Sierra :: 1991 GMC 5.7 Surging While Driving At Constant Speed
Apr 26, 2012
This truck has 180km on it and runs fine except as of lately i have developed a surge while at constant speed. When i step on the gas it does not seem to happen.....it only happens when I reach a constant speed. The odd time it will surge at idle and the engine will rev up and down on its own also. When at highway speed it seems to not do this. The truck never dies completely....just surges slightly.
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I have a 1991 celica gt 5sfe hatchback. I am getting a surging at constant speed, at idle it's fine as well as acceleration. It only does it when trying to maintain a constant speed in the range of 10-50 mph or so. It's feels like I'm pushing the gas and letting off repeatedly. I took it to get an emissions test and it failed on the low side test with high co2 reading, everything else is fine and one place couldn't do the test because the surging kept kicking the computer out since they have to keep it at a constant 15 mph speed. I think whatever is causing the surging is causing me to fail the low side emissions. Could it be the iecu?
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I have an 04 Elantra GT and have been noticing a jerkiness when driving at a constant speed on the highway. I haven't noticed it around town or while accelerating. I also have noticed that when I disengage the clutch on the highway, the engine sometimes doesn't respond right away, or it even may surge. This has happened when exiting the highway when I disengage the clutch. The engine will slow, then speed up close to 3000 rpms.
I also had a check engine light come on and couple months ago. The code indicated that the upstream O2 sensor was bad. I took it out and cleaned it, but didn't replace it. Is this a likely culprit for this set of symptoms? If so, how can I test the sensor to be sure? I heard that I could disconnect it and run the car and see if the surging lessens, but wasn't sure if that was a good thing to do.
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This weekend I was driving home from my parents and noticed that on flat ground at a constant pace there seemed to be surging of some sort...Although I am not sure that surging is exactly what it was, but it is the best word to describe it.
Basically, if I kept my foot at an even speed (not accelerating or decelerating) I would get very subtle movement in what seemed to be either the differential or the transmission. No error codes were thrown and the battery gauge was spiked at 14 solid.
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I recently had intake manifold gaskets replaced in my 98 gmc sierra 4x4 pickup 5.7 . The day I drove it home from the shop it ran fine, even day after but the next day I noticed it seem to idle a little rough and even at normal driving, sometimes seems worse than others. No service engine light has yet to come on. Could there be vacuum leak, trash in intake or bad wires and plugs. Plugs, wires, rotor button and distributor cap are only year and half old.
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A few days ago my 98 C1500 started having what I can only imagine is some type of torque converter issue. While driving at a constant speed the RPM will surge by about 500-600. This surge does not coincide with any type of acceleration, it's more like the converter is letting go and the RPM's just rise and fall back down. The fluctuations also seem to stop after about 15 minutes of normal driving. I have had no real noticeable transmission issues. At first i assumed it was my tranny fluid just breaking down so to get me home I used a bottle of Lucas.
The bottle seemed to do the trick for only a couple of days and now the problem is back...no better, no worse. The only difference I have noticed is that before the addition of the Lucas my fluid looked perfect and now it seems there is a bit of varnish. No smell, nothing seems burnt, just a little dirty. I haven't changed the tranny fluid for about 70k and the truck now has roughly 160K on it. My concern is that if I do change it the transmission will crap completely and I'll be on the hook for a rebuild.
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I have a 2002 camry with 212000 miles on it and just lately when driving at a constant speed 60 mph or over it starts to buck or jerk a little bit and you can feel it in the seat. I've had the throttle body cleaned and put in a new mass air flow sensor and it hasn't fixed it yet. What might be causing this? It doesn't do it when accelerating or slowing down.
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We have a 2003 Passat GLX, 43000 miles, V6, AWD. I've noticed recently that when driving at constant speed the engine will surge about once every second or two. It's very regular, and on a smooth road I can also notice a bump in the drive train, very similar to road bumps.
I've taken it to a dealer, since I believe it is a transmission issue, and therefor covered under warranty. There are no computer codes stored for faults in the transmission, they've said. However, they started by pursuing the fuel injection system (though no code was stored), and then wanted to fix a faulty coolant sensor (since found not to be faulty).
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My 1996 Honda Accord V6 has a stuttering problem. It only happens (or is only noticeable) when driving at a constant speed. It is most noticeable when driving in the 45 - 55 mph range. It feels like the engine has millisecond breaks in power. And this does not happen all the time. Some days, it drives just fine with no problems. It idles fine. The problem is not noticeable, if there at all, during acceleration.
One other piece of information that might - or might not - be relevant is that the tachometer seems to be out of its mind. It bounces all over the place up and down. This also does not happen all the time, and it seems to me, though I'm not 100% certain, that the stuttering problem only happens when the tach is crazy..I have had no luck getting a mechanic to diagnose the problem. They claim the tach problem is totally unrelated.
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my 2006 GX has 95000 miles and recently i've noticed a slight hesitation followed by a slight surge in speed while driving at a constant speed. it almost feels like i'm pushing the accelerator then releasing it. its a very mild difference but i'm guessing tranny and have 5k left on my warranty. it occurs at a variety of different speeds but most noticeable at about 35-40mph and up around 55mph.
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I have a new 2015 Subaru Forester and I noticed the following problem: When driving at a constant low speed, in the 20-30 MPH range, the car bucks/hesitates slightly off and on, while driving. At first I thought the engine was missing, but I noticed the RPM was at about 1000 RPM, very low. And a missing engine would cause a "check engine" warning.
