1985 B2 Low Acceleration code 83 and 87

[Mosier]

I have a 1985 B2 with a 2.8l V6 and a manual trans. Been trying to get it to pass emissions. After the emissions test I found the ECT sensor broken off, so I replaced that, before that I was having problems with the engine misfiring at operating temp, the new ECT sensor fixed that. Now that I fixed that problem I found that it is difficult for the truck to accelerate. I can barely get over 75 mph, let alone get to it. Just replaced fuel pump on the engine block due to low pressure from that, this fixed about 60% of the main problem, so I ran some codes and I'm getting 83 and 87. Truck idles a little high but evenly, doesn't stall or die out and accelerates reasonably in first gear, after that it's rough, flooring it doesn't rev it at all unless you're in first gear or high speed in 2nd or 3rd gear.


-Codes 83 and 87 KOEO
-New plugs/wires/cap/rotor/coil
-Put some high quality fuel cleaner in the tank about a week after I took the test and changed the ECT sensor, Gone through 2 fuel filters so far, those 2 clogged and engine wouldn't start, changing the filter fixed that.
-New Fuel Pump
-Newish Cat Converter (Took it off and drove around the block, not plugged)

*If anyone has any information on what to go after next and how to test it, would be greatly appreciated, thanks

 

[85broncduece]

sounds like carb or ign. timing or the elec. timing advance

 

[PetesPonies]

Check your EGR circuit.Pull the EGR valve and see if it is stuck. See if the vacuum diaphragm is still good. Make sure it is clean and nothing is keeping the valve from seating properly. 87 code is for the temperature compensator for the accelerator pump on the carb. They are lousy complicated carbs, those feed back types. But check the EGR first.

 

[Mosier]

Alright I'll try that and report back, thanks a bunch.

 

[Mosier]

ok so i pull off the egr valve and the pressure sensor and cleaned out the valve because it had a shit load of carbon deposit. Sprayed around the valve with carb cleaner along with the push rod inside. Since I had some carb cleaner left I went ahead and cleaned out the pcv, pumping it as i was spraying it. After that I pulled off the throttle linkage and pulled off the accelerator pump, seems to pump fine. I did notice that before i took the accelerator pump off i pumped the gas a few times and it shoots out a couple streams somewhere between 1/32 and 1/16 in thick. I checked this about 3 or 4 days ago and it was about 1/8 in thick of a stream coming out? So now after everythings cleaned up and put together, the truck accelerates even worse and backfires when I give it gas. I'm totally at a loss with this one? Any info on this would be helpful, thanks

 

[PetesPonies]

I don't see where you tested the EGR valve, just did some cleaning. If it is not working, especially stuck open, it will cause running issues. Did you apply vacuum to the valve?

 

[Mosier]

yes I tested the valve, it does open when under vacuum, it did seem kind of rough though. How smooth is it supposed to open?

 

[Mosier]

So I checked my EGR vacuum today while it was running and it barely gives any suction at all? I put my finger over it and it couldn't suction my finger onto it, it was about 20% of the suction that the vacuum line that goes to the vacuum motor.

 

[Brownie Mobile]

Im really glad i dont have to do emissions here, my B2 gets 6 mpg and is straight piped i feel like they wouldnt like that one too much im sure i put out enough carbon emissions for about 5 or 6 vehichles.

 

[PetesPonies]

The vacuum comes from the hose, is that what you tested? Vacuum doesn't come from the valve.

 

[Mosier]

yeah i was testing the hose, both at idle and higher rpm, stayed at a low suction the whole time. Will this be the position sensor on top of the valve or the control solenoid that the vacuum comes from? If it's the control solenoid, where would I get one? Can't find one on auto parts websites.


And Brownie Mobile, consider yourself lucky, emissions is a ****in pain in my ass, I'm about to go find a clunker pre 1976 vehicle in a yard somewhere and just put some collector tags on it.

 

[PetesPonies]

The control solenoid directs the vacuum. Make sure a strong vacuum is going to the solenoid. The computer tells it when to let the vacuum go to the EGR.

 

[Mosier]

yeah i was testing the hose, both at idle and higher rpm, stayed at a low suction the whole time. Will this be the position sensor on top of the valve or the control solenoid that the vacuum comes from? If it's the control solenoid, where would I get one? Can't find one on auto parts websites.


And Brownie Mobile, consider yourself lucky, emissions is a ****in pain in my ass, I'm about to go find a clunker pre 1976 vehicle in a yard somewhere and just put some collector tags on it.

 

[kimcrwbr1]

Did you reset the computer and erase the memory. Those vacuum lines get plugged over time as well as the solenoids on the passenger apron. To test the egr while the engine is running at an idle apply engine vacuum to the egr and the engine should stall.To clean the vacuum lines get a can of wd-40 and blast it through all the lines and blow them out with air pressure especially the one going to the bottom of the air horn to the carb. It goes to the air bleed for the egr, if you plug that vacuum line the egr will allways stay full open. It goes to the closest solenoid to the firewall make sure it is open and is pulling filtered ar into it that solenoid allows the egr to close. You cannot clean a PCV valve just put a new one with spark plugs as preventive maintenance. Also change the breather filter in the air filter housing. The valve on the front of the carb with the 90 degree vacuum fitting is the accelerator pump relief. The way it works when the computer open the solenoid it shuts off the accelerator pump. So clean all the vacuum lines with WD-40 and blow them clear make sure the egr bleed is pulling fresh filtered air in. Reset the computer and memory. Clean the intake air temp sensor in the air filter housing with electrical cleaner. Make sure everything is connected before you start the motor then run it for about 20 minutes at medium speeds and check the codes again. If you want to clean the four solenoids on the passenger side apron rig a couple jumper wires one for ground and the other for hot energize the solenoid and blast them with WD and follow up with air make sure they fully open and close with a chunk of vacuum line and suck as you energize the coil. If they dont fully close you may need another set of solenoids. GL

 

[kimcrwbr1]

http://www.therangerstation.com/tech_library/diagrams/1983vacuumhoseguide.jpg
The yellow vacuum line pulls filtered air in to close the EGR it plugs on to the fitting on the bottom of the air horn on the carb.