Everything posted by ifixedit
The need to shut off your truck is an indicator of a situation that will only get worse. In your case if you've never replaced the throttle body then it's probably due. In the case of a new throttle body and it's still doing it could be several things, throttle body aside. Key thing, don't start throwing parts at it and the codes you get may not necessarily point to the right thing! Other areas of issue are the accelerator pedal assembly. In my case I found that in 2003 Chevy must have made some mid year change on the gauge of wires leading from the pedal assembly through the firewall. I determined that my original pedal assembly was junk and had a short in the plug at the pedal, wiggling it around with the truck running would produce the reduced power message, and even after replacing the switch in it 2x, still no luck. I pulled a complete accelerator pedal assembly WITH the harness (important) out of a junk 2003 at the local wrecking yard, takes a whole 5 minutes to extract it. Do not disconnect the harness, leave it intact if you can as this seems the more you disconnect and reconnect things it only disturb things further! The plugs are very sensitive. I found that the accelerator pedal assembly I pulled from the junkyard had a heavier gauge of wire than my original and looked to be a bit better made overall, so somewhere along the line GM figured something needed to be looked at. I installed the pedal with harness that goes through the firewall and connects to the TAC (throttle actuator control) and this worked well until my cheap China made TB gave up the ghost again. One of the codes you may get points to the TAC as being faulty. This is the black box mounted on the firewall that the accelerator pedal harness plugs in to. I will guarantee you if you get a code that the TAC is bad, it is not. Don't waste your money buying a new one, it isn't the problem. I found out the hard way on this one. So, other than what else I list below, the 2 main things to look at replacing is the TB itself, and possibly a good used accelerator pedal assembly with harness from the junkyard. Other areas to look at: The ground wires on the frame under the drivers side door, things here in MN cause it to get pretty crusty there. The ground wire on the back of the drivers side cylinder head (royal pain in the rear to get at). The plug that connects to the TB, make sure it is clean and dry and that none of the contacts in the plug have issues. If it looks like the plug is questionable and some of the pins are not making good contact, they sell a pigtail harness at the auto parts stores. As for the new TB, is it a good quality one? I found the made in China specials lasted anywhere from a max of 3 months to as little as 2 weeks. They're all JUNK, don't buy a made in China TB. Marc
No problem, hope what I've provided helps. I did a little research and was actually a bit wrong about the last throttle body I bought at Advanced Auto Parts. It's a Techsmart and is actually made in Mexico, not the US. They also had an option at the time for yet another made in China unit but after all the bad luck I had with them, even though they were considerably less $$ up front, I spent the $200 + on the Techsmart and it's paid for itself so far, zero problems with it. I also recall they had a good warranty on them if it were to fail. They also now have an AC Delco reman but I tried one of them as well and it lasted like 6 months and I was under the hood again. As for fixing the one you have, they do have a repair kit available as well but it will take more than 15 minutes to do the job. The throttle body will need to come off, then you have to drill out the rivets that hold the black cover in place, then hope to repair it without messing anything up, put it back together and get everything right. I pondered that option and decided against it. Marc
Also as an add on here. Disconnect the battery when replacing the throttle body and touch the battery leads together, this and the time taken to replace the throttle body gives the computer time to clear any codes stored, and you basically start from square one on re-connect and first start. There are several procedures outlined online as to doing the throttle body relearn procedure, but I found the best way to do it is just start the engine and let it idle (don't touch the throttle) until it comes up to full temp 210 degrees. Once you're at 210 put your foot on the brake, let it idle and put it in gear for a few, but don't let the truck move. Put it back in park, still letting it idle and turn on the AC for a few, then put it in gear with the AC on and again keep your foot on the brake and just let it idle for a few. After this take it for a normal drive and vary the throttle but don't go nuts at first and go drag racing. At first the truck will be pretty poochy and will seem to not have a lot of power. What's going on is it's re-learning as you drive and you will have to drive it for a few days as it re-maps everything. After I drove mine a few days I began stabbing the pedal to the floor at various speeds and the truck began to come back to life in fairly short order. It takes a number of these flooring procedures but again, all was back to normal in a fairly short period. If you want to try the throttle body repair kit vs. replacing the throttle body it's up to you, but again my 2 cents worth is I wouldn't especially if the repair kit is not US made. Marc
