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Am I getting taken advantage of?

9

94xjstud

NAXJA Forum User
Location
San Jose Ca
My car was sputtering and dying, so I took some advice, changed the fuel filter and checked the pressure at the rail. There was no change. I took it to a mechanic the result is so far that I needed a new cranksensor, which I expected, a new battery because It was not holding a charge. The reason the battery was bad is because the computer had gotten mud and water in it and was telling the alternator to send to much power to the battery thus overcharging and ruining it. The computer could also be what messed up the crank sensor. A new computer is going to run me over 500 bucks. Am I getting pushed around the block or is this legitamit
 
Re: Am I getting F'ed in the A

Computers for your year Jeep on Ebay for $50...

http://search.ebay.com/search/search.dll?from=R40&_trksid=m37&satitle=94+Jeep+Ecm+Ecu&category0=

Worse than that, I doubt that your computer is bad...If it is bad, you can change it yourself pretty easily...Crank sensor, probably bad, not the easiest part to replace..

Battery...you can change that yourself...if you buy a battery at Autozone, they will install it for you...

If I were you, I would have them change the crank sensor and then RUN!!!!
 
Re: Am I getting F'ed in the A

I agree with McQue. Test battery/crank sensor and replace as necessary. Definitely wait on the PCM and in the event that you do need one, head to a salvage yard or check ebay. One thing at a time. Good luck.
 
Re: Am I getting F'ed in the A

If the battery is bad enough, it will run like crap because the chrysler electronics are sensitive to voltage and noise, which are stabilized by the battery. A battery that doesn't take a charge correctly will actually give you overvoltage when running, as well as staticky, high-frequency chopped DC. Get a new battery first if the old one is bad, and don't replace anything else until you've done that.

Once you have a good battery, get a cheap multimeter, (which is something you should own anyway, and at ten bucks or less these days there's no excuse for not having one!:lecture:) and test voltage at the battery before thinking about new computers and such.

I would also doubt the crank sensor unless it failed to start, but if you have to let the garage do something, you might as well let them burn you for this, since it's kind of a nuisance to do and a new one won't do you any harm. Keep the old one as a spare.
 
Re: Am I getting F'ed in the A

carnuck said:
Rewire the alt to an external regulator (commonly done on Dodge trucks)
Click to expand...
Do you have any idea which regulator they are using?
 
Likely the common '68 Dodge pickup (simple keyed power in and field power out) or '73/later electronic version.
 
So I just picked my xj up. He replaced the CPS and a battery(no labor charge for the battery) but he told me that my check engine light was on. Well when I brought it in it was not on and when I picked it up it wasn't on :huh:. He said the computer needed to be changed off of what the diagnostic said. but he ran the diagnosic because the "check engine light was on" so I don't think I am going back there.
 
Ok...time to get a meter on the battery...get a voltage reading with the motor off, and another reading with the motor running, with the headlights on, radio on, and blower for the heater running on high...post up and let us know what you find for those two voltage readings...

By the way... how is it starting up, and how is it running as compared to before you brought it in to the shop?
 
Many problems, including those induced by a bad battery or connection, will throw odd codes, including a bad computer. Don't replace the computer until you've cleared the codes, fixed the known problems, made sure all the connections are good, and lived with it a while. If you got mud and junk on the computer, make sure the connector is clean and dry. I had problems on my 95 in high rains because moisture would get into the bottom of the lowest connector. It would kill the tachometer intermittently.
 
The cps that he changed was definetly damaged. It was hitting some part of the engine and melted part of the wires. It runs great now. has not died and starts well. I'll need a day probly to get the voltage stuff. I can only do this with the new battery, I don't have the old one.
 
Kind of common on these to have the CPS harness hit the exhaust and melt the wires, especially if some work has been done in that area. If its running great I kind of doubt that PCM is bad.
Do as suggested and get a voltmeter and check the voltage. Out of curiousity, what did he charge you to replace the CPS.
 
I'm not as familiar with the Jeeps, but if my mechanic told me my computer had messed up my alternator, I would walk out and not come back. The voltage regulator is what controls the voltage going to the battery, and it's in the alternator on the cars I've worked on.
 
markwsoil said:
I'm not as familiar with the Jeeps, but if my mechanic told me my computer had messed up my alternator, I would walk out and not come back. The voltage regulator is what controls the voltage going to the battery, and it's in the alternator on the cars I've worked on.
Click to expand...

Than you would be wrong, On a 94, which the OP has, the alternator gets it's field winding signal from the PCM.
 
Thanks for all the input. I am going to check the voltage. For the diagnosis, battery, CPS, labor, taking the computer on and off, and just a general glace at everything was like 450. I should have just gone with my gut and changed the sensor myself. It would have been a pain( I hear) but it would have saved me some precious money.
 
94xjstud said:
So I just picked my xj up. He replaced the CPS and a battery(no labor charge for the battery) but he told me that my check engine light was on. Well when I brought it in it was not on and when I picked it up it wasn't on :huh:. He said the computer needed to be changed off of what the diagnostic said. but he ran the diagnosic because the "check engine light was on" so I don't think I am going back there.
Click to expand...

I'm assuming it's a '94 your talking about... any chance that was a code 12 he got when he started the jeep? I get a code 12 everytime I do any work to my jeep where the battery gets disconnected. The code clears itself once it's displayed... you won't see it on the next start up.

Alway's some joker trying to rip off the public...
--
Jeremy89XJ
 
Well, that I'm unsure of... I'm not one of the 'experts'...
I was saying that a check engine light with a code 12 after having the battery disconnected is common.
If your mechanic saw the check engine light on when he started it, and you didn't see it, then it may have been simply code 12. If he was trying to rip you off, and didn't want to see money walk out of the shop, then telling you the check engine light was on and it was some terrible code, may get you to second guess yourself and purchase that new computer.
If the rig is running normally now and not throwing anymore codes at you, why worry?
If it's still running like piss, then listen to what the experts here are suggesting you do and good luck. They have helped me through all sorts of XJ issues, weather they knew it or not. IMO, NAXJA is far better than any shop manual printed!
--
Jeremy89XJ
 
I've also had the light come on once or twice after replacing a component. I don't know why, but it can take a couple of starts before they clear. It also takes about 40 starts before stored codes clear, so if you have any doubts, you can read the codes yourself. The OBDI system is easy to read. Just cycle the ignition ON-OFF-ON-OFF-ON and then leave it on. The check engine light will blink the codes. Every code is a two digit series of blinks. "5-5" is the end of sequence, and always comes up. "1-2" means the battery has been disconnected at some point. All others mean something else. You can post any code you pull here and someone can check the factory manual, but most are also correct on this website: http://www.allpar.com/fix/80s-codes.html

It's also important to remember that a fault in one key component can often trigger codes in others when things start running badly. For example, when my cam position sensor went out, it first threw just that code, but after a couple of forced starts with a bad sensor, it also threw a crank sensor code which was not true.
 
markwsoil said:
I'm not as familiar with the Jeeps, but if my mechanic told me my computer had messed up my alternator, I would walk out and not come back. The voltage regulator is what controls the voltage going to the battery, and it's in the alternator on the cars I've worked on.
Click to expand...
Chrysler/Jeep had the weird idea...sooner than most (mid 80's on some Mopars) to put the PCM/ECM in charge of that...they had some poor and mixed results...but since then most car manufactures have done it
 
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