96v6bird

BuzzLOL

.. You're on the right track, mismatching parts just causes problems...

.. The gauge and ECM/computer each have their own sensor/sender...

.. You may also have a partially clogged injector causing lean running and white O2 sensor...

.. May want to read/skim through the "Performance Prom" 'sticky' above for more info on keeping your car tuned for max performance...

ninetyone

iTrader: (2)

You should still go into closed loop fine with a 160 thermo. Your car doesnt run off the coolant temp gauge. The ecm gets its temp readings from the CTS.

ninetyone

iTrader: (2)

To go into closed loop,three things have to be met:
1. The O2 sensor has varying voltage (indicates it is hot enough to operate).
2. The Coolant Temperature Sensor (CTS) is above a specified temp, about 104 deg. F.
3. A specific amount of time has elapsed after engine start.

96v6bird

Well I read somewhere that until it goes into closed loop, the computer runs the af ratio with the coolant temp gauge. My gauge is going bad so I figured this could be causing my problems.

305sbc

iTrader: (3)

That's not correct. Neither the gauge or the sender is connected to your ECM in any way.
The ECM looks at the CTS. You can monitor the CTS output with scanning/datalogging software, or test the CTS with a digital ohm-meter.

The ECM runs the engine in open-loop until it goes into closed loop, or if there are certain errors will run in limp-home mode.

Open loop uses the coolant temp (CTS) to determine the commanded AFR for fuel delivery. Normally open-loop will have you running quite a bit richer than 14.6:1 AFR.

If your O2 sensor is good and you still suspect lean, then I would look at the spark-plugs and check your exhaust with a wideband O2 to confirm lean.
If your engine is lean still, then it is probably due to a mechanical fault.
I would check the fuel pressure first. If that is good then check the injectors.

96v6bird

A friend of mine used a diagnostic tool to scan the car while we drove it. It would run like it should. Go rich lean rich lean, he told me that's normal for these cars. Then at times it would go lean and stay lean for awhile then go back to normal. This was before I switched thermostats and not really sure it ever ran in closed loop cause it ran very cool. Never got over 160-170.

On top of that, the cts is going bad. I'm wondering if it's causing a problem with how it runs before it goes to closed loop.

ninetyone

iTrader: (2)

That has nothing to do with it. You should be into closed loop within about a min or so of engine running. Open loop is a pre-programmed set of parameters in the ecm/chip. Normally in open loop BLM's will stay at 128. Is your car going thru a lot of gas?

ninetyone

iTrader: (2)

I would look more towards a bad o2 sensor and/or CTS.

305sbc

iTrader: (3)

How do you know it's going bad?
A bad CTS will absolutely cause problems with how the engine is running. It should set a DTC code as well.

irocarter

iTrader: (1)

could a white color on the o2 mean coolant is passing by it?

ninetyone

iTrader: (2)

possibly,but to try and check what you are checking, you should be looking at your plugs for any white ashy color. That is not even where u should be looking tho. Test your CTS (refer to the sticky on "testing CTS"),then move on to testing your o2 sensor. This is much easier with a scan tool or a program like TTs Datamaster,Winaldl,etc.

BuzzLOL

.. Also, your temp gauge prolly isn't going bad, it's prolly the sender for the gauge...

.. With the exception that if your instrument panel isn't getting a good ground connection, it could be causing the gauge to fluctuate...

.. So, both the sender and CTS need to be checked to make sure they are changing resistance smoothly with temperature changes...with no open circuit spots...

.. well, same for TPS, as well...

96v6bird

Cant really tell how its doing on gas cause my speedometer is slow, its about 13 mph slow/off. But with the speedometer the way it is it has shown to have gotten around 225 miles to a tank. Mainly in town.
I replaced the o2 sensor 1 time and it actually ran right and then the o2 did the same thing, turned white and started to run poorly.
Honestly I'm not sure. Although here lately the SES light comes and goes. Doesnt stay on but its been coming and then going off within minutes.
I've checked the plugs and my dad seems to think they look good. It's confusing.

The gauge worked when I got the car running and recently started going haywire.

ninetyone

iTrader: (2)

cant you tell by how quickly your gas gauge goes down?

96v6bird

I just gave you better answer. With it being slow I still shows to get around 225 miles. The gas gauges on these cars are bad about being inaccurate anyways. Answer is no, gas mileage is decent if you gotta get smart about it.

ninetyone

iTrader: (2)

whoa, i apologize. i wasnt trying to be a smart *** dude.

96v6bird

It's aight. I'm just gettin frustrated. It runs awesome 1 minute, scary tq and then the next doesn't wanna go anywhere.

Tired of fixing things and not fixing the problem. :/

ninetyone

iTrader: (2)

i see u have a maf car. no codes? did u change TPS? maybe a bad ecm.

