If you read the summary of my newest vehicle (About the Chevy K2500), you’ll see that I ran into a smell issue. Mice and ants had made their homes in the truck during its two year sabbatical in the field. I thought the smell might go away if I removed the ants’ dirt from the door seals at the floor. That’s where it seemed like the smell was coming from. It turns out the smell was under the vinyl floor cover and it was just coming out where the ants had opened up the seals. So I eventually had to rip out the flooring:
Once the vinyl flooring was up, I saw the old girl had some rusting going on. The sound-deading material and insulation was even wet when I took it out. The truck had been stored in a dry shop for about a month and a half at this point, so this was probably never going to dry out without removing it.
13 – Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds.
14 – Coolant temperature sensor signal indicates a temperature of over 275° F for 2 seconds.
15 – Coolant temperature sensor signal indicates a temperature colder than -27° F for 30 seconds after the engine has been running for at least 30 seconds.
21 – TPS voltage was above 2.5 volts for 8 seconds when the MAP sensor signal showed manifold vacuum to be 15 pounds or more.
22 – TPS voltage was under 0.2 volts for 2 seconds when the engine was running.
23 – Inlet air temperature sensor signal showed an air temperature below -22° F after the engine has been running for 5 minutes.
24 – Vehicle Speed Sensor (VSS) Circuit .
25 – Inlet air temperature sensor signal showed an air temperature over 302° F after the engine has been running for 5 minutes.
32 – EGR open command did not change MAP sensor signal. Normal EGR flow should cause slight decrease in manifold vacuum which would change MAP sensor signal.
33 – MAP sensor signal voltage was too high (low vacuum) for 5 seconds when throttle opening was under 4%.
34 – MAP sensor signal voltage was too low (high vacuum) when engine speed was under 1200 RPM or the engine speed was over 1200 RPM with a throttle position angle above 21%.
35 – Idle Air Control (IAC) System .
42 – The EST signal did not change when the ECM applied bypass voltage to the ignition module.
43 – The ECM did not detect a knock signal during near wide open throttle operation with coolant temperature above 194° F or the knock signal was present for 5 seconds or more during normal engine operation. Electronic Spark Control (ESC) Circuit .
44 – Oxygen sensor voltage was under 0.2 volts for 50 seconds of closed loop operation. (Lean Exhaust Indicated)
45 – Oxygen sensor voltage was over 0.7 volts for 30 seconds of closed loop operation with a throttle angle between 2% and 20%.(Rich Exhaust Indicated)
51 – PROM error. (MEM-CAL)
52 – CALPAK error.Fuel CALPAK Missing .
53 – System Over Voltage .
54 – Fuel pump voltage was not present at fuel pump sense line for 2 seconds after the ECM has sent the fuel pump on command.(Low Voltage)
As I talked about in my previous post, The The New Project: 1991 C1500, I need to rebuild the engine in the truck I recently bought. It’s a 4.3 liter V6 with TBI. I’ve been interested in learning to rebuild an engine since I bought my 1990 K2500, but I did a little research first to make sure I wanted to take on the task.
Should I rebuild?
There are few options when it comes to reviving a vehicle with a worn out or destroyed engine. I considered each of them before I made my decision.
Option 1: Get a Salvage Yard Engine
A lot of people say to just buy an engine from a salvaged vehicle. This would have been pretty nice. You buy the engine from a salvage yard and just swap it in. Very little down time and it gets you on the road faster. However, two of three of my local salvage yards said the truck was “too old” and they didn’t have any engines available. The third place said they could get me one shipped in from another yard, but it would be high mileage engine and would cost at least $800. I wasn’t ready to pay that for another engine that might be just as worn out as my current one.
So unless your vehicle is a bit newer, this option doesn’t really work very well.
