2 sensors. They just needed a little goose grease to get past the O rings. The old O2 sensors came out after a little struggle, and didn't look half as bad as I thought. A little carboned toward the ends, but mostly a nice tan color. I have noticed no difference after changing them, but I'm hoping the computer is still in the process of adjusting. Keeping my fingers crossed cause I seem to be running out of things to change or do.

[1990LTD]

When you changed them did you disconnect the battery?

[meandad]

Nope. I thought I would let the car adjust to them. Now instead of a code 11, I get codes 41 & 91. Maybe I'll try disconnecting the battery Tomorrow. I have a feeling, I am back to square 1 again.

[gadget73]

41 and 91 indicate a lean condition. usually its a good idea to reset the ECM's learned data when you replace sensors, especially ones that will monkey with the fuel trim.

[sly]

+1 reset the computer when replacing sensors. You want to always make it re-learn what to do since not all sensors are created equal.