Hi all, I haven't been on this forum for a long time but got an email notice this morning that this old thread has suddenly come back to life. A couple of things I've learned since originally posting this that may also help. In addition to all I've listed to go through and check, the grounds being one of the more important to check, in particular the ground on the frame under the drivers door and the one on the back of the drivers side cylinder head (very hard to see and you have to feel around to find it), the other issue is the throttle body itself. Here's what I've learned that is also at issue..... There is what they refer to as a wiper inside the the throttle body under the black cover where the plug connects and basically the guts of the throttle body with the gears and so on reside. Basically there's a small plate inside with electrical contacts on it that wear out over time, causing the signal to jump erratically from the contacts hence throwing the truck into reduced power mode because the computer is getting errant readings as to the position of the throttle body. Auto parts stores such as Advanced do now sell a repair kit for the throttle body and I've seen a few videos online outlining the fix but my 2 cents worth is I wouldn't touch it with a 10 foot pole. The answer if you've exhausted all other possibilities and it is still happening is to replace the throttle body with a new 'quality' unit. Beware of the cheap made over seas by the CH-ina company units, don't waste your money as they will last around 6 months to a year without issue and will be at it again, trust me I learned the hard way! The last throttle body I put on my 03 was made in the USA, was about two years ago now and have not had one problem since. At the time the factory replacement was an AC Delco but they were on back order and were impossible to find. If you have a throttle body with a lot of rounds on it (i.e. lots of miles), find a good quality built in the US unit and your problem should be solved. I don't remember the brand I ended up buying but it was US made and I got it at Advanced Auto Parts, they should still have them. Hope this helps, Marc
Hi all, I saw an old post here from 2014 I replied to on this subject, but thought since it is now 2019 and maybe there's been a few changes that I'd start a new thread and see if anyone here has the answer to this. The wife and I just picked up new trucks on lease, mine a 19 Silverado LD and her's a 19 Colorado. I'd like to be able to activate the backup camera while towing just to be sure things with the trailer, hitch, straps, (nothing is ready to fall off! ) ect., are OK as I drive. On the Colorado there's a camera icon on the display you can tap while driving and you can then see behind you same as when you're backing up. The dealer claims I can do the same with my LD, however there is no camera icon on the display like there is on the Colorado, and so far haven't been able to figure out if I can even make the camera work while driving or not. I did read on the internet that there's possibly a setting to activate the camera while in forward gears in the 'driver assist' settings. Haven't tried it yet but if anyone here can confirm one way or the other would be greatly appreciated.
The wife and I just picked up new trucks, mine a 19 LD and hers a 19 Colorado. On the Colorado you can activate the camera while driving. There's an icon on the display, just tap it and viola, you can see behind while you're driving. The dealer told me on my LD that I could do the same thing but there's no camera icon on the display like there is on the Colorado, and so far haven't been able to figure out how to make it work. You'd think if the Colorado does it then the Silverado would as well? I too would like to view behind while towing as an example and you'd think this would be a standard thing. I read online that there may be a setting in the 'driver assist' settings to use the backup camera while driving forward. I'll do some additional investigating and see what I come up with.
