I have a 95 Pontiac Sunrunner,and lately its been idling very high (3000 rpm) for about a minute,and then within the next minute it will gradually return to normal. Its a 5 speed RWD. Ive started to notic that after about 2 minutes everything seems to be back to norman and then it starts to rev up on its own and drop back to normal. It now does this each time its started. After the high reving gets back to normal.It does this reving thing for about half a minute and then its fine.Could this be the carb acting up> or just a vac leak? This reving thing just all of a sudden happened. Gas milage is awful but always has been with it. Maybe getting 45 km off a 1/16th from full. Someone suggested getting (a new to me carb) and that might fix this problem. Truck has lots of power and will spin the tires on dry pavement, but again top end is only like 100 kpm, which is plenty fast enough for the old beater and driver.Thanks in advance for any help
Are you sure it has a carb? These vehicles only came with carbs in very few countries.
Never trust the fuel tank gauge to check your fuel mileage. Variations in the gauge and your eyes always tells lies. The best way to get mileage is to fill up and use the trip/odometer and calculate your mileage to how much you need to fill up the next time.
100 km/h max speed at wide open throttle is pretty slow.
You need to let's us know what type of engine you have and what body style you have before we are able to help. If you aren't sure, a picture can allow someone to identify it for you.
Escudo, '93, 4 door, 16v, 4 spd Auto trans, 4WD, Auto locking hubs
1994 Isuzu Pickup 2wd 5 speed short bed
Your car is basically a rebadged Suzuki Sidekick (as is the Tracker). Where are you located? Your 95 Sunrunner will be electronic fuel injection, not carburetor. So, first advise whether you have the 8v or 16v engine, as some of the mechanics are different.
It sounds like your car has a number of problems, and that one of them is the timing of it. You should do a compression test on the engine, with the gas pedal at wide open throttle while you are cranking, and post your results. You need to confirm that your car is timed correctly (which, frankly, if your top end is so poor, it probably isn't), before you start fixing other things. Timing belts can slip, etc., although it sounds like your issues have been around for a while.
You should also confirm if your check engine light is on with the key on, and off once the car is running. Normally, high idle from vacuum leaks are constant, and don't fluctuate as yours does. However, the idle going up and down is often due to the ECU attempting to regulate the idle, and failing to do so for any number of reasons. Have you done any maintenance on the car?? The car needs to be at proper warm running temperature, as well (and not determined by the dash gauge, but more accurately by an IR thermometer reading taken at the thermostat housing)
And if you are going to check your mileage, you need to do it correctly. How do you determine how much gas you have, only by thinking that the needle is at '1/16' full? Instead, you should fill up your car, drive at least 100 miles, then fill it up again. Then compute your mileage.
Do the compression test first, and then post and start from there.
I have a 95 Pontiac Sunrunner,and lately its been idling very high (3000 rpm) for about a minute,and then within the next minute it will gradually return to normal.
show vin, chassis tag or a photo of engine for best help !
Its a 5 speed RWD. (4WD?)_
Ive started to notice that after about 2 minutes everything seems to be back to norman and then it starts to rev up on its own and drop back to normal.
It now does this each time its started.
After the high reving gets back to normal.It does this reving thing for about half a minute and then its fine.
Could this be the carb acting up>(if a carb sure, they get real bad this old and not serviced)
or just a vac leak? This revving thing just all of a sudden happened. Gas milage is awful but always has been with it.
(means its was always bad,due to no service )
Maybe getting 45 km off a 1/16th from full. Someone suggested getting (a new to me carb) and that might fix this problem.
sure if compression is good, and spark good(try a tuneup) and if the
spark advance still works then , bad carb. (bad fueling )
Truck has lots of power and will spin the tires on dry pavement, but again top end is only like 100 KPH, which is plenty fast enough for the old beater and driver.Thanks in advance for any help
The VIN# on the truck is 2CGBE18U1S6938674 its a 2 door soft top with the basic roll up windows and a radio. NOT a 4x4 just RWD. Trying to add pix to profile, Im not computer friendly, so this may take some time. Have LOTS of pix but theyre bigger ( as in too big) and have to be made smaller in order to post up.
Service: oil changed regularly,air filter good to go. New breaks all round. Clutch new in the fall. Replaced ball joints in the fall. Got the truck in summer, previous owner was owner operator of a garage and suposedly did all the work on it. Ran great when purchased....except for the dash lights that never worked. Still dont!! Its power plant is a 16v 4 banger. new plugs etc. From full tank,I get (according to tripomiter)250-300 KM and by then Im well into the red mark on the gas gauge. All driving is city,and no Im not a lead foot. Im in Calgary Alberta (Canada) Have a large heated garage and tools to fix this with proper direction. Just not familiar with it yet.
ok, it's S code Sunrunner GM. S=1995 2door, 2wd = RWD SURE.
IT'S A 8V TBI THERE IS NO CARB. SORRY, (unless hacked) (put your photos in a Photo bucket or the like and link them)
the dash has a CEL/SES lamp does it glow key on? as poster asks?
U vin code is 8v. 6code is 16v for gm or GMC Pontiac
OP does your glove box (open) door have an GM RPO tag? LS5 is 8v
if yes, (off my vin page)
U= Engine code 8v 1.6L RPO LS5 and 6 VIN= RPO L01 ,16v 1.6L EFI . (out side usa there are over 8 codes and engines)
both the vin and RPo tell engine code, with hood closed
engine valve cover black , 8v
engine valve cover silver , yells 16valves is......
my motor finder is here, is it too hard?
then (bad idle is cover even for your year here)
8v TBI yes, all air leaks on all TBI results in higher idle speeds and full power
pick G16a 1995 here. I got a bad idle , cold or hot engine!
can be just a maladjusted TPS> (idle switch failure, or not calibrated)
or ECU is going in and out of Limphome mode .
vacuum hose cracks , vacuum parts bad. ,TB gaskets bad.
TB= throttle body
TPS is the throttle Position sensor.
coolant not holding 180F to 195F (dash gauge is a useless toy)
Dashpot failure. on TB
see page. on topic above bad idle
I would be checking the EGR valve and the IAC(idle air control) if it has one....I also had a car..truck..tracker that would do the same thing....found the water/antifreeze level to be low and the computer could not get a temp from the cooling sensor...so it didnt know how to keep it idle right...just a thought
Ok gus, this is like info overload for me. I figured I would get MAYBE one reply in about a week if I were lucky. Im amazed at the quick responses...and yes very pleased (really) OK, so this is what I done today. I turned the key to almost start Check engine light comes on,as does Oil and E brake (cuz thats how I park) High beam lamp on dash also works. Flashers on dash work. Speedo, tack,gas,water temp,all work.Nothing else lights up on the dash. Yes I checked all the bulbs,none burnt.All fuses inside truck OK. Started truck,and check engine light goes out.Starts very quick. Idle at 15 hundred (its +6c outside) idle remains steady and begins climbing gradually. Peaked at 2000 and stayed for about a minute then began a gradual decent. I noted the coolant temp comming up as revs went down.Idle settled at a steady 1000 for maybe half a mimute before dropping down to 850. A minute of that and the up and down revs started.This is not a fast reving but a gradual increase,and decrease.As it reaches 2000rpm it drops back down to 850 and begins its climb again. It does this for maybe a minute or more and then it just stays at 850. While this is going on the motor doesnt shudder belch blue,black, or white smoke, or do anything out of the ordinary that would cause alarm.
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