New Eldo Owner: Speed Limiter Question

[Warmarshall2nd]

Well, I just got my first Cadillac- a '99 El Dorado. After driving for about 2 months, I've got it up to 70k mi.

Recently, I've started looking into getting more power out of the engine. I just built a cold air intake, which has given me great results. Now my concern, as I'm sure many other young drivers with a want for more speed, is how to overcome the speed limiter. I don't really have the money to have the PCM reprogrammed.

Is there any way to simply disable the limiter without totally pulling apart the engine, or am I going to have to be satisfied with a top speed of 110?

Sorry for asking such a naive question. Like I said, I'm new to this.

Thanks!

[AJxtcman]

I can do just the speed limiter.

[97EldoCoupe]

I thought the limiter was 112 MPH?! Anyways, AJ I still need you to do mine one day too and set it to the L37 /3.71:1 tune. I don't want to know your secrets but does it look promising reprogramming the whole PCM too, like setting timing and fuel trim, etc? I know if anyone can do it, you're the man.

[submariner409]

Warmarshall, Take a look at the stickers on the driver's door jamb. The letter after the stock tire size listing is the speed rating of those tires and therefore the setting of the limiter (which is an electronic function of the PCM, nothing else). S = 112, H = 130, and W/Z = 150+. Take a look at the sticker on the underside of the spare tire cover. All those codes are RPO (Regular Production Option) codes and give you what's in your car. There's a sticky at the top of one of these forums which leads you to the RPO code list link. (Look at the top of Cadillac Technical Tips)

Hope you retained the stock air box from the original cold air system: it supplied cooling air over the PCM (if the PCM was in the airbox). The original air intake was designed for your engine and removing it will do nothing except make more noise. Read up on the hundreds of threads in here and in Northstar Performance concerning the subject.

Resist the urge to throw money into hype and snake oil. Everything you want to know, every question about the car and engine is answered in here already. There are few and no worthwhile power modifications available for your car. Accept that: coils, wires, weird plugs.....no gains.

BTW.....Welcome Aboard !!!!!! Go up to User CP and update your profile and personal data with your car, year, mileage. It makes diagnosis easier if everyone knows what they're dealing with.

[Warmarshall2nd]

Thanks all for the input. I still have the airbox, yes, and am working on improving airflow for the PCM. It has given me some added power, I know that for a fact

Of course nothing good comes without a cost. My 'service engine soon' light is now on and the code is P0101. The MAF is in good, working order and there are no cracks/leaks in the system. As far as anyone is concerned that has looked at it, they believe that it's because the PCM isn't 'used' to having so much air.

Neither myself or other individuals have noticed any performance problems. I'm getting just as good gas mileage as before, and the tach is steady and the only error code i'm getting is P0101. I clear the error code, but it just comes back when the tach goes over 3000rpm.

Am I correct in assuming that the only way to be rid of the service light is to have the PCM tuned? If so, I think I can stand having a little extra light on the dashboard until I have the spare cash.

Again, thanks!

[submariner409]

Basically what you have done is change the air/fuel ratios at part and full throttle. The PCM will not "relearn" that imbalance. It may try to adjust long-term fuel trims, but that's a stretch. The code is set due to airflow imbalance at higher rpm. I can do the exact same thing with my JET MAF (which is on the shelf because I learned the hard way ($$$)) any day of the week. Many, many posts and pictures in this forum.

There's currently no one in business who can "tune" the PCM except AJ, and he's in the middle of working up a couple of other programs for a Deville and a later Shelby.

There's nothing like a set of before and after drag strip timeslips to substantiate your added power. Same day, same car, same fuel, different air intake systems. Anything else is a pipe dream......we've all been there.

[AJxtcman]

Originally Posted by 97EldoCoupe

I thought the limiter was 112 MPH?! Anyways, AJ I still need you to do mine one day too and set it to the L37 /3.71:1 tune. I don't want to know your secrets but does it look promising reprogramming the whole PCM too, like setting timing and fuel trim, etc? I know if anyone can do it, you're the man.

S = 0053005A = .S.Z

H = 80618068 = .a.h

Q = 8045804C

Oh no Sub didn't list the Q rated tires

[Joenichols_1]

I got a z rated eldo a 1997 is there any performance mods for it i got a different intake onit i would like something else im planning on doing exhaust with flowmaster 40's and and a bigger Y pipe leaving the stock tips anything else i can do to get more juic out of the beast

[submariner409]

Read the entire Northstar performance threads and the Cadillac Technical Tips at the top of the page in the black bar.

In a word: "NO".

[Warmarshall2nd]

Nothing really pre-made. Good luck with that CAI. When I first did mine I wasn't very smart about it and lost a bit of performance. So at first, it only sounded/looked better.

Now that I've made a few more adjustments and fabrications, it's working just fine.

If you want to do work to it, you're going to need to do a lot of research and make build your stuff yourself.

[Joenichols_1]

well i know how to machine parts and have access to a cnc machine so maybe what all have u done to urs and what did u do to ur CAI mine morks fine the engine light came on when we first hooked it uo then it went off never had a problem since and it sounds louder, looks cooler runs faster

[chubbyranger]

Originally Posted by Warmarshall2nd

My 'service engine soon' light is now on and the code is P0101. The MAF is in good, working order and there are no cracks/leaks in the system. As far as anyone is concerned that has looked at it, they believe that it's because the PCM isn't 'used' to having so much air.

From FSM on P101:

An improperly installed air cleaner or distorted/missing Intake Air Duct may cause this DTC to set.

Translation: your CAI setup is pissing off the MAF.

[submariner409]

Joenichols_1, Your CNC machine is useless for air intake modification for a FWD Northstar. ("CNC" is now almost the same buzzword as "billet" was 15 years ago.) Read the threads, learn the tricks, and work toward meaningful performance gains......not just check engine lights, "look what I got" and noise.

Toyotas with spoilers and fart cans make noise and bling. That doesn't cut it here........

Runs faster ????? Please post your before and after drag strip time sheets.

Have you ever done any MAF modification work ??? Look at the pic and the differences between the left and right 2002 MAF's. The left is more open, less restriction, faster, right ? WRONG !! Slower, worse gas mileage, and "Check Engine" light (but noisier). The OEM is happily back in (08-15-07) and just fine, Thank you.

[Warmarshall2nd]

Originally Posted by chubbyranger

From FSM on P101:

An improperly installed air cleaner or distorted/missing Intake Air Duct may cause this DTC to set.

Translation: your CAI setup is pissing off the MAF.

Yes indeed it was. It also caused my car to stall because the MAF sensor was causing the PCM to adjust intake. At low rpms it stalled my car lol

But it has been taken care of. Old news lol

[burnsrobert]

i did 125 in my 1998 eldo was fun and fast i think it had more but i let out of it