Option 2: Get a Crate Engine
A lot of places sell crate engines, either long blocks (engine block and heads) or short blocks (just the engine block and rotating assembly), that will fit in almost any vehicle. I searched a while for a 4.3 liter V6 and found I would essentially have to pay $1,800 and a core charge of $300 for a long block. That’s a lot of money compared to rebuilding my current engine. There were also fewer options than I expected. I think this is because the V6 in these trucks is both not as common and not as desirable as the 5.7 liter V8. Also, many people swap in a newer engine like a GM LS. However, I am not interested in the wiring work that comes with that. LS engines are also very popular and expensive right now.
Option 3: Have a Local Mechanic Rebuild the Engine
I was tempted to have a local mechanic rebuild the engine for me. I’m too excited about driving this truck and I started getting impatient. I called a mechanic nearby and they told be “we don’t tear anything down past the heads”. This wouldn’t work because my problem is likely connecting rod bearings (“below” the heads) and I want the engine completely rebuilt or new. I also got this truck as a hobby and to learn more about mechanic work, so farming out all the work defeats the purpose.
Option 4: Rebuild the Engine Myself
After doing the research, I decided I want to rebuild this engine myself. It’s going to be a lot of work, but it’s my cheapest option and allows me to learn even more about engine maintenance and repair. I’m estimating it will be around $1,000 after I buy the rebuild kit and get the block honed or bored at a machine shop. But after I’m done, I will know everything there is to know about this truck and its engine. I’ll be using my Haynes Repair Manual to guide me, as usual. Wish me luck!
Wheels: Stock 1991 GM 1500 2wd wheels, 5×5 lug, 15 inch x 7 inch
Miles when purchased: ~140k (Aug 2017)
It has been just over a year since I bought the 1990 Chevrolet K2500, so obviously I needed more to work on, right? Not really, but I couldn’t pass this one up. I’ve been on the hunt for a very cheap short-wheel-base to fix up. I had a 1990 short-wheel-base Chevy C1500 in high school and it was one of those vehicles you say you should have never sold. This new one is a 1991 with a V6 and 5-speed manual transmission just like my old one. I paid $1,200 for it. Here is what it looked like the day I bought it:
It’s getting hot here in July and my 1990 Chevy truck’s AC hasn’t been converted to R134a refrigerant yet. And it’s out of refrigerant. So I’m noticing all the ways in which the interior gets heated up. The other day I was sitting in the sun waiting for someone and I realized heat was radiating off the inside of the truck’s roof. The front part was cool to the touch because it is double-layered metal, but the back part was another story. It was nearly too hot to touch and it felt like it was pumping out heat into the interior.
That’s what it looked like before I added the insulation. I used a roll of insulation I found at Home Depot. It was $10 for a 2 ft x 10 ft roll. I cut it down to 18 inches x 45 inches to fit the area I wanted to insulate. I then used 3M spray-on headliner adhesive to make it stick to the metal.
I wish I would have measured the temperature before and after. It’s a drastic improvement. I left the truck sitting in a parking lot in similar conditions for about the same amount of time as the day I noticed the heat. The interior insulation was barely warm to the touch when I came back out.
The stock headliner would have accomplished this insulation, but it’s made of pressed cardboard-like material and had fallen apart over the years. I plan on adding an aftermarket headliner from LMC at some point, but this insulation will just add to the affectiveness of the headliner when I get it.
I finally got some “new” seats. These came out of a salvaged 1994 Chevy truck, but they were originally from a 1990 model. Either year would have fit. It took me about 6 months of watching and waiting to find some decent condition, blue seats for the truck.
Before installing the seats, I thoroughly cleaned them with Shout Auto Dirt and Stain Remover (you can get it on Amazon here). They came out very clean and smelling fresh.
I finally took the plunge and got the exhaust replaced on my 1990 Chevy truck. I went with a simple one-in, one-out magnaflow muffler with a turned down outlet pipe. It sounds great, but the star of the show is the custom Y-pipe I asked my exhaust guy to make. It looks like the one pictured above. I’ll take a picture of the actual exhaust when my garage drops below 98 degrees F.
