91 towncar trouble

I just picked up a towncar and its giving me trouble. it acts like its getting no fuel. I put in a new filter and flushed the fuel system but it made no difference. it will idle fine but has no power under load
where is the computer plug in on this car. thanks

Try cleaning the egr passages under that big air intake elbow on the intake manifold. They will fill up and clog with carbon over time. Do you mean the diagnostic port for the computer?

Do you mean the diagnostic port for the computer?

yes

Under the hood, drivers side. The loose connector by the power steering fluid box. It might still have the protective cap over it. It will be labeled. There is also one on the opposite side for the abs system.

Under the hood, drivers side. The loose connector by the power steering fluid box. It might still have the protective cap over it. It will be labeled. There is also one on the opposite side for the abs system.

thank you

is there an adapter that will make that diagnostic port work with an odb2 scanner I have an innova 3100

My scanner comes with a bunch of the different cables. It will scan obd1 and obd 2. I don't know if you can get just the adapter for yours, try contacting the manufacturer.

I got one of those $25 code readers from the auto parts store and the codes are 116 and 40
there is no code 40 in the book I have

I took it for a highway drive and it ran fine for a few miles then it just lost power and started chugging. I pulled over and the engine was barely running
when I pluged the code reader in it showed 6 cylinders but did not find any fault codes.
I turned the engine off and restarted it and it ran fine do I drobe about 1 mile and it started chugging again. I pulled over and done a diagnostic check and got the codes 136 172 and 176.
what I did notice was the engine runs fine with the code reader hooked up but as soon as I take it off the engine runs bad again. I got it home again and I hope some one can help me get this car going

some back ground on the car
its got 88600 on the odometer
it sat for 4 years in a garage before I got it.
it did 130 miles before this problem came up.
I flushed the fuel system and put on a new filter. I did not do the injectors. it has a new air filter
I have not done the spark plugs.

Hello,

136 means MAF or Oxygen Sensor not switching/system lean left or front HO2S - Fuel Control.
This code also appears when the Cats are going bad. Do you have a rotten egg smell from the exhaust?

172, and 176 means that HEGO sensor indicates lean bank 1 and 2.

Try this, clean the MAF, clean under the snorkel like Mike said on the back of the intake. and Check your wires going to the O2 Sensors under the car. Maybe a rat got to them or something. Sounds like when the car goes to Open loop is when your having the trouble. And the problem with it not going to Open Loop is... You guessed it, no power...

I was at the auto parts store and the guy there said it could be a weak fuel pump.he said that the injectors wont fire with out enough pressure.

I have the air box /plastic intake off and it was all clean. I am going to pull the spark plugs and have a look.

I have checked the wires from the 02 sensors and cleaned the MAF. I found some crud buildup on the red sensor in the airfilter box and cleaned it with brakeclean

What about the MAF? Did you clean it?

I cleaned everything and put it back together.
now I have no pressure at the fuel rail.
the fuel pump comes on when the key is turned and pumps up but there is nothing at the rail ....so ???

I took the filter out and turned on the key and the pump did not come on
I hooked up the code reader and it did its hardware test and the pump came on when it was tested.
so the pump works but its not getting asked to work. why?

Try swapping the fuel pump relay, it's on the drivers side inner fender that bank of 3 relays.

Try swapping the fuel pump relay, it's on the drivers side inner fender that bank of 3 relays.

tried that.
this ordeal is turning a good deal into a money pit

where is the PCM or the engine computer

Joe, I had a no start problem with my Town car a while back. The wires going to that relay bock Mike talked about, they get moved around over time. I had to start my car and wiggle that whole mess of wires to get it to start, and then it would shut off intermittently. Also, if you are not getting pressure to the rail with the filter on, There's got to be a clog in the line or the fuel pressure regulator. remember that the pump runs on pulse. You would have to cycle the key in order to keep it pumping. I would have someone try to start the car with the fuel filter off, and if you don't hear the pump coming on and staying on or see fuel, smack the bottom of the tank and see if that clears it up. Might be the bushings inside the pump. They get flat spots after time and use.

