Codes Confusion

[Marccus]

Car is running hot.

water temp on dash close to high. Never runs this hot. needle always below middle of gauge.

Codes 81, 87

81 is IAS voltage problem and 87 is fuel pump problem.

I am continually having problems with these codes.

I replaced the IAS three times in the last year with new ones. The new one is about 6 months old.

I removed the inertia switch from the fuel pump circuit. the fuel pump is about three years old. I installed a new one (Federal Mogul I think).

I replaced the computer, the IRCM near the fan, checked the fusible link and circuit in the line that runs from the (+) battery cable at the battery.

In don't know what else to do.

The engine cooling system has been flushed and is clean.

I could check the thermostat as last time I looked the rubber ring started to separate from the thermostat housing,

I don't know what a hot running car would have with the codes or maybe it is just coincidental.

Any ideas?

 

[93rev2sev]

Unless you can tell us an actual TEMPERATURE, then there is no problem with your car.

"close to high" is useless information.

What you need to do is install a coolant temp guage. Then, you will KNOW if you are running too hot.

The IAS is the idle controller, so if you are not having problems with idle, ignore it.

I forget why you should ignore the fuel pump code, but ... again ... if the car runs, the fuel pump works...ignore the code.



Edit....In my experience, if a car runs normal for a long time and then starts to run hot, it's low on water or the water pump is weak.

 

[Marccus]

Coolant level is fine.

It has to be the water pump, original water pump with 410,000 miles on an '89 SHO.

The logic I was using about the temperature indicator, is that is the relative position of the indicator on the dial compared to where it has been over the last 19 years. So I believed that when the relative position changed dramatically, that would indicate a change in water temperature.

I do change the ECT sensor often and know what to expect if it "goes".

Also the engine compartment feels a lot hotter.

But your advice on the water pump is probably it.

I always assumed that the water pump quit all at once. In other words, there was no indication that it needs replacement, no symptom warnings.

I was obviously wrong.

Thanks for the diagnosis.

Also, I do have a gauge pod and all the fittings ready to install for an oil pressure gauge, water temperature gauge, and a voltage gauge.

But I was thinking, isn't it better to also measure the oil temperature and forget about the voltage.

Also, do you recommend mechanical or electronic gauges?

I've heard that mechanical gauges will always give accurate readings whereas the electronic sensors in the engine compartment are affected by the heat and vibration and eventually they "go" and you need to replace the sensor.

But then again, the mechanical sensors with their capillary tubing are very fragile and a pain to deal with

So I guess each has advantages and disadvantages.

 

[itwonder]

I think the problem is more likely to be a pressure leak and/or a bad radiator cap. Replace the cap with a Motorcraft one and pressure test the system. Replace the upper and lower radiator hoses. If the problem persists, I would replace that 19 year old radiator.

WP weak? The vane inside is stone simple, it either turns and pumps or it is broken. The only way it could be weak is if the vane slips on the shaft; is that possible with the SHO WP design?

 

[93rev2sev]

ITWonder is probably right.

swap the cap, then the hoses, then the radiator, then the pump.

WOW 400,000 miles?!@

 

[AREA 91]

410,000 miles on an '89 SHO.:woohoo:


That has to be the highest mileage SHO out there.

Even higher than Sdpatt!!!