After reading in numerous places that the stock Y pipe on these trucks is very restrictive, I wanted to see if I could squeeze some performance and efficiency out of getting mine replaced. My exhaust also had holes from rusting throughout it, so it was time. Reading on tbichips.com, you’ll find this:
GM intentionally made that Y pipe restrictive to increase back pressure and most have paid someone to spread a myth that back pressure in the exhaust is GOOD. Its NOT. Air velocity is good not back pressure. The reason for the back pressure was so that the EGR smog system would work better and the increased pressure would build up a lot of heat to keep the o2 sensor hot. A good free flowing exhaust does typically need a 3 wire heated o2 sensor conversion to maintain its temperature. To fix 90% of the exhaust issues, I recommend a Flowmaster Y250300 collector from your favorite vendor and replace that section of Y pipe where the 2 pipes merge. Dramatic improvement over that stock GM design.
Here’s what the stock Y-pipe looks like:
I showed the exhaust guy a picture of that Flowmaster collector/Y-pipe and he said “I can make a pipe like that, just not as pretty”. So I said go for it. And boy is it awesome. The truck feels like it has more torque off the line, seems to have more power on the highway, and my gas mileage increased 17.5% (13.1 mpg to 15.4 mpg).
The whole system rang in at $196. Not cheap, but it was needed and I’ll recoup some of that (or all of it, eventually) with better gas mileage. Thanks to David Jones at Extreme Muffler for building and installing the new exhaust.
I just installed the TBI Air Flow Enhancer from Jegs. I had read mixed reports of the effect these bowls have on performance. Some say it doesn’t do anything and some say you can definitely feel an increase in power.
The tipping point for me to buy one was an old hotrod.com: 1993 GMC 350 Pickup – Project Jake, Part III. This is about the only “proof” I could find that the bowl makes a difference. These guys actually have a before and after dyno run for the Salad Bowl mod:
They show that the bowl gave an increase of 8 HP and 8 LB-FT of torque at the rear wheels. However, I’ve watched enough dyno runs (thanks Roadkill and Might Car Mods!) to know that pulls can vary quite a bit without anything changing on the vehicle. But I wanted one anyway, just to see.
At first I thought my air cleaner stud would be too short. I had read somewhere that you might need a longer one. Then I realized you can just back it out a bit. It will still have plenty of threads left in the throttle body, but you’ll still be able to attach your lid, as well.
And there it is, with everything buttoned back up:
So now for the big reveal: my very own opinion on the effect of the Salad Bowl mod with the TBI Air Flow Enhancer/TBI Power Charger. I definitely feel more power. Everything from taking off from a dead stop to accelerating on the highway seems to take less throttle. The truck feels like it has more “grunt”. So if you’re on the fence about getting a bowl, I’d say go for it. Or make your own.
Hopefully less throttle means more miles per gallon. I track the gas mileage of the truck here: Chevy K2500 Fuel Economy Log. I happened to fill up the tank the day before I installed the bowl, so this tank will be 95% with the bowl. We’ll see what it does to the gas mileage.
Update 05/09/2017: Did the first fill-up after the salad bowl install. It was 14.4 mpg, which is about 1.3 higher than my average before of 13.09 mpg. I also got a free-flowing exhaust installed that raised the next tank to 15.4. I wrote a bit about the exhaust here: New Exhaust on the 1990 Chevy Truck.
Update 04/28/2020: I also put an Air Flow Enhancer on the 1992 Chevrolet C1500. Once again, I feel a noticeable difference in acceleration. It feels more “torquey”. I also plan on putting on on the 1990 GMC K1500.
I had washed this bumper with soap and water multiple times over the last few months and that texture had never come off. I thought I was stuck with it or would have to get a new bumper. I tried Turtle Wax Polishing Compound and it completely removed the texture. I just used a paper shop towel and polished it by hand for a few seconds. Time to go over the rest of both bumpers now.