this is what happens with the pump. with the filter out so the gas goes on the ground I turn on the key I hear the pump but no gas comes out. I leave the key on and go to the test module/ code reader under the hood and turn it on and then press test it turns the pump on and gas gushed out onto the ground. with the key on I can take the 50 amp fuse out of the fuse box under the hood and every time I put it back in the pump runs but no gas comes out.

the local ford dealer told me itd the PCM but I can not locate the PCM. I have pulled the kick panels out from both sides and I looked it up on the internet and wiki said it was in the drivers door so I pulled the trim off and its no there

My wife has had enough of this car and I have only had it 3 days. it was supose to replace her suburban thats been giving us trouble. see my post in the suburban forum

thanks for the help so far

I hate to say it this way, but your wife and everyone else in this situation has to realize that the car sat for 4 years. That's a very bad thing. Problems are going to sprout up b/c of that. If the local ford guy said its the computer, then it might be. I would go the cheaper route and put a fuel pump in it to see if that clear it out. Sounds like the bushing that I spoke of have flat spots.. The pcm if I am not mistaken is on the drivers side behind the firewall, if you have your hood open, look to the right of the power booster, you should see a harness there with a 10 or 11 mm bolt holding it into place. You can access the PCM by removing the kick panel on the drivers sdie under the dash, and you will have to remoe the plastic trim that goes from the front doors to the back (very east screws hold it in) otherwise you will fight the trim to get into there. If you need a computer, I have access to 10 of these at my friends yard and I can get one cheap. I will need the VIN so I can get the right computer. Is yours a Sig? Exc? or Cartier?

Bryan

got a new carter fuel pump today. I will put it in friday morning and see what happens. the car is an executive with M in the vin

could it be the anti theft system stopping it from starting.
I only got 1 key with this car no remote or anything. the key is not original.
the anti theft light has never come on
do all town cars have anti theft or was it optional.

Yes the computer is up on the drivers side, next to the kick panel. You need to remove that black plastic trim under the dash to even see up in there. There is a 10 mm nut on the connector under the hood on the harness you need to remove. I doubt it's the computer, but if you need one I have several good 91's. That module in the drivers door doesn't apply to to the 91. That is the keyless the entry system and anti theft module on the newer models 95 and up. The only module you might have in your drivers door, would be the one touch down blue relay for the power windows, if you have that option. Your dealer guy is off by several years, and it's not even the right computer module. All pcm's are in the same location, drivers side kick panel 91 to 98 for the LTC. On the fuel pump it wouldn't hurt to change, at least you know there is a new one up in there. I don't drop the tanks on these cars, there is just enough room to pull the sending unit out if you have it jacked up high enough. The connectors are the bitch, you will need those special collar tools to remove the lines. I've had some that were so rusted that I couldn't get lines loose. That rusted one I pulled the sending unit out and changed the pump while siting under the car, then slid sending unit back in. You got to do what you got to do. Try the fuel pump and let us know if that fixes her.

the saga continues.
I put the new fuel pump in and now I have fuel pressure.
it wont start still. the injectors are not firing. I have spark at #1
I checked all the fuses and there is no error codes
what would stop the injectors from firing. there is no click.

it was running (poorly) the other day before I did the spark plugs. I had the air intake off and while it was running I sprayed brake clean into the intake to clean it. then I turned it off and did the plugs and it has not started since

I am wondering if he didn't hook up a vacuum line up.. Also thinking the fuel pressure regulator.

Joe, how do you know if the injectors are firing or not? Did you put the injector test kits on them? Also look at the harness that sits on the top of the intake (drivers side) and look at the harness. try to see if any mice got in there and are chewing up wires. Out of curiosity. Did you check all fuses and relays both under the hood and inside the car?

still no joy

today I put in a new
crank sensor
fuel pressure regulator
oil pressure switch
new spark plugs

so far I have also put in a new
fuel pump
fuel filter
air filter

I have flushed the fuel lines
drained the tank and put in fresh gas


after todays efforts I now have the injectors working but I think the spark is now not working. when I pulled the plugs they were all wet with gas.
I still get no codes on the reader. none of the parts I have replaced so far have been faulty except for the fuel pump which had holes in the rubber hose that connects the pump to the steel line and the fuel filter which needed replacing

I think I only have 1 more thing to replace. the PCM but I am not getting a code for it.

