I been dealing with a code 44 but first you should know Is what is replaced. I replaced the fuel pump,fuel filter,MAP sensor because it was throwing a code for that and that's fine now, spark plugs ,o2 sensors on both sides and checked the wiring and they don't look burnt or melted or anything. Also cleaned the Maf sensor. A fuel injector on the passenger side was leaking and I put new o rings and the drivers side fuel rail was loose to where I can move it a little bit so I tightened it back down and is good now. Car starts right up and is fine at first but the cooling fans come on a little too early , around 150°-160°. And as soon as they go on the service engine light come on and I check the codes and it's still there code 44. H44 so I know it's a history code but I cleared it at least 2 times and it comes back. Car has 220,xxx miles. What could it be? Any help is appreciated

 

well - how about exhaust leak? vacuum leak? You've replaced a multitude of parts and I'd say that miles and the parts you've replaced might hint the need for a "scan by a capable device" and try to confirm the issues. Have you confirmed that the O2 connector is good and that it's actually connected.

The coincidental cooling fan operation with the miles/age - do you know that the temp is accurate? Is it from the DASH/CLUSTER (analog) or from the DIGITAL display?

 

I checked the o2 sensor wiring physically and it is connected and looks good but if the wire was open or burnt anywhere wouldn't it throw the other code where it's say it's open or not grounded or something? Also I replaced both the analog temp sensor and the one for the computer (digital) the other day so. As for exhaust and vacuum I'm gonna go and check thoroughly. As for vacuum leaks, where should I look? I replaced a couple hoses that were brittle and just had to go that were by the map sensor. Thanks for the reply

 

Did you buy all of your parts local? Where and brand of O2's and maybe with the cooling fan issue I'd just do the CTS in the pump. Maybe the connector also - you mention "just doing" so that's where you've been last ... Bad new part? Maybe! Connector? Lots to diagnose for you .. You're located where?

The miles make it very difficult to "suggest" - short of a scan by someone that understands.

 

Parts I got all local from local parts store and the brand of the o2 sensors are Bosch I believe . I was thinking that maybe it's just bad also because if it's new it doesn't mean it's not broken possibly. So I think I'm gonna swap the o2 sensors and see what happens. And what do you mean with the fans ? Cts? And Im in Arizona by the way

 

CTS - Coolant Temp Sensor / ECT - Electronic Temp Sensor

I'm accustom to mentioning "the where" and for the ECM it's in the pump so .. The fans are controlled by the ECM for '93, you've
replaced the CTS not mentioning issues previously but NOW you've fan issues maybe.

 

The problem was still happening before and therefore I replaced the temp sensor by the water pump because that's the one the computer uses and the one for the dash was broken so I replaced that also just for hell of it.

 

I rethought this a bit and on an LT I'm quite sure that as soon as the ECM see any code the cooling fans are turned on SO maybe assume your CTS etc are OK. The CODE 44 is triggering the fans.

Maybe "'93Rubie" will slip on by later and offer up something BUT miles are certainly not on your side. Does the cruise and the AC work as you would expect with NO issues that might indicate a vacuum failure?

 

Ya I'm thinking possibly it's reading the o2 sensor code when it gets warm and then turns on the fans as a precaution . AC works but weird thing is that it blows out the bottom and not the top at first. After a little it will slowly blow out the top vents and then finally just blow normally. Cruise works fine in the car.

 

I was going to edit my earlier post but since you've revisited I'll just do new.

When the fan turns on which is it?

Do you have FSM - Factory Service Manual? You've spent a good bit of money for parts and I'm only curious as to what you're using for references.

 

My 94 the fans come on at 228 and 238 could have someone reprogrammed them? I would get a cheap cigar and blow in your vacuum lines looking for a leak. I would start with the line to the brake booster.
might also use a unlit propane torch when running around the manifold.

 

No manual just what people have been through on here on corvette forum . And I'm assuming it must turn on the radiator fan not the AC fan. But l never looked to be absolutely sure. And most the stuff I got for it it needed such as fuel pump,fuel filter, and water pump as well.

 

Code 44 for a 93

This indicates the left O2 sensor is lean and the voltage is not varying as normal and remains under 200mv. It will light up the MIL lamp and the engine will go into open loop. I would not be surprised if it turned the radiator fans on also for safety. I would check the O2 swings as my first step.

A scanner would be a great help to verify that this is the problem that is happening. Long term trim needs to be checked to see if the trim is a high number. If using a Tech1 where a scale of 128 is perfect, if the LT trim is high 160+ , that would be a lean condition. If using another scanner where "0" is perfect LT trim, a high number would indicate a lean condition.

Make sure the pin connections are good and no wires are broken. Melted wire insulation can cause a short also. I just replaced a O2connector cause this happened to me (23 years old and all that heat).

If all connectors look good, possibly the O2 has gone defective.

A scanner and not a code reader is needed for this effort or you will be working in the dark and taking pot shots.

Most people use Denso O2 sensors. I had to buy a Bosh O2 for a test sensor as I was troubleshooting a problem and it did work however it's not recommended to use for the C4s from what I have read.

 

Check which fan it actually is to "confirm" the FSM statement. I believe it will be the secondary (right hand). I used a '92 FSM because it was closest and '93 I'm somewhat confident should be the same.

Your check since we know it's ECM fault triggered would confirm.

 

Ok first off Code 44 is LEAN Exhaust Indicated-could be a LOT of things.

Why did you replace the fuel filter/pump? Did you test it? What was the pressure?

You replaced the MAP for a code. Code has not come back. Did you confirm proper readings? You CAN do this with a multimeter.

How did you check the 02 wiring? Visual inspection only?

1993's do not have a MAF, what did you clean?

How do you know the injector was leaking?

Considering 1993's had Multec 1 injectors and you have 220,000miles on your car. If I had to take a WAG, you have one or MORE shorted out injectors.

Ohm test them with a multi-meter. Its not the best test but its a $7 test from your local Harbor Freight. Suspect ANYTHING under 11ohms across the injector terminals. I don't care what the FSM says about above 10ohms. I had one failing on a CLEAR current ramp pattern and it Ohm'ed at 11ohms.

Do you have any means to view scan tool data? 1320electronics sells a nice piece for less than $100.

What is your idle speed on a warmed up engine? If you have ANY vacuum leaks it will likely be high.

 

Sorry for not replying for a long time. I rebuilt the engine and never figured out why i had the lean condition but i did find that on the cam, some lobes were really worn down. All good and running and driving it daily withh no codes. Thanks for the replys.

 

Better a late reply than nothing at all. Glad it is fixed!