Search the Community
Showing results for tags '454'.
Found 15 results
-
1996 GMC Sierra 7.4 C3500 strange engine problems.
sonicdude10 posted a question in Ask the GM Technician
New guy here with engine problems. All parts are stock. No modifications have been done to engine and engine management to our knowledge. With that said, here is what is going on. Truck is a 1996 GMC Sierra. Crew cab, long bed, C3500, non dually. Has 7.4 454 Vortec and 4l80e transmission. Driveline has 147,000 miles and engine has good compression. All cylinders read 120 to 140 PSI. What's going on is the engine refuses to run properly. First up is the MAF sensor. Had the engine light on the dash so I used our OBD2 scan reader on it. Got P0102 which is Mass Air Flow sensor low output. Replaced the sensor with a Bosch unit and cleared the code. Next engine start that same code came back. I checked all the wires and plugs that section of the harness goes through. It has a good run to the computer. No frays or breaks. I even reset all plugs thinking there might have been some resistance in the connectors. No dice. Code comes back every time I clear it. Any ideas? Next up is the really serious problem that prevents the engine from running properly when cold. Low fuel pressure. According to our gauge it only has 20 PSI max and leaks down as soon as the pump turns off. On the fuel system we have a new pump in tank, fresh filter, and new regulator. That was a pain to install as the top of the intake manifold had to come off. Still have the low pressure and leak down. We thought the injectors were leaky but the thing is lean at idle as we sprayed starting fluid in the intake tube and the idle evened out. When cold it doesn't want to idle at all but will even out at 650 to 750 RPM when warm. Any idea what is going on? We have no idea what type of pump is in the tank as the people who own the truck put it in before we were tasked with fixing it. Still have the stock one. We plan to pressure test it and if it can go up to at least 80 PSI we will just put it back in and see what happens. So, any ideas on what is going on? I can record videos if any of you want to see the engine and hear it running. If anyone can figure this out I would greatly appreciate it as this goes beyond my knowledge of fuel injection problems. -
driving a 97 k2500 camper special, 4l80e with 454 vortec couple days ago I got in my truck after work and noticed it would stumble when hot, 100C no problem but a little bit warmer and i would have issues. always under load during acceleration. got home and idled in drive and it felt like an obvious misfire, RPM would drop to about 500. pop it in neutral or park and no misfire or stumbling, its been confusing me since in the mornings when i pull it out the garage it has no problems all the way to work (5 minutes highway and 5 minutes city) but end of the day and evening- same issue bought the truck with 268km now has 276, oil change every 5000k. did fuel pump (48psi at idle now) FPR, distributor cap and rotor, plug wires and plugs, ran seafoam through the intake and in the fuel tank. ive heard of distributor gears going south but id assume then i would have the issue when cold too. runs like a top at any temp below 100C, no engine light, plugged the scanner in anyways and no codes whatsoever. any help is appreciated, looked through forums for a couple days now but nothing exactly like what I'm experiencing. kevin, -
I have an interesting overheating problem with my 1990 C3500 Silverado 7.4L. I recently bought the truck from an uncle who, I'm guessing, screwed me on the deal... We use the truck to tow our travel trailer (22ft. roughly 5000lb). Prior to our first voyage out, we drove the truck around town to make sure everything worked well. After a few trips to our main hike spot I noticed the truck would run warm, 220-240, for a short time and then spike down to 210. I assumed it was the thermostat sticking. So I replaced the thermostat with a 180 degree unit. I topped off the coolant in the reservoir and it seemed to have fixed the problem. We went on our first trip, now pulling the trailer, and at our halfway point, I got off the freeway to fill up the truck. about 20 seconds after we dropped our speed below 30 mph the truck spiked, redlining above 260. After starting it up, it quickly started to overheat again until we hit the freeway speeds and all was good. This behavior continued up until we hit our destination. Thankfully, my mechanic brother-in-law was camping with us. He thought it was the fan clutch but after looking at the radiator, I was about 2.5 gallons low on coolant. Since we were out camping, I used the rest of the gallon I had and filled the rest up with water. Brother-in-law said the water pump looked like it was running good and it might have just been under-filled when my uncle replaced the radiator. Ran ok until we slowed down off the freeway. It looked like the coolant would get hot and boiling out of the reservoir. I just kept topping off the radiator and driving home (picked up coolant 50/50 on the way back) Looked at it at home and noticed a leak above the drain valve. Tightened the valve about 1/4 turn, filled up the radiator and again the truck ran fine until our next trip. Same