So I think this is a combination of the CVT and the engine lugging. The CVT should move down a notch to a lower "gear" but it doesn't, so the engine is forced to operate at a problem speed. A normal transmission would downshift, I would think.
Can I do anything to solve this, other than manually shift to the low range?
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Recently it feels like the transmission is 'hunting' drops a gear, picks up a gear when driving constant speed on flat roads. 2.0T with tiptronic. Additionally, very intermittent, the car will get a shimmy around 48-50 mph. feels more transmission related and it is not the tires since it is an intermittent issue.
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I have a 1994 gmc sierra 4x4 5.7 with a rebuilt engine 2 yrs ago and it has started having a rough idle(surging/dies) I have replaced fuel pump, fuel filter, maf sensor, iac sensor, tps sensor, top half of the tb and injectors, distributor, ignition module, plugs and plug wires and still no change. Yesterday I cleaned the iac and seemed to straighten up a little but then got in it to go to work today and it was back to running rough again and seemed worse. I am at a loss.
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I recenlty bought a 98 GMC sierra for a great price knowing it needed engine work. It has a constant misfire on cylinder one and it causes the whole truck to shake constantly no matter whether idle or acceleration or slowing down. At first I was thinking a burnt exhaust valve. I ran a compression check (the engine was cold though) and I heard a cold compression check means nothing. But in doing so I found that cylinder 1 has the highest compression out of all. I plan on another compression test tomorrow when engine is warm. But until then I was thinking maybe a bad injector on cylinder one? It is a "spider injection system" and I was wondering if it was possible for one injector to be clogged or not working and the rest be fine. I have seen where one will get hung up and cause hydrolock.
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I just purchased a 91 sierra sle with the short bed. I am interested in buying a cap for it because the snap on tonneu cover is falling apart and id like a cap. Would caps from other full size short bed pickups work or does it have to be from a sierra/silverado?
Also i notice the oil pressure fluctuates from around 20 to 80 depending on if I am idle (20) to acceleration at 80, when driving it seems to go up and down to depending on the accelerator position. is this normal??
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I have a 1991 gmc 1/2 ton with 200K on it. Its a 350 engine. The engine has been stumbling for a long time. I've tried many things ...new fuel pump and filter...complete tune up.....checked all vacuum lines..replaced a couple lines...EGR valve.....changed head gasket and intake gasket. Checked the warm up flap inside the air cleaner. I am now very very frustrated.
This stumbling happens often but intermittent also....sometimes worse than other times like the truck is about to stall. The truck seems like its being held back like a loss of power. The truck will begin to stumble so i will pull over and rev it up and it seems to clear itself for a short while then right back to stumbling.
Upon warmup in the morning she seems to run fine until hot. No codes being thrown ...service engine light NOT on. Even while at a stop i will hold the throttle part way and revs at different rpms. I am now at a loss and feel defeated.
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My f350 6.0 has seem to have lost its power, while I was driving home it would only accelerate at one constant speed, and driving up hill it would not accelerate at all, I also noticed an elevated exhaust temperature.. There are no warning lights or dash lights indicating any problem.....
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I'm working on getting my GMC seirra 1500 5.0 L running. Last fall When I was making a trip to another town, it broke down. When it broke down it smelt like plastic was burning, I was unable to figure out what the smell was.
First I though it was a bad battery connection, or that the starter had went.
I changed the Battery, made sure the cables were good. changed the starter and it still doesn't work.
I know the battery is working for sure because There is power to the lights so I can turn on the brights. There is no power to anywhere else on the dash though other then the icon that shows the brights are on.
When I try to turn the engine over, nothing happens at all. Doesn't even make a clicking noise.
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I just bought this nicely used 1991 GMC Sierra 1500 series pickup truck for $650. It started up and ran fine when I gave the seller the money - the few leaks in the break lines.
Easy fix right!
So my son (19 that knows it all) and I went and changed all the brake lines (made everything one size 3/8 line.) Filled it up with break fluid and started the truck. I had my so pumping the breaks and holding them (his first time) I bled the far rear (passenger side) then I had him turn the steering wheel to the right so I could bleed the front driver side.
He turned, and turned and turned until the engine died.
Now the truck only runs when the steering wheel is turned all the way to the right or all the way to the left.
Going to pull the codes to see what the heck is going on....
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1991 Honda Accord DX A/T A/C. The engine is surging/searching at idle in park and in neutral from 1000 up to 2400. There are no engine fault codes.
I have cleaned the IAC, adjusted the TPS, Removed/Cleaned/Re-installed the TB, No MAP problem. I also removed the "black box" and checked the cold idle control diaphragm as best I could. I cannot find any specs on testing this. When I apply vacuum to it via the center port on the bottom it holds the vacuum, but takes approx 5 seconds for the diaphragm to "pop" to its ambient state after releasing vacuum.
I have sprayed all possible vacuum hoses along with all intake gaskets to test for vacuum leaks.
I have attached a diagram of the black smog box that is mounted on the firewall. The cold idle diaphragm is labeled as 2. I also have concerns about that electrical vacuum solenoid labeled 27.
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1991 Ranger STX, 4.0. Had a leak from the rubber seal on the thermostat. Changed the thermostat (stat 195) and seal. Now my temperature gauge is not showing a constant reading, goes to half way and when the thermo opens the gauge falls down to a quarter. The gauge is cycling this way every time the thermo opens.
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