Cadillac Owners Forum banner

1 - 20 of 20 Posts

·
Registered
1993 STS, 1997 STS, 2002 SLS, 2007 CTS 3.6
Joined
·
378 Posts
Discussion Starter #1
Hello all, new to this board and really like what I have seen so far. :)

I just aquired a 93 STS with 111,500 (traded it even up for a 1990 4 runner, I think I did good.

Unfortunatly the STS has some issues, which I knew going into it.

There is a major hestitation problem, feel like fuel related but cant be sure. I know just enough about cars to make me dangerous. hehehe

When accelerating it hesitates like it is running out of gas. I have been told that it could be a bunch of things. Fuel filter, plugs & wires, Dirty/bad injector....just kinda looking for a starting point on what to do first if anyone has any ideas.

My mechanic said he thinks the plugs and wires are original (groan).

The other issue is fairly odd but must be common since my 86 Deville did it as well.

The fan for the heat/air will stay on even after engine is shut down. My Deville had this issue so I would just unplug the motor and plug it back in when needed. All of a sudden it stopped doing it and hasnt done it in 6 months...very odd.

I know GM doesnt have the greatest reputaion for there wiring, I am just wondering if anyone else has had this problem or any ideas where to start, sensor of some sort, a module, wiring?

I have run fuel injector cleaner though 1 tank of gas with no improvement (didnt think it would but what the hey). Have only had the car for about a week. Also today it started to die out while at a light RMPS when from 800 down to about 400 and than back up maybe 3 times in about 60 secs.

Any ideas suggestion would be greatly appreciated and I look forward to being around for as long as you'll have me :)
 

·
Registered
2005 CTS-V, 1994 Infiniti Q45
Joined
·
7,658 Posts
First, welcome aboard!!! And we will have you as long as you stay :) ....... Make yourself at home :wave:

Those fuel injector cleaners are a waste of money, the only ones i would consider using are the chevron TECHRON stuff, or BG44k......

According to GM, the plugs and wires SHOULD last the life of the car...... Maybe not the wires, but the plugs CAN......

Basically, I am going to run down the list of things to check for in my Q45 service manual (something like this most cars should be the same)

sparkplugs- fouling/excess fuel
o2 sensors
vacuum lines/air leak
injectors
ignition spark
fuel pressure

Along with that, I would check the fuel filter, air filter, etc.... it may not be the cause of the problem, but it wouldnt be a bad idea to check anyway!! I would start out with a visual inspection of the vacuum lines, then start replacing things..... A pressurized injector flush may not be a bad idea (80 maybe at an independent shops, they clean out the injectors REALLY good)

As far as the fan, I dont know, you may want to post a seperate thread in the electrical section!!
 

·
Registered
Joined
·
6,471 Posts
The best thing to do is "assume" that the car has had NOTHING done to it. Do a "COMPLETE" tune-up:
1. Plugs
2. Wires
3. Air filter
4. Fuel filter
5. Clean the Throttle Body and IAC passages
6. Check for computer fault codes

From there, I would check the following:

1. Timing chain slack
2. Compression
3. Fuel pressure
4. Check injector balance
5. EGR system

Unfortunately, most of this stuff will require a good, honest mechanic, sorry.
 

·
Registered
2005 CTS-V, 1994 Infiniti Q45
Joined
·
7,658 Posts
Listen to this guy, he knows his stuff!!!
 

·
Registered
1993 STS, 1997 STS, 2002 SLS, 2007 CTS 3.6
Joined
·
378 Posts
Discussion Starter #5
Thanks for the tips guys. I am still scouting out for a mechanic I can trust. I changed out the air filter last night (OMG was it FUNKY!!) and PCV valve andthere is "some" improvement to the hesitation.

One more question is it safe to buy store parts from a regular auto parts store or do I need to pay triple for the stuff from the Dealer?

Thanks again...

Rick
 

·
Registered
2005 CTS-V, 1994 Infiniti Q45
Joined
·
7,658 Posts
Some things will be OK to buy from autoparts stores, but anything big should come from the dealer.....

Parts like filters, thermostats, batteries, etc are fine from parts stores, but things like electronic components should be bought from dealers...... If you are unsure, you can ask us.......
 

·
Registered
Joined
·
174 Posts
Realtor1 said:
The other issue is fairly odd but must be common since my 86 Deville did it as well.