I did notice that the pump now runs while I am cranking . the pump come on when I turn the key to the run position and then after cranking it will come on a gain as the key comes back to the run position. if I crank for about 10 seconds the fuel pump will come on

I think the fuel pump is not working like it should. it seems to run too much. I took the wire off the oil pressure sender and the pump stills runs. thats not right

Joe, how do you know if the injectors are firing or not?
the spark plugs were dry when I took them out

Did you put the injector test kits on them? NO

Also look at the harness that sits on the top of the intake (drivers side) and look at the harness. try to see if any mice got in there and are chewing up wires. no mice in this car

Out of curiosity. Did you check all fuses and relays both under the hood and inside the car? yes several times




my answers in red.
thanks for the help so far. I am determined to get this nice car running. I got it from an estate and its a 1 owner and well maintained always garaged.
there is 1 other thing thats wrong. the radio hisses and keeps scanning for channels. if I put in a tape I can just hear the music in the hissing.




I am currently in north east Arkansas
so if you want to come for a visit I could use the help

If I was in the area, I would stop by and get it running for you. But I'm in Florida. If your not getting spark and you were before, I would double check the crank sensor PIG TAIL (PLUG) and be sure that it is in correctly and securely. On my 95, one of the wires on the pig tail got bent and was only attached by 1 thread of wire causing my problem. Also, check the plus going to the side of the coil packs and make sure they are intact and not corroded. If you would like to call me, send me a private message and I will give you my phone number.

Bryan

Yes you're right you should be able to hear the injectors snapping if they are working. I use a long screw driver and hold my ear to the handle. I know it's kind of a crude test, but you just can't buy every fancy tool out there. The spark issue could be the ignition module located on the drivers side fender. Check or replace that before you replace the ecu. Also check and see if the connector pins on the ecu are clean and not corroded. That's just one 10 mm nut to remove from under the hood, and easy to check.


This is starting to sound a lot like that one 96 that stumped me for last 2 years. This might sound off the subject. But check the compression on all 8 cylinders, just to humor me. I'm starting to see this one problem more and more on these 4.6L's. Check the compression and I will explain more. If the compression is good never mind , if it's strange on a few cylinders I know exactly what the problem is.

Please tell me either way. I am interested in knowing...

first of all I would like to thank 2 members of this board for their oustanding help. after reading all of this thread you know who they are.


today I put in a new coolant temperature sender because the old one was givin a fault code 116
I redid the wires to the crank position sender
then I turned the key and it started up. it ran rough for a while and was having trouble trying to idle. I took it for a drive and it seems to run good. I have turned it off and started it a few times now.

one annoying thing is the new carter fuel pump is loud. it sounds like a siren
it runs wurr wurr wurr with no stop. the original fuel pump was quiet. I had to realy listen to hear it in the car or take the gas cap off to hear it but then the gas tank was full. now its only on 1/4. I changed the oil sender and I am thinking of putting the original one back to see if its better for the pump

again thanks for the help

I'm happy to provide any knowledge or experience I have left to give. Great deal on getting the car running again. I've seen this on three 4.6 L engines now. The lifters will stick and the rocker arms will fly off. It happened on two that I own, and on a customers Limo.

just 1 more question
I have codes 136 and 176
what sensor are they refering too.

.I posted this already, but I pasted it below. These are your Oxygen Sensors. To be quite honest, I replaced all of mine at one time, and my car has run great since. They are a bit pricey though. Glad to help at any time...

Bryan


136 means MAF or Oxygen Sensor not switching/system lean left or front HO2S - Fuel Control.
This code also appears when the Cats are going bad. Do you have a rotten egg smell from the exhaust?

172, and 176 means that HEGO sensor indicates lean bank 1 and 2.