Low coolant light! HELP!!!

[Bad89coupe]

Hi folks! New to the forum , but I do have a couple of questions I am hoping someone here can help me with. I own a 1989 coupe, auto and recently have had the low coolant light come on. I have had the coolant switch and the coolant sensor replaced to no avail. We bled the system of air bubbles and when I took a trip this past weekend it went on again and stayed on at highway speeds. Whn I stopped or was doing city driving the light did not come on until I was back on the highway and then again there it was! What can I do to correct this?
Also, lately I have been having hard starts in the morning, not when it is warmed up but first thing it takes longer than usual Mass air flow sensors? burn off and burn off control? Any help with this, especially the coolant thing will be greatly appreciated. Thank you all in advance!

Betty

 

[RedRagTop]

Hey and welcome to
The most common cause for a false low coolant is air trapped in the system, so maybe there is still some in there. My manual discusses this and you can do a search at the top to find threads on this subject.
If you have a MAF or sensor problem it should show up as a Service engine soon code. Likely you need an overall tune-up.
I find if I turn my key on to acc while I buckle up then start it reduces my crank time.

 

[c4ever]

I would check fuel delivery for hard cold start. Pressure test, regulator and injector performance.

Carlo

 

[Magmotor]

I'm not too clear on what you mean by "coolant switch"?? There is the Low Level Sensor..on the radiator and the Low Coolant module....located in the dash, pasenger side...is that what you had replaced??

If both are new then you have an "Open" wire---the green one--from the sensor back...or the black one...from the module....

I have a step by step procedure that will trouble shoot the "Low Level Light" always on. It will definetly pin point your problem...It is too big to put on this forum but if you like, you can pm me and I can send it to you thru e-mail....

 

[Bad89coupe]

Yes the low level sensor is what I meant and the coolant sensor as well. What words do I put in the search for this problem and other threads to this to see what else I can do? As far as the hard start, I do wait for the acc bell to go off before I start her in the morning, but it still takes a bit to crank unless it is warm. We did a fuel pressure test and it holds at about 40psi. It has 35,000 miles and is driven daily maybe a fuel injector cleansing? Oh and thanks again and thanks for the welcome!

Betty

 

[PsychoVetteOwner]

I had this exact issue as well
The solution was simple. Change your radiator cap.

 

[Bad89coupe]

Okay well thank all of you for your input. Since I did change both of the coolant parts, the next step is to drain the radiator, remove it, power flush and clean, then reinstall. I will get a thermostat and a cap as well (wouldn't hurt) and take the steps one at a time. Hopefully cleaning the gunk out of the radiator will make it run a bit cooler as well.
As far as the hard start goes, I am going to have the injectors looked at tested and cleaned while I am at it. maybe once and for all this will cure all of the baby's ills.

 

[hawaii-5-lo]

hey there,
i had an a 89 also,it was tricky to fill and get the bubbles out especially if your not familiar with vettes,the coolant fill is below the top of the radiator and intake.there is a "tee" on the passenger side rear of the intake,kinda by the EGR tube.i used to bleed the air out at that point were the rubber hose meets the steel hose.the steel part goes to the rear of the intake manifold if i remeber.its been a couple years since i owned it.thats the highest point in the cooling system.my light went of after i fiqured that out.good luck.Todd.

 

[blackvette89]

I HAD SAME PROBLEM WITH HARD STARTS ONLY WHEN COLD! IT ONLY GETS WORSE. IF YOUR INJECTORS ARE PULSING AT INITIAL CRANK AND YOUR FUEL PRESSURE IS GOOD. YOUR TURNING KEY AND ALLOWING FUEL PUMP TO TURN OFF BEFORE CRANKING AND YOU HAVE NO SERVICE LIGHTS COMING ON OR CODES TO TROUBLE SHOOT, TRY THE ECM THUS WAS MY PROBLEM AFTER REPLACING MUCH UNNEEDED PARTS. GOOD LUCK!!

 

[hawaii-5-lo]

hello again,
as far as your hard starting,the first two things to trouble shoot should be the fuel filter,has it been changed since you owned the car?and the fuel pressure.either one of these would cause extra cranking to get the fuel to the rails,during long sitting,the pressure will bleed off the rails.good luck,Todd.

 

[Bad89coupe]

Thanks again for some of the great advise. The car does start hard when cold, but it is driven daily. therefore it wouldn't lose pressure from sitting. Like I said, the start is good when the car is warm but it does take a bit to crank forst thing in the morning. I have not changed the fuel filter since we have owned the car, so I will look into that, also a good injector cleaning, professionally of course, not that gas additive stuff which never seems to work anyway. The pressure test was at about 40 psi at start up, I don't know if this is the norm. Someone said something about the ECM? What is that and where do I find and test it? Thanks.

 

[Utah]

Bad89,

I am having this same problem with my 89 and the low coolant light. I am new to vets so I havnt found the problem yet.... Let me know what solves your problem in th end.

Utah

 

[blackvette89]

the ecm is the engine control moule. the cars computer chip! its around $80-200 depending on where you buy it. you have to save what is called the prom from your old one. this allows for new computer to deliver same perfomance. it is located under the dash. my ecm showed no trouble codes when looked at by service station. but after replacement, i've had no issues. i had replaced the iac, fuel filter and fuel pump. all relays known to man! this ecm could be your problem. there are other possibilities like knock sensors and iac issues but for the headache i'd try the ecm. its the easiest!

 

[hawaii-5-lo]

hello again,
when i let my 89 sit over night the presure would bleed off.thats why when you turn the key on the pump goes on for 2 seconds to pressurize the rails.my problem turned out to be the fuel filter was severly plugged.
coolant-try this ,with car cold remove radiator cap,fill,start car(with cap removed)when t-stat opens,radiator level will drop or bubble,reinstall cap,fill plastic reservoir to full.drive car.the book says you may have to do this up to 5 times to get the air out.
good luck,Todd.