The fan for the heat/air will stay on even after engine is shut down. My Deville had this issue so I would just unplug the motor and plug it back in when needed. All of a sudden it stopped doing it and hasnt done it in 6 months...very odd.

I know GM doesnt have the greatest reputaion for there wiring, I am just wondering if anyone else has had this problem or any ideas where to start, sensor of some sort, a module, wiring?

QUOTE]

I believe this is the Blower Control Module which should be mounted in the top of the blower motor housing. It has 2 plug connectors, and 3 small screws holding it in. This is a classic symtom of this part failing from what I now know. Have the trouble shooting guide and schematic for this too from the GM service manual.

I have a 93 Eldo that the blower motor just went out on. I bought this part used first thinking it was the problem. If you want this part we could verify that they interchange, I'd give it to you for $15. Believe me, it's a lot easier fix than that blower motor replacement! :hammer: Email me at [email protected] if you're interested. Can send part no. and pic of it.

Good luck with your other issues, once you get them ironed out you have a great car! :cool:

Dave
 

·
Registered
2001 DTS, 2005 Mustang GT, 2010 MINI S
Joined
·
1,121 Posts
northstar.......

Could simply need a tune up. Also Northstars are sensitive to clean fuel filters. Something to check.

As for the blower its a blower module failure. Classic blower module failure is 'fan runs all the time'.

Logan
 

·
Registered
1993 STS, 1997 STS, 2002 SLS, 2007 CTS 3.6
Joined
·
378 Posts
Discussion Starter #9
Thanks to everyone for the input, its greatly appreciated.

So far I have fixed
oil Leak (oil sending unit)
New Fuel Filter
New PCV Valve
Injectors cleaned
Found and repaired a vacum leak

Getting ready this weekend to do the plug wires etc.

After doing what I have done the hesitation is still there but it is better car doesnt really buck hard anymore just surges a bit but still very noticeable.

Make matters better now have a pretty good leak on the radiator...Groan

One last question, I have a really funny feeling the last owner(s) probably ran the cheap gas through could that have something to do with the hesitation? I am stick with the premium *ouch* 30.00 to F/U...

Thanks again guys

Rick
 

·
Registered
1993 STS, 1997 STS, 2002 SLS, 2007 CTS 3.6
Joined
·
378 Posts
Discussion Starter #11
Just a quick update, I changed the brakes last night after my mechanic saying 586.00 for the job. Anyway, now all of a sudden my fan blower does not stay on, yes, I know the brakes have nothing to do with the blower.

Has anyone ever had the problem just fix itself other than Stephen King and Christine :bonkers:

My 86 Deville had the same issue and than "fixed" itself as well..very odd.

I am going to buy the extra module Dave has if it matches up just incase this fix is temporary (which I believe it is)

Anyone who has seen this before let me know so I dont think I am insane or have some special car healing power...hehehehe
 

·
Registered
1993 STS, 1997 STS, 2002 SLS, 2007 CTS 3.6
Joined
·
378 Posts
Discussion Starter #13
BUILDINGCTSAMG said:
Back to the hesitation problem, go buy a bottle oF bg44k its great stuff (about $20 a can) and really helps!
Think its still worth doing even after the injectors have been cleaned?
 

·
Registered
2005 CTS-V, 1994 Infiniti Q45
Joined
·
7,658 Posts
How were the injectors cleaned???

BG44k wont clean dirty injectors (it will to some degree, but wont replace an injector cleaning), but will keep clean injectors clean!!! I would use a can at every oil change (mixed with 1/2 tank of gas)......
 

·
Registered
1993 STS, 1997 STS, 2002 SLS, 2007 CTS 3.6
Joined
·
378 Posts
Discussion Starter #15
Realtor1 said:
Think its still worth doing even after the injectors have been cleaned?
Also where do you find it I went to Auto Zone and 2 other parts places and they havent even heard of it.

Thanks
 

·
Registered
2005 CTS-V, 1994 Infiniti Q45
Joined
·
7,658 Posts
You cant get BG44k anywhere....... You can only order from certain BG dealers..... You can go to www.infinitipartsusa.com and buy it there!! I just ordered a bunch of parts from them......
 

·
Registered
Joined
·
1 Posts
I had the same problem. It was the coil pack module. The Mod sits under the coil paks. This park is not cheap but cured problem instantly!!!!!!!!!
 
1 - 20 of 20 Posts
Top