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Close analogy, but I think it's more like going to the doctor due to dizzy spells. That could be caused by low blood pressure. But without even checking blood pressure, the doctor goes straight to a heart transplant.
The preceding was industrial strength satire. We're all trying to get you to slow down, that's all. The other option is we break out the forum's tranquilizer dart gun. It's a lot of fun and all, but those darts are expensive.
In your latest post, you mentioned the lights are fluctuating bright and dim. You weren't very specific, but are they following engine RPM or fluctuating on their own? Either way, this is once again a YUGE clue. Wish you would have mentioned this earlier. If you don't have a voltmeter yet, put on a ski mask, knock over a liquor store, and use the proceeds to buy a $7 meter at Harbor Freight. Pick up a battery charger while you're in there. Keep the ski mask on so nobody sees you shopping there. But for goodness sake, charge that poor battery, check the stinkin' alternator output, and report back. From your very first post in this thread when the starter wouldn't spin the engine, it sounds like your battery has been run way down. Remember, a depleted battery can self-recover to some extent after sitting for several hours, so the fact that it restarted the next day does NOT mean all is well. And please, oh please, do not rush out and buy a new battery, starter, ignition switch, etc. We can walk you through how to test those components if needed.
Fix one thing at a time and then retest. You may very well have a vacuum leak at the brake booster. Sounds like your spark plugs are shot, too. I bet the plug wires are on their last legs. Maybe a mouse has built a nest inside the carb, too. All in due time. Troubleshooting 101: Fix the known faults first, even if you think they aren't responsible for the present symptoms. And if you do suddenly feel a quick, sharp sting, please don't pull out the tranquilizer dart. It's for your own good.
Dimming brightness of all lights I inside and out does follow the rhythm of idle and rpms. Another interesting thing I noticed.. idle now in park is ok (not great) but drops in drive, rev, and low gear but not in neutral or park.
Multimeter and battery charger is on the way. Tracking says Monday delivery. Ordered a few days ago.
One more thought: If you're just beside yourself waiting until Monday for the charger, take your battery to any place that sells batteries. They will typically charge and test it for free:
One little caveat - make sure you request that the battery gets charged. Most stores use hi-tech testers that can determine the overall battery health (not just state of charge) without the need for a full charge first. If you just drop it off, word may not get to the guy running the tester. He may not realize you also want it charged.
If they tell you the battery is toast, by all means get a new one. But if it passes, there's no need to replace it unless you've got money burning a hole in your pocket.
Last edited by kr98664; Sep 14, 2019 at 02:36 PM.
Reason: fixed typo
Lights dimming and brightening &c is a voltage regulation problem by definition. Need to get that fixed because it will start blowing headlights out among other things. Btw, has the engine or transmission ever been swapped out? Make sure that the ground strap cables to block, frame, and firewall aren't missing, corroded, or loose. Not saying this is your problem but weird stuff starts happening when there are ground issues.
Lights dimming and brightening &c is a voltage regulation problem by definition.
Good point, but a little RPM-based change is normal. I wonder how much variation he's really got. It will be worse if the battery is run down or in poor health. Voltage readings here (idle and 1500 RPM) would be very helpful.
Lights dimming and brightening &c is a voltage regulation problem by definition. Need to get that fixed because it will start blowing headlights out among other things. Btw, has the engine or transmission ever been swapped out? Make sure that the ground strap cables to block, frame, and firewall aren't missing, corroded, or loose. Not saying this is your problem but weird stuff starts happening when there are ground issues.
From what I understand the engine is original as is the transmission. It looks that way visually as well. That being said I’d love to go through and check grounds but I really have no clue where to start or what they are even supposed to look like. Would need some visual help with pictures or video on that.
I’d love to go through and check grounds but I really have no clue where to start or what they are even supposed to look like.
Trucks and cars use the metal body and frame and other steel parts as "wiring" for the electrical return path or ground. So anywhere you see a cable or strap bolted to the frame, or the engine block, or the block to firewall, that's a negative ground path back to the battery. They are important, and as they corrode start to reduce voltage and current. In fact if they are original or just old they should be replaced with good quality heavy gauge cables. They start to interfere with starting, charging, and ignition. Often overlooked on engine swaps and the like and can cause trouble.
So I completed the tune up yesterday with the exception of the rotor. The one I got didn't fit so I'll pick up another asap. That being said.. the spark plugs on this thing were a mess Most of them were black and or burnt up. Definitely had some oil deposits which I guess is expected on a motor with 170k miles on it. The connections on the distributor cap had some brown build up and carbon as well. Also did an oil change and added some trans fluid as it was pretty low. Anyways, I replaced the plugs along with wires and cap. Seems to definitely help smoothed things out but Ive yet to take it on a short trip. It's not stalling out anymore but the idle in drive was still little low.. like maybe 400 rpm. For now I just adjusted the idle screw up a tad and it's idling in park at around 850 rpm and maybe 500-550 in drive. Only things I'm still noticing is little surging of rpm's at times at idle. Not all the time but some times it jumps repetitively about 100 rpm which is annoying. Still some pulsing of inside and outside lights but does seem improved after the new alternator and regulator. I don't think the issue is completely solved but I think the tune up made a noticeable improvement. I think the brake booster needs to be replaced still b/c it does hiss when pedal is pressed. As you guys have mentioned I suspect there still could be a carb issue or vacuum problem that I hope to figure out. I also do want to still check the battery when my charger arrives and the voltage when the multimeter arrives. That being said the only thing truly eating me at the moment is the intermittent surging. Will report back after I give it a decent test drive.
