SVPete

Been in Korea, Texas, Maryland, Kansas, and Arizona.....summers and winters.....with just the mechanical fan. No problems. That said, my truck never had A/C nor do I tow.

which oil filter? Typically it was Fram, which would come from the various oil changing outlets. Current filter is STP. I am now engaged in doing my own periodic maintenance this century and have done a lot to my truck in the last year. Finding this club really motivated me into preserving the truck.

Since I still have my original engine, I use Lucas oil stabilizer (not a promo) which keeps lubricant up on the rocker arms and the like. I had the "clatter" you are likely hearing until I started using it.

What Cruiser said ^^^^^ Experienced your issue also. In the process of cleaning ground connections, it went away. The ground terminal for my heater was also installed upside down (from the factory), which means it was barely making contact with the body.

I had a similar problem on my 1988. Would run.....stumble and die (unless I caught it by always keeping my foot over the accelerator)....injectors would fire a few more times flooding the engine...either crank forever to start or wait about 15 minutes. Replaced the coil, spark plug wires, and EGR at the same time. The EGR transducer was inop (comes with a new EGR.....the internal diaphragm spring had rusted to powder), but while waiting for that to come in, I had also ordered wires and coil (coil was the original, this was 2015)....unfortunately, I broke a plug wire while waiting for the parts, that's why I ended up replacing all items at the same time, not because I believed they, collectively, were my problem.

Got one from rockauto. No complaints.

The thread you referenced states the black line is the vacuum source for the inside controls. Refer to posts four and seven.

Stock 1988 with P235 tires. 25 mile round trip to work with an average speed of 35-40 mph. 20-21 mpg.

Any resolution?

Above the emergency brake handle.

As a quick follow up since I was at Cruisers website......check the vacuum line running from the throttle body to the MAP sensor.

It could be quite a few things. Start with Cruiser54's tips first, if you haven't already. 1,3,4, and 5 are kind of "musts" (or "haftas" to quote Cruiser) Go to Cruiser54.com. Many of his tips will help you confirm functionality of several components which can cause your problem and avoid parts swapping. Agree, fuel pressure check is needed along the way. There are many members smarter and more experienced than me, but most will direct you to Cruisers tips first also. To relate a problem I experienced for years.....Truck would die (at an inopportune location, like an intersection during rush hour), injectors would fire a few more times flooding the engine. So I had to wait it out for 10+ minutes looking like a lame gebronie who should just get a new car. Sometimes I could be driving a 45 mph and it would just die electrically, and the injectors would fire some more, flooding the engine. Popping the clutch would make the truck run all out of time it seemed like. So again, pull over and wait out the flooding. Not sure exactly what part(s) was the culprit. I know the EGR had an issue, I replaced it and the coil at the same time (it was the original from 1988, this was 2015) and presto! problem solved. Why does this matter and how does this relate to your situation? I followed many of Cruisers tips while I worked on this late last summer. What his tips did for me was save me money from just buying parts and then being aggravated when they didn't solve the problem. Start with his tips. This is not a paid testimonial.

In that area, it kind of looks like the blower motor connector on my truck, although mine doesn't have the blue cap. So I'm not sure.

By "audio alarm", did you mean "chime module"?

Not sure about the brown wire at this moment....pull the chime module (black or blue box on mounted on the left side of your fuse box) and see if that stops the fuse from blowing. Type "chime module" in the search box on the main mj tech page. Some of the results may relate to the situation you are experiencing. You can beat this.

Obviously I am partial to 1988, since it has lasted with my abuse for 28 years.....so far.

Mine has been on since the truck was new when we bought it. It shows the scars from objects it has warned me from continuing to drive over. I believe in it.

I guess I'll venture out here.... While our truck was still under warranty (that's along time ago and it was my wife's when new, the truck, not the wife), it started dying when you first started to drive in the morning. Restart, and it would run fine the rest of the day. Wow - looked in the file and I still have the paperwork from the dealer for that issue. It says: "hesitates, surges, won't go in first gear, dies in a.m." "tuned, replaced plugs, cleaned intake manifold, set base idle". (I don't remember surging or not going into first gear) Parts reflect: plugs, and TPS and O2 sensor ordered. I remember my wife told me they disconnected something so it would run while they were waiting for the parts to come in (O2 I think). The truck ran fine while whatever was disconnected and ran fine when the parts were installed. Now, for EGR....I hypothesize that the EGR could cause some issues like this also. I had hesitation issues and random stalling for a long time until around October 2015. After working through many of Cruisers tips, I firmly believed the EGR was the root of my problem. Unfortunately, while waiting for my EGR to come in (and separately I had ordered new plugs, wires, and coil {original was still installed}) I broke a plug wire.....so when the EGR came in I had to wait and replaced everything mentioned at once. Truck ran like it was supposed to for the first time in 9+ years. I took the old transducer apart (which comes with a new EGR) and discovered the diaphragm spring had rusted to nothingness, the vacuum bleed port was clogged, and the exhaust pressure port was clogged. The old EGR appears to be partially open, but I haven't really investigated that although I still have it. So, in my experiences, both the O2 sensor and EGR were connected to stalling / hesitation issues. Nobody wants to just "parts swap", but perhaps start with the cheaper of the two, probably the O2 which won't really hurt you to replace. Hope it helps.

Concur with your first sentence....recently I started buying gas from the local Shell station. Cost is the same and I went from 18-19 mpg to 21.

By the photo, that radiator looks pretty clogged. It looks like a starting point for the overheating problem. In addition to the taped hose that looks like it has been leaking also.

Check rockauto to see if the part numbers are the same.

As an update to my previous post....it looks like you are missing the bracket that holds the two pieces of the vacuum harness (mentioned by fiatslug and in the photo) securely together and in position. Without it, you run the chance of your brand-new harness(es) vibrating around the engine area and breaking. So if you buy the new harnesses, you will need to either get a bracket from the junkyard or figure something out to hold the assembly securely in place. In fiatslug's photo, the bracket I am writing about is right above the cable loop behind the power steering pump. Also, I wonder if you have a high idle with the MAP connected where it is in your drawing. Unless someone plugged the port in the throttle body where it is supposed to connect to, you have got to be sucking air there. Search on the site, other club members have used steel brake line to run from the throttle body to the MAP sensor....but that may be a future project to undertake.

I believe the 8mm stud Cruiser is referring to one of the studs holding the parking brake mechanism to the left side of the cab. It is behind/above the kick panel next to where your left foot would be when applying the parking brake. That's where I ran my extra ground to. While you were back in your tail lights, hopefully you refreshed the ground behind your drivers tail light per Cruiser's tip #1. Do your Reverse lights work? Rear license plates lights work? If they do or don't it could help with diagnosis. A test light or a multimeter will really help you to confirm power getting to places.

The line labeled "orifice" in the diagram is supposed to go where your drawing (red line) shows the MAP sensor connected to. The MAP sensor is supposed to be connected to the throttle body. Look on the base of the throttle body where the diagram shows it running to. You can make it out in fiatslug's photo of a remarkably clean engine. Buy both harnesses as fiatslug recommends. The transducer comes with a new EGR valve (75-ish bucks). I am pretty sure you can't get just the transducer.