ifixedit replied to Mpalmer's topic in 1973-1987 Chevrolet & GMC Square Body / Rounded Line PickupsYou should be able to drop a 350 in it without problem and as far as motor mounts go, everything should bolt right up. Places like Summit and Jegs sell complete 350's ready to run quite reasonably priced, or as long blocks and all you generally need to supply are things like the intake, valve covers, distributor, carb and so on. If it were me, I'd look for a 1996-2000 long block with the vortec heads (no, 305's of any year do not have vortec heads), but you would need to verify that the long block you buy has provisions for a mechanical fuel pump. Why a 350 with vortec heads? Arguably the vortec heads are the best out of the box iron heads GM ever produced, including those from the hot rod days of the 1960's and up to 1970. Their only limitation without machine work is camshaft lift which is limited to about .450 lift, some say you can go a bit more, but for a truck you're looking for torque, not high RPM, so a high lift cam is not needed anyways and there are several aftermarket cams that will stay under the lift limitation and give you tons of low end torque and you'd make 300 HP pretty easy. The other plus is if you go with the 1996-2000 engine you get the roller cam block, so no worries about breaking in a flat tappet cam shaft. Summit and Jegs have cams they can recommend and would work nice. I'd go with a dual plane intake designed for idle to 5500 RPM operation (the intake will have to be for vortec heads), a 600 CFM carb such as an Edelbrock performer and you could throw a set of headers on it (also from Summit or Jegs), a free flowing dual exhaust and you'd have a nice combo that would be fun to drive. You'll be fine with the transmission you have and you really wouldn't want to throw much more power at it than the recipe I outline here. One thing not mentioned in your question: Is your truck computer controlled or is that part long gone?
Most 'from the factory' small block Chevy's will indicate a red-line around 4500 RPM on the factory tachometer. You can run them safely up to around 5500 RPM, but why beat on it? You wouldn't be gaining anything anyways as the stock camshaft specs will not be targeted for this high an RPM. I also like to play it on the safe side with stock bottom end components and stay under 5000.
If you messed up the plug wires you'd think you'd at least get a pop or a backfire when cranking. Did you check for spark at the plugs? If your truck has the same rinky dink distributor cap as my 98 Yukon they're kind of a joke and after sitting, especially when the cap gets older and if it's been wet or damp they can be stubborn to start. I think what happens when the cap gets bad is yes you do get spark, but it's erratic and is jumping all over under the cap and not going to the wire it should be going to, hence it won't start. I've had a similar issue in the past and again recently with my Yukon, l put a new cap and rotor on it and the thing fired right up, no issues since. Does your cap look like this? >>>https://www.1aauto.com/distributor-cap-and-rotor-kit/i/1aedk00042?f=699211&y=1998&utm_campaign=gb_csv_br&utm_content=EDK&gclid=Cj0KCQjwierMBRCHARIsAHl9i4HNUcqa2OfCGdwyppmvDtnQAvj4EQnDqNMpyKEVpyvri-AH-ZnFYRwaAjd_EALw_wcB
Plug for the water temp sensor on the drivers side cylinder head? If it's that short it probably wouldn't be long enough to reach anything on the intake manifold, and if it was anything unplugged there I'm sure the check engine light would be on. Could also be the plug to the original horn?
Ahhh, blown head gasket. That could definitely cause that type of noise. Had a slightly leaking head gasket on my 350 in my Camaro last summer after a rebuild, it was kind of a chirping metallic squeaking sound off and on and I could not for the life of me figure out what the issue was. Once I had the head (Dart, junk!) off you could see a dark spot on the block deck surface where the exhaust gases had been escaping under the gasket. Fortunately for me there was no coolant leak. I turned the Darts in and got a refund, put on a set of GM Vortecs and VIOLA! Runs like a champ!
A bad flex plate can be tough to determine without removing it as they crack very close to the bolt holes which is tough to see when the converter is in the way. It's possibly the flex plate but I'd more so suspect the torque converter itself. A bad converter will usually make a clunking or ticking sound when they are getting bad, it may also make a creeking or kind of a metal on metal scraping sound when you go from drive to reverse with your foot on the brake. Can you remove the tranny dust / inspection cover and let it idle in park while you take a look at the converter spinning from under the truck? If it's the converter it will be pretty obvious, you'll be able to hear it. A bad or vibrating converter could also cause the engine to feel like the idle is rough.