So I completed the tune up yesterday with the exception of the rotor. The one I got didn't fit so I'll pick up another asap. That being said.. the spark plugs on this thing were a mess Most of them were black and or burnt up. Definitely had some oil deposits which I guess is expected on a motor with 170k miles on it. The connections on the distributor cap had some brown build up and carbon as well. Also did an oil change and added some trans fluid as it was pretty low. Anyways, I replaced the plugs along with wires and cap. Seems to definitely help smoothed things out but Ive yet to take it on a short trip. It's not stalling out anymore but the idle in drive was still little low.. like maybe 400 rpm. For now I just adjusted the idle screw up a tad and it's idling in park at around 850 rpm and maybe 500-550 in drive. Only things I'm still noticing is little surging of rpm's at times at idle. Not all the time but some times it jumps repetitively about 100 rpm which is annoying. Still some pulsing of inside and outside lights but does seem improved after the new alternator and regulator. I don't think the issue is completely solved but I think the tune up made a noticeable improvement. I think the brake booster needs to be replaced still b/c it does hiss when pedal is pressed. As you guys have mentioned I suspect there still could be a carb issue or vacuum problem that I hope to figure out. I also do want to still check the battery when my charger arrives and the voltage when the multimeter arrives. That being said the only thing truly eating me at the moment is the intermittent surging. Will report back after I give it a decent test drive.
Some factory brake booster hiss when the brake pedal is depressed the 89 has done this since we bought it new in 89 as did the 87 and the 85 and the 84. I would consider this normal.
You should try setting/adjusting the idle mix now that things are fixed up that will help with the at idle flutter. And remember this is a carb it will never idle as smooth and consistently as fuel injection
Just finished about a 10 mile trip. Stopped once to run an errand. No stalling and no issue on restart. Only thing again is that surging was was more pronounced. Jumping 200-300 rpm at stop and seemed worse with the more brake applied and slower the speed. Disappeared as I hit the gas an increase speed. But the surging when coasting at idle had the truck jumping a little. Interested to hear thoughts.
Just finished about a 10 mile trip. Stopped once to run an errand. No stalling and no issue on restart. Only thing again is that surging was was more pronounced. Jumping 200-300 rpm at stop and seemed worse with the more brake applied and slower the speed. Disappeared as I hit the gas an increase speed. But the surging when coasting at idle had the truck jumping a little. Interested to hear thoughts.
That sounds like a vacuum leak. Time to diagnose for that. Disconnect the vacuum accessories once at time and cap to see if it goes away. If you get them all capped off and still have it it is either carburation or you have a mechanical vacuum leak. Such as EGR intake carb mounting gaskets..
So watch some vids and sprayed all around the carb. I THOUGHT I hear a change in idle when I sprayed this area....
The hose that goes to the brake booster was actually on there pretty good but the hose that goes to cruise control literally slid off with no effort. The pcv tube came off easier than I would expect. I could easily imagine that the CC hose could shake loose and or move around causing a leak. Seems to happen more when the engine is hot. The surging is very intermittent so it was hard to say if it made a difference when I played with it. Nothing holding any of those hoses on... replace? Fasten? Last observation is the surging seems to happen when engine gets hot.
Read about the egr awhile back. Mine looks to be sealed off. Much if not all emissions stuff was removed by one of the previous owners.
Also, just looking around after my drive and looks like master cylinder is leaking.
For now i cut off the ends of those hoses that were stretched out and put them back on snug. Drove it today and didn't seem much different. MAYBE a slight improvement but still some surging once the engine gets hot.
So watch some vids and sprayed all around the carb. I THOUGHT I hear a change in idle when I sprayed this area....
That appears to be the "Christmas Tree" fitting on the back of intake manifold. This is the point that supplies vacuum to the various circuits.
What are you using for spray? You have to be careful because some new eco-friendly carb cleaners are non-flammable. You can spray all day directly into a vacuum leak and it won't make any difference. To be sure, loosen a connection to create a deliberate leak and spray the area. If you get no response, the product isn't appropriate for finding vacuum leaks. I do not care to discuss how I learned this.
Your EGR is not capped off. And now that you have the vacuum tree found. Disconnect each line cap it off on the tree then test to see if the surging goes away. Do them one at time. Since you suspect the Brake booster start there. Do not disconnect the PCV leave it in place the engine/carb is calibrated for this leak.
Picture of the carb please front right and left if you please? And one of the carbon canister. Feels like you just told me you have a vacuum leak on the emissions side.
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