Hello,

Automobile Forums  Where Car Enthusiasts Go to Discuss Cars Online

Rbdi 800X50Ad Tracking
 
 
Item Posts   

1990 TOYOTA CELICA GT RUNS RICH

 
 | 
larryb50 larryb50
New User | Posts: 3 | Joined: 08/11
Posted: 08/13/11
02:00 PM

THIS IS OLD CAR IN GOOD SHAPE ,BUT RUNS RICCH ALL THE TIME HAS NO CODES NEW PLUGS WIRES CAP ROTOR NEW ECT O2 SENSOR SOME ONE HAS THROWN THE WORLD AT THIS CAR HAS ANY ONE SEEN THIS PROBLEM BEFORE  

waynep7122 waynep7122
New User | Posts: 35 | Joined: 04/10
Posted: 08/16/11
07:07 PM

really... no codes.. and it runs rich/???



1982-95 MODELS


All models  equipped with OBD I till 1995.

Make sure the battery voltage is at least 11 volts.

Make sure the throttle valve is fully closed.

Place the gear shift lever in Neutral. Turn all accessories off.

The engine should be at normal operating temperature.

Using a jumper wire, connect terminals TE1 and E1 of the Data Link Connector 1 (DLC1).

0900C152801ccc5e

Turn the ignition switch ON , but do not start the engine. Read the diagnostic code by the counting the number of flashes of the malfunction indicator lamp.

Codes will flash in numerical order. If no faults are stored, the lamp flashes continuously every 1 / 2 second. This is sometimes called the Normal or System Clear signal.

After the diagnosis check, turn the ignition OFF and remove the jumper wire.

Compare the codes found to the applicable diagnostic code chart. If necessary, refer to the individual component tests in this section. If the component tests are OK, test the wire harness and connectors for shorts, opens and poor connections.  

waynep7122 waynep7122
New User | Posts: 35 | Joined: 04/10
Posted: 08/16/11
07:26 PM

you also did not mention.. if its a 1.6 or a 2.2...

automatic or manual transmission...

california emission or US emission system..

do you have a fuel injection pressure tester??? if not.. some parts stores have them behind the counter in the loan a tool section..

do you have a digital volt meter???? they start at 7 buck.. and you don't need to spend more than 25.. the 15 to 20 buck versions work well.. try to get an automotive version.. as it will have additional helpful settings like   dwell , Ms (milli second) duty cycle.  

things that can cause rich...

clogged exhaust.. cat..   this is tested with a vacuum gauge.. if the manifold vacuum drops as you slowly increase the RPMs... the exhaust might be restricted...

the throttle position sensor/switches fail.. sending the wrong signal to the ECM at idle... so it thinks you still have your foot on the gas...

coolant temp sensors go bad... (Rare on Toyotas)

thermostats hang open.. too cool a coolant will cause it to run rich.

air flow meter contacts go bad... there are tests for this... with an ohm meter...

air flow meter connectors get corroded... ..

fuel pressure regulators fail... leaking excess fuel into the engine... pull the vacuum hose off it with the engine running.. there should NOT be any fuel in the vacuum hose side..

fuel filters get clogged.. reducing the fuel; pressure to the fuel rail.. the engine compensates for this by increasing the ON time for the fuel injectors..   the reason to get a meter with a MS scale.. 1.4 to 1.6 is a normal fuel injector MS time at idle..

fuel injectors clog...  i have had to remove and clean hundreds of toyota fuel injectors..   its complex to clean them...  i have had people pour in HALF a pint of B12 chem tool. into the fuel using a transmission funnel..  and at least 3/4 tank...  then drive the car..

dirty ground wires will also cause problems...
get the engine started.. turn on the headlights..
set digital volt meter to 20 volts D C scale..

test across the battery posts.. 14.1 to 14.8..
test negative battery post to engine block.. 0.04 volts
test negative battery post to body...              0.02 volts
test engine block to body. ...................       0.02 volts..

post what you get...   if you get 0.00.. try turning the meter to 2 volts dc scale... test again.. this only takes about 2 minutes to complete.. post results..  

solidblue solidblue
New User | Posts: 1 | Joined: 01/13
Posted: 01/19/13
09:22 AM

I have a 1990 GT 2.2 L manual, and just rebuilt the engine after 515K miles.  I put it all back together, fired it up, it ran almost immediately, but seemed to be running rich.  After warm-up, took it for a 30 mile drive and had good power, some hesitation and mild roughness here and there, but had no indication that cam timing or anything obvious was bad, other than the smell of the exhaust said "rich", and my mileage was noticably poor.  02 sensor and plugs were black.  No error codes.  I started checking every thing I could think of, including fuel rail pressure, throttle position sensor operation, etc.  

What it turned out to be was my failure to attach the vacuum hose to the almost invisible MAP sensor on the firewall behind the throttle body. From other posts, other forums, this will not cause any error code, but affect fuel mix no kidding!  MAP sensor is not really spelled out in the paper manual that I use, nor discussed, nor indexed.  Hope this post saves someone else a little aggravation.  

Xml
Showbuyersguide Hide
Header Bg
Get a free and easy new car price quote in minutes
Button Seedealerprice