The 6.0 in my 03 has always been a bit clickity clacky as well, and I also suspect it's the injectors making the noise. As others have said here, these engines are a bit noisy. I'll also agree with the others here, I don't think it's lifters or you'd really hear it, especially on cold start up. If it is lifters another trick is dump in a quart or two of kerosene before you change the oil, let it idle for a few minutes and then change the oil, the kerosene serves the same purpose, flushes the engine. Did that on my 98 Yukon that had pretty bad lifter click on cold start up, cured it 100%.
O.K., I'll try clear up a bit of confusion here. The tires you have on your truck right now have a 110 rating which means they are good for 2337 lbs. per tire and should be at the max 44 psi. if you are coming in close to the 2337 lbs. per tire rating. 2337 x 4 = 9348 lbs. total that the 4 tires are rated to safely carry @ 44 psi. In order to figure out how much additional room you have to play with in terms of what extra lbs. you can load them down with you will need to know the weight of the vehicle including passengers, cargo and all fluids topped off first. This tire size is a low profile more of a 'touring / high performance' tire (not a heavy haul truck tire), again typically seen on SUV's meant to carry the vehicle, passengers and 'normal' cargo + maybe a small trailer or boat, not much more. Googling your Escalade I see weights coming in from 5700 to around 6000 lbs. but it doesn't state whether or not that's with fluids. Then you have to add in passengers and cargo, etc. I'd estimate by the time all is factored in you could easily be adding another give or take 1500 lbs., so now you're tipping the scales somewhere in the 7500 lbs. range. This means you've got a cushion of somewhere around 2000 lbs. additional weight to play with. Next question is, how much tongue weight on this trailer of yours? I don't know, just me, but overall it sounds like your getting up pretty darn close to the limit on the tires and asking them to perhaps do a bit more than they are meant to. The highest rated tire in this size is going to have a 114 rating which bumps you up to 2601 lbs. per tire at max inflation of 50 psi which is 264 lbs. per tire more carrying capacity than the tires you have on it now. For 4 tires total with the 114 rating that's good for 10,404 lbs @ 50 psi. Bridgestone, Yok and Toyo, among others offer a 114 rated tire in the 285/45R22 size. I can say this for sure, if you stick with the tires you have and you're going to do what you plan with this trip, at a minimum I would CERTAINLY bump them up to the 44 psi. and no less, AND watch your top speeds. Forget the chalk ideas and other tricks to read tires. A good / accurate tire pressure gauge, a tread depth gauge, and a good eye are all you need.
I sell commercial truck tires for a living. The only way to be sure is check the sidewall of the tires. Each tire size (and it's given load range rating) will be stated on the sidewall showing the max weight capacity per tire in lbs. at a given air pressure of 'X' psi. Based on the 44 psi it certainly sounds like what you have are not at least 10 ply 'LT' tires (they generally indicate around 80 psi @ max weight). For what you're towing and the long distance traveling, especially with the summer temps and high speed operation, I would surely recommend for that kind of weight in an already heavy vehicle as it is that you go with the LT tire if the tires you have on now don't show sufficient numbers for what you are doing. It's fairly typical on SUV's to not see the higher ply rated tires for ride reasons, but then you are limited to what you can tow. It is true that you should raise your air pressure to the stated 44 psi if you are maxing the tires out. The 44 psi is a cold reading when the tires are cool such as when the truck has sat overnight as an example. The tires will heat up as you drive and additional pressure will build in the tire as they reach and are running at operating temperature, the engineers factor this into the tire design. However, generally speaking, if a tire wears faster on the outer ribs vs. the center, the tire is being run (at operating temperature) under inflated, if it wears faster in the middle of the tread it is being run (at operating temperature) over inflated, but this will also depend some on the tread pattern design and some can be tricky to determine if over or under inflated. Some tread pattern designs will display both the outer ribs and center rib that is wearing faster than the second row of lugs as an example, if this is the case this is also an indication of over inflation. Bottom line, you're probably pushing the tires you have now to the limit and they are very likely not rated to 'safely' carry the weight of the vehicle, the load inside the vehicle (full tank of fuel, occupants, cargo, etc.,), plus the load of the trailer at highway speeds of 70+ MPH. Unless you can verify max load (weight per tire) capacity and it's in the safe zone with some room to spare, I wouldn't take the chance with what you have on now.
