Bad gas I hope...

[Motorhead350]

Just got my car dyno tuned last night and over all it's making about 465 to the crank or so they say. My cats are clogged and I know some of you now hate me for never replacing them after my kerosene meeting last year. Now I know I need to change my cats or get rid of them all together... I know we need 2 for back pressure so I'll get rid of all of them and put in 2 new ones. The car is a lot better of the line, but in the top end it seems to rev and not shift for a second plus the car isn't shifting as fast anymore, but BigDogJim said my shifting was too hard anyway.

Now here lays the problem: When I start the car is idols to 2,000 and when put it into gear it'll go down to 1,100. Sometimes it'll even die when it goes down too low while in drive. In netural it'll idol to 2,200, go back and forth on the rpm and eventually drop dead in 30 seconds. All of this happened after I put additional gas in the car which was 92 not 93. I put in half a tank and will put in a full tank of 93 today along with octane boost just to be sure.

Could bad gas be the problem or did these people screw up my tune? :confused:

[fastblackmerc]

First how do they know you have 465hp to the crank? Did they take the engine out and dyno it on an engine dyno? If they left the engine in then the only valid hp number would be at the rear wheels. Anything else is a WAG (Wild A$$ Guess).

Second, the cats, although do provide back pressure the engine doesn't need them.... they are only for emissions control. Replace the four stock cats with 2 hi-flow cats. That will keep the computer and the enviromant happy.

Third, the octane in the gas has nothing to do with the way a car idles. You have a bad or dirty sensor or the tune is messed up.

[KillJoy]

Your tune is junk.

Did the Dyno person dyno tune the car?

If not...congrats on tossing your $$$ away.

:up:

KillJoy

[RF Overlord]

Dom, if the car didn't do this before yesterday, then check to be sure nothing got disconnected under the hood while the tuner was under there...like the MAF, or a vacuum line. Also, could be the IAC has gone south.

Your car won't notice the difference between 92 and 93 octane except under WOT. Don't bother using octane boost, either...it doesn't do jack.

[1of327]

Sound like either a bad tune or a sensor is not connected/ bad

[racorcey]

Just got my car dyno tuned last night and over all it's making about 465 to the crank or so they say.

What kind of corrected figures did they give you? Was the TC locked and were you in 3rd gear when they dynoed? How much alcohol was in your fuel (typically 5 to 8%)? If you can get me these items, it's not too dificult to determine your FWHP from your RWHP.

[CRUZTAKER]

I have an entire set of cats, near new, if you want to spend some more money.;)

[sabtaj1]

I agree on the IAC, do to mustang problems. Been there done that. But I would definately say somthing to do with the tune forsure. Sounds pretty weird. What happens when you are running the wrong computer code in the tune? Never done that but I know some of you guys here have. ????

[Blackened300a]

Dom, if the car didn't do this before yesterday, then check to be sure nothing got disconnected under the hood while the tuner was under there...like the MAF, or a vacuum line. Also, could be the IAC has gone south..

^^^I agree^^^
When my intake tube started slipping off, I was having problems like the ones you are talking about. My idle would surge and sometimes the car would even stall out and have a hard time starting up again.
If the car was fine right after you had the tune done then I would look for loose connections.
I had a 86 Monte carlo and the cat became clogged to the point that it would stall and the car struggled up to speed. I thought it was the transmission at first until I noticed there was hardly any smoke coming out the tailpipe in the cold morning.

[KillJoy]

OR.....

You could have toasted your Trans ;)

KillJoy

[rayjay]

Dominick, you payed good money for a tune. Take it back and have them make it right. Put two new high flow cats on and she'll run even better.

[sicilianmarquis]

i agree with killjoy on the tune, you should get a new one thats kinda guy that you got a supercharger, and now instead of creating power, it stalls your car

[HwyCruiser]

Did all the issues start after the dyno tune? If so it sounds like the tuner used his own base tune instead of the custom FIT Diablo custom tune from what you're describing with the idle and shift pressures. Was this tuner a Diablo dealer? I think Mike had his car dyno'ed around there by a Diablo dealer with good results. I'd be hesitant to lay into it until you get the tune straightened back out.

[Motorhead350]

Now the car won't shift from 1st to 2nd when I hammer on it unless I take my foot off the gas. Sounds like my tranny is about to go so I drove my truck to Detroit this weekend. All of the issues started after the tune yes. :mad:

[FordNut]

So do you still have the original tune that came with the S/C kit or did you let the tuner screw it up? The shifting is also controlled by the tune. I'd try to get it back like it was and find a more skilled tuner.

[MM_BKK]

Now the car won't shift from 1st to 2nd when I hammer on it unless I take my foot off the gas. Sounds like my tranny is about to go so I drove my truck to Detroit this weekend. All of the issues started after the tune yes. :mad:

When you say that it won't shift from 1st to 2nd when you're hammering it, what is the highest RPM or MPH you're seeing. May be because your cats are way clogged and it's not allowing your car to reach the required MPH vs throttle position to shift.

I agree with fastblackmerc about how do they know you're making 465hp to the crank. Your actual RWHP is more accurate than your guessed flywheel HP.
If they didn't even tell you your RWHP, I wouldn't go back to them.

