'95 Town car ABS light on and hesitation

[olopezm]

Hello guys, I've been working on this TC, it's the same that was sitting for one year, most of the problems are gone I'm only getting some hesitation after a cold start in the morning, it will last for about a second and will get back to normal for the rest of the day, could a low battery cause this?. And finally the ABS light came on, before taking it to diagnostic (I really hate mechanics, all I've tried do more harm than good) is there any way I can test the wheel sensors? resistance, voltage, etc.?

Thanks in advance for any help!

[olopezm]

I found some information saying I should measure resistance between both pins of the connector and there should be 800-1400 ohms, and after that measure between ground and each pin and there should be infinite resistance, is this correct?

Thanks!

[olopezm]

One quick update, today the car started to hiccup a little while waiting at a red light, could it be possible that the egr channels are getting clogged again or maybe I didn't clean them entirely?.

Also the car seems to shift a little bit rough on 1st-2nd gear and I believe it takes a little to go into overdrive when trying to overtake another car. Could this two be related or the shifting problems can be related to the shift lever having too much play, I still haven't found any info on how to re-adjust it.

Best regards

[olopezm]

So I never got any reply but here I am, I found the solution to both problems thanks to some research and another forum, here's the info in case anybody else has a similar problem.

ABS LIGHT:
I removed the air intake box, beneath there is the brake control module and it has a big gray connector with 28 pins on it, disconnected it and measured resistance between pins to make sure each wheel sensor is in a good condition, the expected reading should be between 800-1400 ohms anything different means a bad sensor. The measurements should be done as follows:
LF pin 5 & 6 T/O, T/BK
LR pin 9 &10 LG/R, LG/BK
RR pin 11 & 12 R/PK, PK/BK
RF pin 7 & 8 Y/R, Y/ BK


In my case all four sensors had a reading between 1090 and 1150 ohms, but the BCU connector had orange dust on it meaning water getting into it so I cleaned the contacts reassembled and tested, Now The ABS light stays off for sure. In case you don't get any reading at the BCU connector you'll have to trace each of the wheel sensors wiring harness and check each connector, somebody told me these connectors could go bad and would cause a broken circuit condition (high impedance due to the pins not making any contact at all).

About the hesitation the PCV valve was in a bad state causing some oil to go into the intake elbow and the rubber hose connected to the PCV had a crack on it. Replacing both things fixed the hesitation problems.

I hope this information is useful for somebody.

Best regards,

Oscar


EDIT: Nope forget about the hesitation, it's back I will have to keep looking for an answer on this, will update the first post as soon as I fix it.

[bunz]

Thanks for putting up the wheel sensor info. I had hesitation after cold start in my 93 Town Car. It turned out to be the mass airflow sensor. This is located right behind the air intake box and has a wire connector on it. If I remember correctly I found somewhere that you should test for certain voltage ranges on the connector while it was running to see if it was working properly. I did this and got all the right voltages, but decided to replace it anyway. It fixed the problem for about a year. When it came back I decided to try cleaning it instead of replacing it - worked like a charm.

They make cleaner specifically for MAF sensors, so you might try at least cleaning it (you want to spray the tiny wire in the middle of the sensor with the cleaner very well, but DONT touch it with anything else or you could break it).

Then if you can find the proper voltages, you might be able to test it for replacement.

[olopezm]

Originally Posted by bunz

Thanks for putting up the wheel sensor info. I had hesitation after cold start in my 93 Town Car. It turned out to be the mass airflow sensor. This is located right behind the air intake box and has a wire connector on it. If I remember correctly I found somewhere that you should test for certain voltage ranges on the connector while it was running to see if it was working properly. I did this and got all the right voltages, but decided to replace it anyway. It fixed the problem for about a year. When it came back I decided to try cleaning it instead of replacing it - worked like a charm.

They make cleaner specifically for MAF sensors, so you might try at least cleaning it (you want to spray the tiny wire in the middle of the sensor with the cleaner very well, but DONT touch it with anything else or you could break it).

Then if you can find the proper voltages, you might be able to test it for replacement.

Welcome to the forum bunz!

Thanks for the input, I totally forgot to update this thread, yeah I know what you mean about the MAF, I already cleaned it and the problem persisted, but I found out the spark plugs weren't properly gapped, I set them to the correct gap and works great know!

Best regards,

Oscar.