Hi all, this is my first post here and I have been soaking up a lot of information from this forum to work on my new to me 96 80 Series. It has 214k miles and I bought it from the original owners at the beginning of this year, I have been struggling with it since the day it came home.
It has a random hesitation/stumble/almost stall, whatever you want to call it. By random I mean very random. Sometimes it will happen at idle, some times cruising speed, sometimes at low acceleration. Sometimes I will drive and there will be no hesitation what so ever and it is like nothing is wrong. I would say when it does hesitate it is mostly at low throttle, so as I ease onto the gas from a stop it will drop RPM and almost want to stall. It also will do it at idle, and sometimes when I am at cruising speeds. Only twice has it actually stalled completely out, and that was when I was going in reverse very slowly, but I have been in reverse slowly many times and there has been no issue. I do feel like it shifts late sometimes but it is hard for me to tell if that's normal cause I don't have much experience driving an 80.
It also had the P0401 code. I followed a post on here and replaced everything (hoses, vsv, egr modulator, and cleaned the intake and throttle body)I also replaced the fuel filter, PHH, other water hoses while I was there, fan blades, and fan clutch, exhaust donuts, thermostat, and flushed the coolant. The P0401 code went away but this hesitation still remains.
Here are a list of the things I checked:
I am at a loss here and I have read scrolled through multiple searches of 'random' 'hesitation' 'cor' 'fuel pump' 'stalling' but no post was exactly my problem and I am still not sure which direction to go.
Will the community please help this poor soul, I am willing to do what it takes just need some guidance. I want to diagnosis and figure out not just start throwing new parts at it, all the parts I have been buying are OEM, so fuel pump and new wires will be quite expensive and I will be nowhere closer to figuring it out if those aren't my solution.
It has a random hesitation/stumble/almost stall, whatever you want to call it. By random I mean very random. Sometimes it will happen at idle, some times cruising speed, sometimes at low acceleration. Sometimes I will drive and there will be no hesitation what so ever and it is like nothing is wrong. I would say when it does hesitate it is mostly at low throttle, so as I ease onto the gas from a stop it will drop RPM and almost want to stall. It also will do it at idle, and sometimes when I am at cruising speeds. Only twice has it actually stalled completely out, and that was when I was going in reverse very slowly, but I have been in reverse slowly many times and there has been no issue. I do feel like it shifts late sometimes but it is hard for me to tell if that's normal cause I don't have much experience driving an 80.
It also had the P0401 code. I followed a post on here and replaced everything (hoses, vsv, egr modulator, and cleaned the intake and throttle body)I also replaced the fuel filter, PHH, other water hoses while I was there, fan blades, and fan clutch, exhaust donuts, thermostat, and flushed the coolant. The P0401 code went away but this hesitation still remains.
Here are a list of the things I checked:
- Wire Harness Next to EGR Pipe: i removed the old tape and checked the wires, they looked good, i rewrapped it with 3 layers of protection.
- The MAF wiring harness, and I cleaned the MAF with MAF Cleaner
- I tried to jump the fuel pump circuit but when I jumped the +B to the Fp. I heard no noise like I was expecting, like a pump turning on with the key in the 'ON' position.
- I removed the fuel pump to check it out, it is not OEM but appears to be clean and recently replaced, the sock looks great too.
- I opened the distributor and replaced the rotor and cap, there was some oil in the distributor which I cleaned off with electric parts cleaner.
- There was also some oil in the #1 cylinder, but I was told that the valve cover gasket was recently replaced, and it appears to be replaced properly, just no OEM spark plug wires.
I am at a loss here and I have read scrolled through multiple searches of 'random' 'hesitation' 'cor' 'fuel pump' 'stalling' but no post was exactly my problem and I am still not sure which direction to go.
Will the community please help this poor soul, I am willing to do what it takes just need some guidance. I want to diagnosis and figure out not just start throwing new parts at it, all the parts I have been buying are OEM, so fuel pump and new wires will be quite expensive and I will be nowhere closer to figuring it out if those aren't my solution.