96v6bird

I don't know. The ses light comes on and off at times but that's it. Replaced the tps with a new one. Maf is a reman from oriellys cause my old one was bad.

ninetyone

iTrader: (2)

ok then,maf is good,tps replaced,o2 replaced right? so lets move on, 1. what code is stored in your ecm?

96v6bird

I have replaced it but it did the same thing. Turned smokey white.

When the ses light did this before it wouldn't leave a code. Idk how to check either since I don't have a diagnostic reader for it.

ninetyone

iTrader: (2)

check your grounds behind your heads,are they all connected? what exactly is the car doing? or i should say,how is it acting. Be specific

ninetyone

iTrader: (2)

u dont need a reader,use a paperclip

ninetyone

iTrader: (2)

http://www.austinthirdgen.org/index.php?pid=27

bend a paperclip into a u shape,insert it into a and b at the same time.turn ign to "on" position. count engine light flashes. first 3 are gonna say 12

96v6bird

I think so.

The car at times either sputters/misses and before it warms up it acts like I'm not giving it any throttle until I give it more pedal.

Like I said, runs awesome 1 minute, terrible the next. It's weird.

ninetyone

iTrader: (2)

need to look for codes first, i mean u could have a bad injector,misadjusted tps, bad fuel pressure. gotta start with basics first tho. Did you set the tps correctly?

96v6bird

I replaced the tps like the other was in it. What is there to do with it to set it?

ninetyone

iTrader: (2)

https://www.thirdgen.org/tpimod2

that is how to set it,you may need to elongate the bolt holes in yours to make it more adjustable. its pretty easy. the 90-92 cars dont need adjustments tho.

ninetyone

iTrader: (2)

go check for codes man.post up what u find

96v6bird

Code 13 if I did it right. My Manual says o2 circuit. Sticking tps, poor electrical connection, open or short in circuit, bad o2 or bad ECM... Though the ses light hasn't always done this. Just so often.

ninetyone

iTrader: (2)

it should flash 12, 3 times,then it will show u codes .it flashes each code 3 times. code 13 is a bad connection from o2 sensor to ecm or low voltage at o2 sensor.that is probably not your problem tho.

96v6bird

Yeah that's what it did. Then flashed 13.

The fans came on when I triggered it.
Also when I went to start the car it wouldn't stay running unless I left my foot on the gas pedal. Didnt wanna idle.

ninetyone

iTrader: (2)

it wont run like that and fans should be on too.

ninetyone

iTrader: (2)

ok so, number 2. set tps

ninetyone

iTrader: (2)

u did change o2 sensor and still get a code 13? do u have headers? usually that code comes up when o2 is not getting hot enough. u can try to test the line from the ecm to the o2 sensor to verify voltage

ninetyone

iTrader: (2)

ok,this part u need a scanner or laptop for but anyway, splice into the tan wire (D7) at the ecm and take a piece of wire and ground it to the body. The o2 sensor's voltage should sweep. (across the voltage range) if this works , but no signal before then u have a bad ground.

ninetyone

iTrader: (2)

their is your ecm

ninetyone

iTrader: (2)

disconnecting neg. battery cable for a few will erase that code for u. then just start it up and see if its back

ninetyone

iTrader: (2)

you can use a multimeter to see o2 voltage too you know

96v6bird

I have stock manifolds. And this happened after replacing it.
Ugh this is enough to make me do a top end swap for a carb. Too
Much nonsense. :/

ninetyone

iTrader: (2)

nah,once u fix all of the old sensors youll' be fine. these are good engines,just 20 year old sensors. So all of this happened after u switched your manifolds,huh? hmmm.

96v6bird

No no. Guess I should explain..

Car was a roller. I got an engine complete with ECM from another 89 t/a and swapped it in. It's a mostly stock but complete low mileage engine. 98k miles.

ninetyone

iTrader: (2)

so your old engine was also an 89' tpi right? ok, what sensors are u using? the ones from the new motor? and the ecm is from the new motor too?

96v6bird

It didn't have anything but a harness and the rest of the car. But yes this is an original 350 car.

As far as sensors either they came with the engine or I had to get them.

ninetyone

iTrader: (2)

ok,so this has been going on since u put in new engine. where is the ecm that was in your car before? I would double check what ecm u have exactly and what chip is in it too. write down the numbers. u could have a mismatch somewhere

ninetyone

iTrader: (2)

http://www.youtube.com/watch?v=_g8PdrT0MCU

check injectors too

96v6bird

According to the seller it's an 89 computer with hypertech chip. Mild tube for exhaust and lower fan temp.

ninetyone

iTrader: (2)

well,find out for yourself. locate your ecm and get the part #s, same with that chip. So this car has been acting up since day1? what is a mild tube?

96v6bird

Well it ran great until I got it legal to drive. But since then yeah.. Temperamental ever since.