Power Problems

[4zstracker]

Hi. Just wondering if anyone could help me with a problem that im having with my 1996 geo tracker. The thing is that it hesitates really bad, and it lacks power. Off the line I have to feather the clutch and rev it to about 2500 just to get it to move, and then it continues to bog and fuss, acceleration is very slow. I have tried quite a few things already. I have given it a full tune up, checked the fuel pump, changed the fuel and air filters, it has new plugs and wires, when i changed those I did a compression check, it checks out just fine, I cleaned out my throttle body, Ive cleaned the EGR valve, I just changed the TPS, all with no result. But the really odd thing is that it comes and goes, sometimes it will run just fine, but most of the time it lacks power and hesitates. Any ideas would be really helpfull, thanks.

[jtgh]

96 , 1.6 Liter or 1.8L sport?


is your check engine lamp glowing or flashing?

have you modified any of the Induction, EFI or other engine controls.
like : cold air pipes, exhaust, etc.?
does this every happen on a COLD engine or only HOT?

engine sounds lean. (or EGR sticking open, too)

One guy had a crack in the air pipe from the MAF to the TB and only leaked during heavy torquing of the engine. One guy had the clamps missing. one guy had cracks in tube, other had broken pipe resonator.
I'd examine this tube very carefully.

Any AIR leaking UP STREAM of ANY MAF is bad news.
up stream is towards the TB.
Flow:
engines see x air as reported by MAF.
but engine is really getting X+ 5 air.
so ECU , mixes X amount (14:1 by mass) of Gasoline.
Mixture is now lean.

I saw one guy build a RAM air in to his Air cleaner,
his MAF when totally Crazy, I could not deal with that.

Do every thing you can to make that MAF happy and you will be good.

Hint: MAF only works when engine is hot.

thus my question about Cold.


powerloss


there are other possible things, and are more difficult to diagose:
clogged injectors , not likely to be intermittant.
clogged fuel filter , pressure ok, but volume , very low.
Fuel pressure regulator bad. (stuck at low pressure) on fuel rail.
bad gas.

i do not think it is spark as that causes BUCKING.
and p0300 or close to set in CEL DTC.

if fogot the most imporant help.
this is an OBD2 car!
you can connect a datalogging scanner and watch the real time
parameters of the engine. Like Short and long term fuel trim and
open or closed loop mode working, and OXY ops, and a host of other values.
This car would be easy to diagnose with the much smarter ECU.
Some places rent them. Autoxray is one.
I use a Harrison Eng. that loads to a PALM. < one of the best >
I can look at anything as a METER or as a SCOPE. way cool.

[jtgh]

sorry for long post but Powerloss is the BIGGIE.

[tracka96]

One easy try to see if you have the fairly common worn timing belt drive pulley and keyway: temporarily advance your timing to about 18 degrees, drive it see how it runs. Tracka

[4zstracker]

Its a 1996 2 door, 1.6L, 4x4, 5 speed. Its all stock, no modifications, as of yet. This happens both cold and hot. But it also idles normally both cold and hot most of the time, occasionally when it is hot the idle speed will drop to about 500. I have checked the intake tube and it looks good, I also cleaned the MAF sensor, with no result. The entire MAF/ intake system looks happy. I have also checked the entire fuel system, minus the fuel injectors and fuel pressure regulator, and it all looks good too. Any possibility of an electrical problem? I noticed that when i disconnected the TPS and moved the wires around then sometimes it would run OK for a while. The #4 fuel injector is right next to the TPS in the wiring harness, could there be a short there? Oh and when i had the new TPS connected the CEL came on, but since it didnt make any difference i put the old one back on and the CEL went off.

[jtgh]

If one injector fails (elect. or inj fuel block) engine runs very rough , you would know it right off.
if you lost spark (on and off) car would BUCK.
off =\die, on/off buck, ON runs perfect. IGNTION.

No cel light , but a good code reader can give you vastly better picture. (logging). including Pending codes !
If an injector opens , it sets a CEL , if the ignition misfires , it sets a CEL. P300 group.
Open TPS , sets Cel. and a host of other monitors.

I presume this is an OBD2 car, with DTC 16 pin connector above drivers right knee?
if it is , you are missing out on the best troubleshooting help in the world "OBD2".


Crank key way problem. IMHO:
Try to tighten the Crank nut to spec. if it doenst need it then its not a problem , if it moves , during torque
procedure then worry.
If worry pull it and look .
If you even THINK this problem is real , then park the car , dont drive it and inspect this area.
Just like Tbelts on 16v , dont drive it , look first.

like a doctor, first, do no harm.

Ok lets get over this crank issue.
easy:
1:
pull #1 spark plug
2 insert 12" heavy tyewarp tie in to #1 hole.
3 rotate crank with socket wrench CW until you feel the tye wrap hits TDC, now look at timing mark
do they agree, ?
You can buy a special tool that does this , that screws in to the spark hole , looks like a tire guage , the kind not Bordon but a flat blade with index marks.

repeat test 3 times and make sure TDC 0 is dead on.
then we can go back to fuel and air.
you are missing fuel. ( if no vacuum leaks is true)

[toya]

Hey, you seems to know the most about Vitaras.
What kind of program will I need for my laptop to get the datas from my 96 Vitara (scandinavia mod) and what kind of connecting cables?

Mvh
Harald
Norway

[jtgh]

hi toya;
if you want cheap , just code reader, go to harbor frieght dot com.
$29
if you want to data log and see all live data go to.

here
I use this on a palm
OBDScan

but it runs on PC or any lap top (ms windows based)
very cheap but very POWERFUL.

[4zstracker]

Just an update on the original post. This morning my CEL came on and has been on since then. Yesterday i checked all of the electrical connections for the fuel injection, and they all look good, so no problems there. And I also went through and leak down tested the whole vaccum system again for the 3rd time and still no leaks. This is a really frustrating problem, because this is my daily driver.

[jtgh]

pull the DTc code/S , why be blind ?

YOU ECU IS CRYING < PLEASE LISTEN !

why not?

does yours have a Distributor cap or those COIL on plug coils.???

Those Coil on plugs are famous of leaking.and throwing code P0300 or very close.