problems, had someone bring out a new radiator cap since it looked like the coolant was not being pulled back into the radiator. Coming back we had the same problem. I since replaced the hose from the radiator to the reservoir and "burped" the system by running the truck and squeezing the upper radiator hose until the coolant level would no longer drop in the radiator. The oil looks really clean (not milky or showing signs of water/bubbles). Coolant looks clean and I have topped of the radiator last with concentrate coolant to account for the water I added before. So I don't think it's the head gasket. I rotated the fan with the truck off and it stopped immediately after letting go. There wasn't any play when I tried moving the fan around so I don't think it's the fan/fan clutch. I hear an electric fan on when it's overheating/hot and the fan clutch kick in when its really hot. Rather than purchasing a bunch of new parts I thought I would get on here and ask a couple questions and see if anyone might have some things to try out. Would having enough air in the cooling system keep the coolant from being sucked back into the radiator? Could the fan clutch not be engaging at a low enough temperature? If the radiator is a 2 core, would that cause the coolant to boil enough to cause an air gap that would then keep coolant from being pulled back into the radiator? This truck was originally purchased new by my grandpa in 1991. He was a mechanic and took amazing care of the thing (all receipts). My Uncle purchased it from him a couple years back and I believe it was just sitting on his property for most of the time. -
Recently (9 and 10th Oct.) had a drive with my friend (2008 Ford E-350 with 6.0 diesel) in Eastern Sierra area, used route CA-88(Stockton - Alpine Village), 89(Alpine Village - Topaz Lake), 168(Bishop - Sabrina Lake), 120(Mono Lake - Manteca), US-395(Topaz Lake - Bishop), Virginia Lakes Rd. The highest altitude was 9900+ ft at Virginia Lakes, and had a one-night camping at North Lake at 9300+ ft. The performance is expected, it performs like a mid or early 90s Toyota Corolla with 4 adults on board. At the climbing on US-395N, north of Bishop, (37°28'56.9"N 118°34'52.5"W or 37.482478, -118.581256 ), it can barely maintain 70mph, with the stupid and annoying transmission jump between 3rd and 4th gear. I believe it can actually maintain 70mph without problem if the transmission doesn't mess it up. I am planning to convert it into switch-flip manual or use stand-alone controller. And the climbing on CA-168 is really a struggle, barely 40mph, with the stupid and annoying transmission again, jumping between 2nd and 3rd gear, until I have it enough, simply put the shifter at 2, let it revs at 3500 rpm, while 4000 is the red line. So is it performs normal? Any advice on high altitude driving and tuning? Like base ignition timing? The first day, the climbing on CA-88, 89, 168 and Virginia Lakes Rd, my new air filter is higher than original slight a little bit, caused the air cleaner lid can't seal, let hot air in engine bay get sucked in, I guess it's probably make the high altitude air density problem worse. The next day, I made a gasket with shop towels to seal the lid. I feel it performs better, but since I was grouped with my friend, I can't do the test on the same route to see if it really make difference. ========== My vehicle: 1994 Chevy Suburban K2500 Silverado, 454TBI (L19)+4L80E, with towing package, 178k miles. Purchased used at 150k miles. Engine was rebuilted at 75K miles, which is the only known thing, assuming other things are stock, transmission and torque converter are factory original and weresn't rebuilted. New air filter, Engine oil changed at 175k (Mobil full synthetic), transmission oil changed at 150k. Coolant / water is 60%/40%, new radiator cap, no boil happened. (Prestone for GM, orange color) New spark plugs & wire, ignition coil, ignition control module, fuel filter, fuel pump, thermostat at 150k (right after I purchased it). //edit: O2 and MAP sensor are also new, ACDelco. Base ignition timing is 8 BTDC, factory is 4. Load: 1 person (me), camping gears, road emergency kit and 2 boxes of tools for emergency, no trailer. Fuel: Chevron or Shell 91. -
Can a 454 W engine code bloc be used to replace a N code bloc? I have a seized up 454 N TBI engine and a good running 454 W 4bbl. I just want to swap blocs and keep the TBI running. It's in an early 90's motorhome and it's just to keep it running around THanks all
-
1994 Chevy Suburban K2500 454TBI Mileage=155,000 Factory setting: 4BTC Everything is stock. Searched on internet, looks like some people set it at 8BTC or even 12BTC to get more torque and better MPG. But seems like different year have different program, same setting on some year it runs good, some not. I only use #91 gas from Shell or Chevron. #91 gas allow more BTC, right? Anyone have recommend about BTC setting? Most time running light, only me in it with some tools weight no more than 100lbs. On a test run from San Jose (CA) via I680N, I580N, CA120E, CA99S, CA140E, to Mariposa(CA), cruse at speed limit, most 65MPH, CA140 is 55MPH, most flat, get 13MPG in average. Plan to tow an utility trailer with a fully loaded truck camper on it (I live in the camper).
