What's up all? Just joined. Already got a bunch of info from here to hopefully put to good use. Anyway, on to my problem(s).

First off, the vehicle is actually a 1998 Bravada. I know, you say Blazer, I say Bravada. Same animal, for the most part. I'm going to be buying it from my brother-in-law for my wife for $700. He bought it and drove it home (about a 50 mile one-way trip) and said it drove fine. Went to start it a day or two later, and it wouldn't. He immediately reasoned that it needs a fuel pump and decided to sell it to me. The only background info I have is that the engine was replaced because the previous owner was told the original had a bad head gasket, and shortly after it was replaced, the vehicle was stolen then recovered later. I'm fairly certain the engine came from a 97 or older vehicle, because there's an unused coolant temp sensor in the thermostat housing, and another one in the driver side head that's actually plugged in. I don't recall the exact mileage, but it's over 140,000. On to the good (bad) stuff.

It cold starts a little hard (2-3 tries) and idles a little lopey. Not really rough like a dead cylinder or two, but definitely not smooth like it should. Driving it down the road, it seems to accelerate smoother than it idles, but you can feel the power come and go. It bogs down and loses speed, then you feel it pick back up. Not as bad as if you were letting completely off the throttle then opening it again, but it's evident. It does it worse at steady speeds, accelerating is smoother. The first thing I noticed is the tabs on the air intake elbow that hold it onto the front of the TB are broken, so only the nut on the back side holds it on, basically causing a major air leak between the TB and the MAF. I thought that could be at least part of the cause, but holding the elbow down tight with my hand had very little effect. Regardless, that needs fixed. I have not checked the fuel pressure, I only had enough time to check for codes. The only two present are P1345 and P0740. I'm not sure if the P1345 is from the engine replacement and was fixed but never cleared, or if it's current. I would have cleared them and drove it again to see what codes reset, but alas, I think I might have run it out of gas. A couple of days before I checked the codes, I took it for a test drive. The gas gauge read 1/4 tank, but after idling roughly 15 minutes (literally, haha!), then driving it for about 5, it stalled at a stop sign. I looked at the gas gauge, and it was on the "E". It restarted after sitting a few minutes, harder than when it was cold, and ran even worse. Keeping it running long enough to get back to the house was a chore. So either the gas gauge is incorrect and it just runs worse all warmed up, or the gauge is correct and it runs bad enough that it will eat a 1/4 tank in 20 minutes.

Now for part two! I noticed the ABS light was on, so I grabbed those codes while I was at it. Ready? Here they are:
C0221
C0222
C0223
C0225
C0226
C0227
C0236
C0265
C0281

See the crap I get myself into? I did notice some growling in the front while driving it, so the wheel speed sensor codes may be from bad hubs, but I'm thinking that all or most of these codes are likely due to a failed EBCM. But, could it also be a bad ignition switch? The SES and ABS lights are the only ones on, I didn't see any light for the AWD. According to my brother-in-law, it seemed to him like the AWD was working when he drove it. That's the main reason I'm worrying about the ABS codes, since some vehicles won't allow stuff like cruise control, traction control, or 4wd/Awd to work if there's an ABS malfunction. Oh, one other thing I noticed. The door sticker says it's supposed to have P235/70R15s on it, but the tires are all P235/60R15s. I'm wondering if that could also be contributing to the codes. I know improper tire size throws off the speedometer and shift points, and will probably affect ABS performance, but I don't think it would cause malfunctions. My wife's only concern is that it runs and drives well, but the fact that it has AWD was a big plus for her, so if ABS problems causes it to not work, she'll put it on my to-do list, so might as well put it on myself now.

So there's not really a specific question to all of this. I guess I'm really looking for some enlightened input and guidance. I like to do my homework and apply it towards diagnosing, instead of diving in wallet-first and throwing parts at something until it works. I'm sure I could spend $700 on something else, and I know it obviously has some mechanical issues. But it's rust free (even with all the cladding all over it, the only spot was on the bottom edge of the lift gate), and needs a few interior pieces (it was stolen for the stereo system it had), and the wife likes it. Which is odd because she hates Buicks and Oldsmobiles because "only old f****rs drive those".

 

I'm sure you know that you need to clear all the codes and report which ones return.

a returning P1345 indicates distributor is in more than 1 tooth off and although timing is not affected it probably is cross-firing inside of the cap to wrong terminals as a result (may explain the performance problem). This one would be an easy fix and I would also replace cap/rotor if has been running that way.

