Gt4 Power Trouble

[Severn]

Hi Guys and girls..........

I have a problem that I am struggling to solve...... I have a 1995 Celica GT4 that can't put the power down properly. Very very lumpy when cold and kinda bunny hops when you put your foot down.

When up to temp it is a lot better but still doesn't have the power it should, nothing like the others as I have had a few of these, It is totally standard except for an induction kit. The only other problem I have is when driving the car at steady speeds the heat gauge drops down to cold again.....is the temp sensor connected to the ecu and poss causing the running problems???#

I have checked all hoses and they appear to be good and as they should be. The Turbo also appears to be nearly new!!

Has anyone had any smilar running problems to this that were able to cure???? Hopefully without me running around like an idiot trying to find it or paying someone a fortune to check............

Many thanks all and hopefully you can help

[markd1984]

an old celica st185 that i had, had a very similar problem and it ended up being the ensor that was on the airbox had worked its way loose so when it did run it was awfull its a long shot but worth a look! as for your temp gauge i have the same problem with my current st185 now, if sat still it rises to half way but when driving it drops to just above the bottom line and i have put this down to the thermostat. other areas would be to look at your dizzy cap, leads and plugs.

hope i have been of some help with my limited knoweledge

[Severn]

an old celica st185 that i had, had a very similar problem and it ended up being the ensor that was on the airbox had worked its way loose so when it did run it was awfull its a long shot but worth a look! as for your temp gauge i have the same problem with my current st185 now, if sat still it rises to half way but when driving it drops to just above the bottom line and i have put this down to the thermostat. other areas would be to look at your dizzy cap, leads and plugs.

hope i have been of some help with my limited knoweledge

I thanks for the reply!!

I checked the air flow sensor thats in but not sure whether it is operating could have been bodged when the induction thing was put in so I will check a bit more on that!! Done dizzy leads etc and that didn't do anything!! Just seems to be baffling me!! nothing ever simple on these things!!! I wouldn't mind I am selling it but don't wanna leave it as it is!!

Keep the ideas coming as I will need to check just about everything I think!!

[markd1984]

have you checked for error codes?

[Severn]

Someone at a garage apparently checked, not sure whether I believe or not, but came back with intercooler code...... but nothing specific! Gonna try and check tomo with a friends diagnostic equipment.....Has anyone got a list of fault codes? or a sticky on here?

[markd1984]

if you go on the gt4ec forum in the how to section it tells you how to do it and what each code means

good luck

[gezmeister]

Here's a list of error codes and what they mean

Code Description What to do?

12 - RPM No G1, G2 or NE signal to ECU, open in G- circuit Starting related, check distributor, starter, ECU. The dizzy is connected to the loom via a plug awkwardly placed under the dizzy - check this, and the dizzy wiring

13 - RPM No "NE" signal to ECU above 1000 rpm Check distributor, ECU

14 - IGN No "IGF" signal to ECU 8 times Check igniter, ignition coil, ECU and IGT wire to igniter. Can be caused by wire feed into the coil. The IGF signal is fed back to the ECU to inform the ECU that the igniter is "ok"

16 - CPU ECU duff Repair or find a new ECU

21 - O2 Detection of oxygen sensor deterioration Check oxygen sensor

22 - WTR Open or short in Water Temp Sensor Check/test Water Temp Sensor and wiring

23 - MAT MAT Fault Check intake air temp sensor connector and functioning correctly

24 - AIR Open or short circuit in Air Intake Temp Sensor Check Air Temp Sensor within intake filter housing

25 - O2 Excessive Lean Air Fuel Ratio Check O2 sensor, fuel system. Replace fuel filter. Check FPR connection and water temp sensor

31 - PIM Open circuit or short in MAP sensor Test or replace MAP sensor

34 - PIM Fuel cut due to excessive turbo pressure Check Wastegate, Wastegate actuator, Wastegate Hose, Turbo Pressure Sensor

41 - TPS Open or short circuit in VTA signal Test Throttle Position Sensor - article

42 - SPD No "SPD" signal over 8 seconds driving Check Vehicle Speed Sensor, SLD (if fitted) and wiring

43 - STA No starter signal over 800 RPM starting Check Ignition Switch

51 - A/C Aircon malfunction Check Throttle Position Sensor - article

52 - KNK Open or short circuit in Knock Sensor Check for broken/brittle wire, check sensor correctly torqued up, check sensor terminal not covered with oil/shorted out, replace sensor, shake sensor - it shouldn't rattle! There should be no continuity between the centre pin and the body of the KS

53 - KNK Knock control in ECU faulty ECU

54 - INT Intercooler Coolant Low or Pump Failure Top up IC fluid reservoir, test IC water level sensor, test IC water pump. Tip - run car with IC cap removed, blip throttle, watch water level drop, add fluid to max level, swiftly replace cap - this indicates the pump runs

If unsure how to check for error codes look on www.gtfours.co.uk and it'll tell you how :)

[GTForbes]

for the temp gague, it could be a busted thermostat or a cold temperature one, IIRC the thermo should have 82oC marked on it.

the intercooler code just means it needs topped up