-
When traffic light turns green, I kicked the throttle pedal, finally, this time, I got the power that a 454 supposed to give me, I almost cried. ======= 1994 Chevy Suburban Silverado K2500 454 L19 TBI 4L80E 153K miles ======= Months ago, I posted several topic (2 or 3) about it stall and knock sound under the floor, while cruising on highway. Well, the "highway" include GGB (Golden Gate Bridge).? 94' 454 stall while driving and knock sound under the cab 94'454 stall again, after change fuel pump Take note that I am actually completely a newbie, new driver (2 years), new vehicle owner, and new to America. So maybe some thing in my topic is wrong, but I don't tend to misleading. Shattered catalyst After the GGB stall, I found its power is weaker than before, and sounds like the exhaust is blocked, and when drive next to a vehicle or wall, I can hear air bleeding sound. Then got MIL code 32, EGR, however I can't find any problem on EGR system. This 454 engine use Linear EGR system, the valve is controlled by ECM directly, no vacuum pipe. I tried to remove air filter, to make it performs better, then find the blocked-exhaust sound become louder. Then one day the stall happened again, I found the knock sound sounds more like opening a soda can. So I visited a muffler stop, turns out the catalyst is shattered, quite big loss. ? Since I don't have enough money for a catalyst, and it may be shattered again, so I asked them to put a steel pipe instead as a temporary manner. After that, the compressed air sound is disappeared, the blocked-exhaust sound is lighter but still there, and the performance is better but still weak. So shattered catalyst blocked exhaust, caused air bleeding sound. And caused extremely high pressure in EGR system, too much exhaust injected into intake manifold when EGR is open, caused ECM think EGR have problem, light MIL and sending code 32. Fired chip in ICM (ignition control module ) The last time it stalls, at a quiet place, I finally figured it out that it feels and sounds like wrong timing, and when press throttle pedal, it back fires, and the harder press the pedal, the louder the sound is, very loud. And when it back fires, I can feel shock on throttle pedal. I told this to my mechanic, he told me to replace the ICM. He said back to old days, he replaced many of it. He suggested me to purchase new one, because it's cheap, even from ACDelco, and this thing usually break down for years parked vehicles, vehicles in junk yard usually parked for years. I opened the metal cover of old ICM, find one of chips is black, oil or something around it is dark brown, the metal cover supposed to be glued to the plastic shell, but the gap near the black chip is open, so it's clear that the chip was exploded. After I changed the module, 3K+ miles so far, including 2 round trip from San Jose to Yosemite, stall never happened, I think the stall problem is officially solved. So the broken ICM caused wrong timing, and stall. "Knock sound" is actually backfire, the exhaust is under floor, so I felt it's knock sound under floor. Back fire caused huge pressure burst in exhaust, then transferred to intake manifold and throttle body via EGR system, caused shock on throttle pedal. Thank god this didn't ignite the gas-air mixture, or my trouble gonna be bigger.? Wrong base timing That's NOT all folks! I found it still very weak, on I680, the climb at east of Fremont, it even can't maintain 60MPH! WTF?? At this time, what I have done on it: Fueling system: New Delphi fuel pump, capable of over 60PSI; New fuel filter, ACDelco; Fuel injector, tested and cleaned; Fuel pressure regulator, changed new spring, 30PSI; Air intake system: New air filter, ACDelco; Ignition system: Distributor cleaned; New ICM, ACdelco; Full assembly of distributor and ICM from junk yard as spare part. New spark plugs, wires and ignition coil, ACDelco. Cylinder pressure: I forgot reading, but within normal range. I pulled out the distributor for cleaning and ICM change reason, but when I put it back, I tried to find the timing mark. However, only engine block have the mark, the distributor don't have mark from factory, only a mark made by the ex-owner's mechanic, and it turns out it's wrong. So I tried to do base timing. I borrowed ignition timing light from my mechanic. But I can't find the "timing connector". At that time, I thought cold start and idle is running at base timing. So you guess it, runs over 20 degree ******. Then one day, I read my shop manual carefully, find out cold idle is NOT base timing, and only when the "timing connector" disconnected, the engine runs at base timing. However I can't find the connector, then after some dig on internet, I finally find it: inside the cab, passenger side, by the side of the blower motor, a single pin connector, tan with single black stripe lead, that's it. It's a bit far from "adjacent to the distributor".? Then I borrowed the timing light again, do the base timing, hit the road again, the result, on I680, maintain 70MPH easily, like I write at beginning of this topic, I almost cried! Just recently days, it even reached over 90MPH when climbing! Yeah it's speeding too much, but you know the traffic flow on highway is a bit crazy after reopen, probably due to people lock in their home for too many days. ======================================================= So That's all folks, I currently focus on renew my truck camper, including solar panel, painting, bathroom convention, jack system rebuilt, then maintenance on the 1996 Ford F250xl, 350 engine, and convert to dually, create a "FAKE F350". ? Then come back, I found the A/C compressor is dead, my mechanic suggested me to get one from junk yard, because most of them from car part shop are rebuild in China, you know what, even I am Chinese, I always avoid "China".?