A returning PO740 is a TCC circuit malfunction.

and so forth.

Better ID what engine you are working with. Front right of block on pad in front of cylinder head. Could be some big compatibility issues if it was put in as an assembly and not everything hooked up!

Vehicle doesn't care what size tires are, as long as they are the same.

 

Yeah, once I get some gas in it, that was my next step. Clear the codes and drive it again. Or at least try to, lol. A full tune up was on my to-do list whether it needs one or not. I've seen a few of theses 4.3s burn a hole thru the middle of the rotor.

 

AC Delco plugs, cap, rotor, & wires will do wonders for it. Don't waste your time or money on aftermarket stuff.

 

My old 90 C1500's 5.7L tbi runs fine with NGK plugs and the cheap OReilly cap, rotor, and wires. But those old TBIs run with just about anything. Anyway, the Bravada is going to be the wife's new vehicle, so it's not getting a lot of cheap stuff. If I put cheap stuff on it and they go bad too soon, I'll be in hot water, lol. I already have a list of maintenance stuff that, even with my employee discount, is gonna run me 400 bucks.

 

That's the truth right there.

 

Your C1500 5.7L is not a Vortec So unless you want problems with the Bravada, use AC Delco plugs, cap & rotor. AC Delco wires are OK, but Autolite Professional series wires have better specs, and they are waaaay cheaper. When it comes to a fuel pump, don't even THINK about using other than AC Delco or Delphi.

 

Yeah, that's why I said those old TBI's will run with just about any parts. They're too dumb to know any better, lol. I'd have to go down the street to my employer's competition to get Autolite wires. My $400 shopping list is just a rough idea at this point. Shocks, front hubs, ball joints, full tune up, distributor, etc. Oh, and a hood release cable. It's got a piece of coat hanger sticking out between the hood and grill. 2nd vehicle I've bought with that setup. They aren't that expensive, and they can't really be THAT hard to change.

 

Holy major double posting thread bumpage, Batman!

Update time. I bought the Bravada and dragged it home on a car dolly. My poor old C1500 really labored with it, which I found odd, since I dollied a 68 Chevelle on the same dolly with the same truck a year ago and it had no trouble. Both the Chevelle and the Bravada were dollied with the driveshaft disconnected from the axle and tied up out of the way. Might have to check the Bravada's back brakes.

Anyway, the fuel pressure checked out fine. 63 psi KOEO, and 53 psi idling. Also, it took 2 minutes to drop to 40 psi after I shut the engine off. I cleared the codes and restarted it, and P1345 returned, so I pulled the distributor and repositioned it. Cleared the codes and restarted it again, no more P1345, and it ran significantly better.
I then replaced the plugs, wires, cap, and rotor. That's when the fun started. I realized the steering shaft was in the way of pulling the #3 plug, so I unbolted the shaft at the box and tied it up out of the way. Somebody must have broken the new plug that was to go in cylinder #5, because it was an old crusty Delco but the rest were newer Champions (who the h3ll uses those these days?). Then, when pulling the passenger side plugs, I discovered that the #4 plug was a washer-seat style (rc14yc, to be exact). I couldn't get the new (proper tapered-seat) plug to thread in, it kept wanting to cross thread. So I had to put the stupid washer-seat Champion back in for now (goes right in perfectly) until I can scrounge up a thread chaser. Although I have a feeling I'll probably have to put a threaded insert in there to fix it. It runs significantly better, but still has a very slightly rough idle. It will stumble and pop if I rev it full-throttle. But it still has that worn out (and improper) Champion plug in #4, I still need to replace the broken intake elbow, and the gas is obviously bad (smells like paint thinner).

I also cleared the ABS codes, and the only one to return was I think C0220, can't remember now. I neglected to write it down, and the code reader I'm using is a cheapo I borrowed from work that doesn't have internal memory for previously scanned vehicles and codes it read from them. We just got much nicer one that does, but I knew my boss wouldn't let me borrow that one.

For some reason, I'm thinking that P0740 reset, but I haven't driven it. It hasn't moved from the spot I put it in. So I might be wrong on that. But if I'm right, and it did reset, how could it set that code without even being taken out of park?

 

That elbow needs to seal correctly. "Pirate air"= Air that's coming into the engine without being measured by the MAF. The PCM cannot maintain correct fuel trim. It causes hard starts and poor performance/mileage.