By 1978 the small block Chevy had been basically 'killed' by emissions and low compression figures and were developing the lowest figures known to man. The highest rated 350 in 1978 was putting out around a whopping 175 HP (on a good day) at best and that was likely in the Corvette, this one is probably in the 165 HP category. I can't help on the trans case but the tranny itself I would think is either a TH350 or TH400. As far as determining rear axle gear ratio, there should be a metal tag somewhere on the rear diff, you'd need the numbers off of it to determine what rear end and gears it came with which you should be able to reference online or possibly even at either an auto parts store or a GM parts counter.
Awesome find, especially with the big block! I'm jealous! I'll throw in a few things. First, unless I'm just not seeing it I don't see an intake point for the PVC. Put either a breather in the passenger side valve cover or run one of those metal lines from the valve cover to the bottom of the air filter base, without either you're putting a lot of suction on the crankcase which is not good for seals, etc. and could cause some leaks and oil consumption and also cause running issues. A good modern HEI distributor with an adjustable vacuum advance is another good add on which will help with both fuel economy and will wake it up some because of the benefits of the combined mechanical and vacuum advance which should be used on all 'street driven' vehicles of this vintage. As for the carb, unless the Q-Jet is leaking from the bottom plugs which is quite common (signs of it is hard starting or a seemingly flooded engine after it has been ran and then has sat for 20 or so minutes), the Q-Jets are very good street carburetors and all are actually rated to flow 750 cfm regardless of what people say and are actually quite simple to rebuild as well, you just need the numbers off the carb for the correct rebuild kit. If you want to go with a new carb I have pretty extensive experience with the Edelbrock performer and Thunder series (basically both are the same with exception of the adjustable air door on the secondaries of the Thunder series), and are very simple to tune and work on as well, easier than even the Q-Jet, there are available tuning kits which contain a selection of rods and jets, but I've found the Edelbrocks are quite good right out of the box. Nothing wrong with a Holley but they are a bit more work to take apart and tune and it usually involves changing both the jets and the power-valve which can be a bit of a guessing game compared to the ease I've found working on the Edelbrocks. If it's screaming at 60 MPH then I'd guess it's geared pretty low which most pickups were back in the day, so it should have a hell of a hole shot and run right up to 60 MPH in a hurry, if not I'd suspect the overall timing situation combined with a new distributor and the PVC situation I describe above would be good things to look at first. BTW: Use manifold vacuum for the vacuum advance, not timed (or what some refer to as ported). Other than that and the other suggestions made here, drive it and have fun!
First thing is pull the codes to see what it is telling you. You're likely to have 2 - 3 different codes. I don't have the code numbers in front of me at the moment but the likely codes to come up will pertain to issues with the TAC (throttle actuator control, DON'T WASTE YOUR TIME REPLACING IT!) or a correlation issue between the pedal sensor (the one on the gas pedal) and the TB (throttle body). If it is any of these codes it is likely just a simple grounding issue, the challenge is figuring out where the grounding issue is However, for more ideas and things to look at read through this entire post I did elsewhere here on the subject >>> http://www.gm-trucks.com/forums/topic/161040-dreaded-reduced-engine-power-issue/
Well, the only other guess I've got is what you saw coming out of the TB injector wasn't gas. Maybe you have some water in the tank? Again as mentioned above by muddkatt, it doesn't make any sense that it wouldn't run if it is getting both fuel and spark. Try squirting a shot of gas directly into the TB, then crank and see if it does anything. If it doesn't fire then I'd say there's some kind of intermittent disruption in the ignition.
Yep, if you've got spark and fuel it should run. Did anyone by chance either disturb the timing by moving the distributor or possibly mess with the plug wires and install them on the wrong cylinders?
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