-
454 Vortec Tapping and Knocking
RW22 posted a topic in 1988-1999 Chevrolet & GMC C/K GMT400 Platform
I have a 1997 k2500 Suburban with the 7.4 vortec. It is a 290,000 mile engine and I was recently doing some work to it. I put new injectors, valve cover and upper intake gaskets, distributor, plugs, wires, and a fuel presssure regulator. This engine was fine before and the only reason I had done this work was because it was cranking for about 5-8 seconds before it would start. When I put everything back together, I got the timing as best as I could (I do not know how to properly time these newer engines) and started it. Immediately, the engine was shuttering and I could hear what sounded like a lifter tap. It was idling very rough and after about 4-5 min a louder knocking sound started up. I immediately cut the engine and checked the oil for metal, and there was none. I am simply baffled at this as I didn’t touch anything when I had the valve covers off. My only two ideas are this. 1) it is not timed right, and I need to figure out how, or 2) the old distributor had some wear on the gear, and possibly the cam has the same wear and isn’t working right with the new distributor. Any help on this would be greatly appreciated. Thanks. -
Golden Gate Bridge, what a perfect place to have your vehicle stalls on. ?? ======================== This is not the 1st time it stalls, see: 94' 454 stall while driving and knock sound under the cab ======================== Before this fault down, I have changed the fuel pump (thanks to <riverbanks>), the original one is weak, I can easily block the fuel pipe with thumb, I think it is almost fail. Changed a new one, very strong, I can't block the fuel pipe with thumb. ======================== Model= 1994 Chevy Suburban K2500 Silverado Engine= 454 TBI Transmission= AT Fault down des. : Location= Veterans Blvd. tunnel NB, Golden Gate Bridge(GGB) NB, Alexander Ave. NB, Calif.; Transfer case pos.=2H Coolant temp.= around 210(heated up), normal operation temp., enough; Engine Oil= normal pressure, enough, just changed (incl. filter); Trans. oil= enough, just changed(incl. filter); Fuel= enough, #87 from Chevron or Shell, I only fuel my vehicles in these 2 brand, I've burnout old fuel, now is new fuel in tank; Symptom= engine stall, hear knock sound from under the cab. Veterans Blvd. tunnel: attempt to shift to N then crank, crank no start, stop on drive way (no emergency stop area) shift to P, crank, start, shift to D(O/D Off), continue the road. GGB: multiple time of stall, after some times of stall, found the engine sounds like intake or exhaust jammed, and very weak power. Alexander Ave.: stall when down hill with O/D off, but back normal later. Inspection at break down site: Air cleaner is okay, filter is new, fuel pump relay contact is okay. Inspection at home : OBD scanner get DTC 54 and 32. ===== Current status=sounds like intake or exhaust jammed, and power is weak; when drive next to a wall or something, can hear the sound like bleed pressure of a tire, this sound can't be heard when the vehicle is not moving. I gonna check ignition system, incl. distributor, coil, spark plugs and wires, to check if there are any bad contact, but I suspect bad contact can't cause this problem. I am afraid one more thing have broken while on GGB .??