[Brother Mike]

How much gain could one reasonably expect from 2 hi-flow cats? What is a fair price for these installed?

[rayjay]

How much gain could one reasonably expect from 2 hi-flow cats? What is a fair price for these installed?

Not sure on the exact gain, but Dom's maybe shot which would really hurt performance. Using two high flows vs stock four will yield a definate improvement. Dyno time is exspensive (ask me how I know :shake:), so I don't believe you will find any hard numbers for just the cat change out.

[Motorhead350]

The car will be stuck in the redline when I gun it. At first it would be delayed, but now it'll be stuck at 6,300 rpm until I let off. I've had problems like this with my Blazer and I fixed it by changing the tranny. :(

[HwyCruiser]

Dom, are you still on the stock tires? It sounds like your spinning the tires and bouncing off the rev limiter before the PCM can get a shift in under it. Fordnut is right about how the tune controls the shifting. If your throttle position vs. mph shifting schedule is off and/or your shift pressures are weak it's going to cause some heartache if they threw a bunch more timing at it in the upper end of the engine load and the PCM has to go into rev limiting mode because your tires can't take it. Get the tune squared away first.

[Jon01]

It's clear your tune has serious issues. Stop beating on the car or you're going to cause much more serious problems. If your tuner couldn't get it to idle or shift correctly, what makes you think they got the WOT a/f or timing close to correct?

[ChiTownMaraud3r]

The clogged cats may also be causing lots of heat damage to the trans, something that happend to my Lincoln.

[MM03MOK]

It's clear your tune has serious issues. Stop beating on the car or you're going to cause much more serious problems. ^^^ What Jon said! ^^^

[Zack]

Im sure the tune is fine.
It happened 24 hours after he left the dyno.
Im sure the tranns is shot.
100,000+ miles on a stock trans and then installing a blower combined with Dominick's driving equals disaster

[Jon01]

How many cars have you tuned Zack? Just a question, not a potshot...
There is much in the trans and shifting characteristics that are likely controlled by the tune.
The idling characteristics started after the tune too if I understood his posts.
While you're right, abusive driving after added power combined with high mileage parts down the line will cause short order destruction. But why jeopardize the motor and a fresh trans if that is the issue(which you're right, it sounds like he toasted it, whether it is due to his driving and the tune is merely a coincidence who knows)

[KillJoy]

How many cars have you tuned Zack?

HAHAHAHA!!!!

:rofl:

KillJoy

[TooManyFords]

Your car won't notice the difference between 92 and 93 octane except under WOT. Don't bother using octane boost, either...it doesn't do jack.

Correction, you car won't notice the difference unless it pings, PERIOD. There is no performance enhancement between the two octane ratings, even at WOT.

Sheesh!

john

[RF Overlord]

you car won't notice the difference unless it pings,That's what I meant.
Sheesh!Why did you feel the need to include that comment? Contrary to popular opinion, I'm not a moron.

[Zack]

I fixed his car last night over the phone.
Disconnected vacuum line.

[RF Overlord]

check to be sure nothing got disconnected under the hood while the tuner was under there...like the MAF, or a vacuum line.
I fixed his car last night over the phone.
Disconnected vacuum line.

I'm a genius... :lol:


Seriously, Zack is once again a lifesaver! :up:

[Motorhead350]

Yes that is true thanks again!!!! :cool:

[HwyCruiser]

Is it shifting ok now? I can see how a disconnected vacuum line would screw up the idle, but cause the transmission not to shift?

[TooManyFords]

Is it shifting ok now? I can see how a disconnected vacuum line would screw up the idle, but cause the transmission not to shift?

You're right JD, there are no vacuum lines to the tranny. I thought it was only controlled by TPS and Speed. I'd have to check to see if something in the PCM also monitors Load which -could- be a factor in thinking it needed to stay in a particular gear.

And where were you for the Dream Cruise?!?

:D

john

[HwyCruiser]

You're right JD, there are no vacuum lines to the tranny. I thought it was only controlled by TPS and Speed. I'd have to check to see if something in the PCM also monitors Load which -could- be a factor in thinking it needed to stay in a particular gear.


TPS and mph as far as I knew but it sounded like his WOT upshift was above his rev limiter. Maybe Zack's better over the phone than we thought. :dunno:


And where were you for the Dream Cruise?!?

:D

john

Broke and all out of kitchen passes. Been watching the Seymour thread though.

[FastMerc]

Im sure the tune is fine.
It happened 24 hours after he left the dyno.
Im sure the tranns is shot.
100,000+ miles on a stock trans and then installing a blower combined with Dominick's driving equals disaster Gotta believe part of this put a poweradder on a drive train with that type of miles asking for problems finding the weak points you will.

[Motorhead350]

I need to change the shift point to a lower rpm on the tranny, other than that it is fine. My truck was at the Dream Cruise and I was only around the Marauder area for about 45 minutes. I won't go into why, but the bottom line is both me and some of the Motor City boys were mad at each other. I can gladly move on and forget about it... in the end it was all my fault anyway.

[Jon01]

HAHAHAHA!!!!

:rofl:

KillJoy

Simple question, what was funny about it?