1993 Chevy Silverado Bogging severely

Tiny
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Haven't tested for vacuum yet. Was pretty busy and will be today also. I did notice how different the truck runs when it was like 40 outside vs today when it was just 5 for the high. Almost immediate bog and definitely terrible shake to it. Didn't do it too bad on the way to work considering it was in a warm garage overnight. Figured id give you an update haha.
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Tuesday, January 26th, 2010 AT 3:40 PM
Tiny
JACOBANDNICKOLAS
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HAs anyone contacted you?
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Wednesday, January 27th, 2010 AT 11:18 PM
Tiny
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I was able to borrow a vacuum gauge but only used it when it was parked. Checked out fine. But never tried it while driving. Need a longer hose for that.
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Wednesday, January 27th, 2010 AT 11:53 PM
Tiny
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I gotta figure out how to test half of these things. Maybe I have a short somewhere and frying stuff up. It was kind of backfiring today when I was giving it gas. I know it was getting enough air. Considering the aircleaner was off
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Wednesday, January 27th, 2010 AT 11:58 PM
Tiny
MERLIN2021
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What is the fuel pressure? At least 50psi is what we want. Also unplug EGR and test drive it.
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Thursday, January 28th, 2010 AT 3:31 PM
Tiny
MERLIN2021
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Didnt see IAC on the list, test it this way: Idle Air Control (IAC) Motor 1. Disconnect harness connector to motor. Check resistance across IAC coil terminals "A" to "B" and "C" to "D". See Fig. 5 . Resistance should be 40-80 ohms. If okay, go to next step. If resistance is not as specified, replace IAC motor. 2. Check resistance between IAC terminals "B" to "C" and "A" to "D". Resistance should be infinite. If resistance is not as specified, replace IAC motor. NOTE: Functional testing of Idle Air Control (IAC) motor requires a scan tester capable of cycling ECM output devices (bidirectional) or a special IAC Driver and Node Light Set (222L or J-37027). Flow charts in TESTS W/CODES articles in this section may refer to Tech 1 tester, General Motors' bidirectional tester. Page 1 of 1 1/28/2010 ...


https://www.2carpros.com/forum/automotive_pictures/62217_iac_3.jpg

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Thursday, January 28th, 2010 AT 3:54 PM
Tiny
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So. I did a compression type check. I wanted to check that timing chain again. So I took a socket with a long bar and spun the alternator so it would spin everything else. I noticed when I spun it slow for a good bit the router on the distributor didnt move. It eventually started to move. Isn't that supposed to move instantly when I turn the engine? If so. Im assuming the timing chain is lose.

If that's the case. I'm going to spend the weekend on ripping all of that apart and putting a new one in. And probably even fix my oil leak and for the hell of it put a new water pump in, haha.
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Monday, February 8th, 2010 AT 2:45 AM
Tiny
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First, dodnt spin the motor via the alternator pulley, get down on the crankshaft. Belts can slip. Turning the crank insures that the timing chain will turn the cam. If the distributor doesnt move then, you either have slack in the chain, or a bad gear on the distributor/cam.
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Tuesday, February 9th, 2010 AT 2:04 AM
Tiny
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Oh I made sure th engine was turning. I had my buddy tell me when the engine fan was turning while I watched the distributor. They were way off. Well I dont think the distributor would be bad since it's brand new. I don't know about the camshaft though. Im hoping it's the chain.
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Tuesday, February 9th, 2010 AT 9:35 AM
Tiny
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Put the crank at TDC and see if the #1 piston is also at TDC, and rotor in the distributor is ready to fire plug#1.
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Wednesday, February 10th, 2010 AT 12:58 PM
Tiny
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Yep made sure that I did that before putting the distributor. I found a piece of lath and marked on the firewall where the rotor was at. Would it even run if they were all off? Dont think it would start.

But yeah startin tomorrow I'm going to get a new timing chain and rip apart everything. So hopefully I can come back with good news at the end of all this haha.
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Thursday, February 11th, 2010 AT 11:40 PM
Tiny
MERLIN2021
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Ok, you have a manual for help? Timing marks?
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Friday, February 12th, 2010 AT 3:00 PM
Tiny
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Ok well here's the update. I just finished installing the new timing chain. Also fixed my major oil leak which was in the cap that covers the timing chain and while I was at it changed the water pump. Put it all together. Unplugged the wire to start timing the engine. Was a little off so got it where it should be. Turned off the engine and plugged the wire in, everything WORKED.

Took a test drive to the grocery store. Left it in third gear to see if I could hit 70. Bogged like hell. VERYYY DISAPPOINTED. Haha. That was a lot of work. It runs a bit smoother now with the newer parts but blah. Only thing I haven't touched yet is the fuel pump. Other than that. I think I have changed every single thing in this truck besides the engine and other things that dont deal with air/fuel system. Blah.
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Monday, February 15th, 2010 AT 4:26 PM
Tiny
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It also did the usual jump when it was slowing down. Was jerkin around quite a bit.
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Monday, February 15th, 2010 AT 4:51 PM
Tiny
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Sounds like the distributor itself, check for sideplay on the shaft. If you have a dwell meter see if the dwell changes more than 3 degress when engine revs to 2500-3000 RPM, if it does, replace distrib. Any backfire thru the intake?
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Monday, February 15th, 2010 AT 7:00 PM
Tiny
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Not sure. I never heard backfire from the exhaust but feels like a pop or whatever from the front end. I dunno how it could be distributor when that's brand new haha. I replaced that whole thing.
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Monday, February 15th, 2010 AT 7:24 PM
Tiny
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Do you think if I hooked up the vacuum gauge it would show a backfire in it?
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Monday, February 15th, 2010 AT 7:26 PM
Tiny
MERLIN2021
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I mean backfire or poping in the throtlle body area up front, or from the muffler. I will send a PDF on vacuum gauge testing, it can help find any worn engine parts.
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Tuesday, February 16th, 2010 AT 3:56 PM
Tiny
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Yes it does that. Only when I'm driving with the gas down. Seems when I hit a higher rpm is when it will do it the most. Noticed I was almost able to recreate the popping when Im in 3rd gear trying to go between 60 - 70 mph. Then it bogs bad, slows down. When I give it more gas it pops in the throttle body.
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Tuesday, February 16th, 2010 AT 4:50 PM
Tiny
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I read up on some stuff from 2carpro's site, one of the tutorials on backfiring. One thing I haven't cahnged yet that they mention coudld cause the intake backfires is the fuel pump which is the only thing I haven't changed yet. Other than that, I have literally changed everything that deals with air/fuel.
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Tuesday, February 16th, 2010 AT 4:52 PM

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