-
Model= 1994 Chevy Suburban K2500 Silverado Engine= 454 TBI Transmission= AT Fault down des. : Location= Albany, Berkeley, Calif., I80E; Trans. pos.= D (O/D Off); Transfer case pos.=2H Last operation= OD --> D, fully release throttle pedal; Speed= around 40 mph; Coolant temp.= around 210(heated up), normal operation temp., enough; Engine Oil= normal pressure, enough, just changed (incl. filter); Trans. oil= enough, just changed(incl. filter); Fuel= enough, #87 from Chevron or Shell, I only fuel my vehicles in these 2 brand, I've burnout old fuel, now is new fuel in tank; Symptom= engine stall, hear knock sound from under the cab. Attempt 1: shift to N then crank, crank no start, pull over, shift to P. Attempt 2: crank, start, shift to D(O/D Off), accelerate, around 40mph, stall and knock sound again, pull over, shift to P. Attempt 3: crank, start, shift to OD, accelerate with little throttle, around 40mph, stall with knock sound again, pull over, shift to P. Inspection at break down site: crank, start, noticed check engine light is on, press throttle pedal to 2000 then 3000 rpm, no knock sound, inspected engine driving belt area, belt and all pulleys are okay. Inspection at home (Towed): OBD scanner get DTC 54. Inspected drive shaft for both front axle and rear axle, no loss. Repair attempt= Change: fuel pump relay (as DTC 54), spark plugs, ignition wires, ignition coil (noticed serous oxidation on the terminal to distributor), all from AC Delco, OE or above product line, purchased via O'reilly or Autozone store. Clean: distributor, all terminals (outer for ignition wires and inner for roter), rotor. Current status=normal. Other info. maybe useful=I found a maintenance label on wind screen, its next maintenance supposed to be on 05/22/2014 at mileage 153,000. But now is early 2020, 151,000, so most time it was just sit there. Question= Is this only the fuel pump relay? What is the knock sound? Is there any thing I should inspect or replace a new one?
-
I have a 1993 k3500 454 NV4500... The engine is a semi fresh rebuild(50K miles) with a small cam. I have replaced the following some parts multiple times... The truck has a stumbling rough idle. Seems to lack power to me but im not sure. If i take the truck for a short drive when i come back and go to instantly restart it has no fire from injectors....hit it with a little ether and shes up and running again. Im fairly positive i have that narrowed down to a weak oil pressure sensor.(changing it tomorrow). The truck runs pig rich and never seems to go into Open loop.(i think heated 02 will change that). I AM OPEN TO ALL SUGGESTIONS.. out of ideas myself. I have a ALDL cable with WinALDL & Tuner pro rt but quite frankly do not know what i am looking for I have attached a copy of my logs at a idle. https://docs.google.com/spreadsheets/d/1ZuvfldSA_rejBc0FAmCb38zTbHMIlfNR4CoTWgblQSU/edit#gid=361545408 Parts replaced less than 300 miles ago.( All new with AC Delco parts) Completely Rebuilt TBI unit with 2 inch spacer New TPS & IAC i did my best to calibrate them New map sensor Pickup Coil ( Timed at 4 degrees BTDC with connector unplugged) Cap rotor & Plugs & Wires ICM Ignition coil o2 sensor ( Re wired from ecu wire was broke assuming when they reinstalled the engine) *** I plan on switching to a heated o2 due to my long tubes. CTS Knock sensor (Wire was also broken) Newer fuel pump & Filter 15k ago with all new lines Im sure there is plenty others im forgetting. The EGR is deleted as are all other vac lines except MAP,PCV. I am at my wits edge with this truck but i love it very dearly. Hopefully the geniuses on here can help me figure it out. At this point any direction is better than none. Thank you very much you can email me at [email protected] Or text me at 724-570-8672 if that is easier. Lucas Picture of said truck causing me all this heartache
-
My 1999 GMC K2500 after I swapped the old steel wheels to 2003 Duramax aluminum wheels. HUGE difference!-
- 1
-
-
- big block
- 7.4 vortec
- (and 3 more)
-
My 1999 GMC K2500 after I swapped the old steel wheels to 2003 Duramax aluminum wheels. HUGE difference! -
My 1999 GMC K2500 after I swapped the old steel wheels to 2003 Duramax aluminum wheels. HUGE difference! -
1978 1 ton BBC low miles, body beat to *uc&. 2015 HD2500 hauling her to a hopefull resurection.© GeoJohnny
