Average repaint cost?

Ttype6

Well-Known Member
It doesn't seem like the lifters are pumping up because it runs just fine the moment I lift off the gas pedal, even if it's a second after the noseover. Lifters I'd imagine, would stay pumped up for a longer period of time and the engine would run like crap.
Exactly correct.
 

mikestertwo

Well-Known Member
If the fuel was being shut down by the chip to control revs,the duty cycle would drop and the fuel would be immediately be re-applied after the revs dropped restoring the engine to full power while the gas pedal was constantly to the floor.
I didn't say the fuel was being shut off. I said it looked more like the spark was being shut down.
 

hensleyt

Well-Known Member
I know you said you don’t have a spear MAS
What dose it have on this car ? I have a good OE to lone
 

Pronto

You can't knock them up with spit.
He's got a translator but doesn't list which MAF to go with the 4" intake pipe.
 

longbedGTs

high on gas fumes
I know you said you don’t have a spear MAS
What dose it have on this car ? I have a good OE to lone

The MAF is an 85mm Delphi 25168491 and is set to position 6. Translator is (I think) the 6.25 version.

I didn't say the fuel was being shut off. I said it looked more like the spark was being shut down.

Think I'll send an email to Eric and ask if there's any fuel/spark cut that was programmed into this chip. Maybe the customer specified something like that for the chip.
 

Eric Stage I

TurboTweak Guy
That chip has a MAF Lock, so once it locks onto to 255, it won't let go until you start lifting off the throttle. That's why you see that funny MAF signal after the boost starts dropping. Also, it's probably flooding with fuel at that point.

The last time I saw a log like that, the car had an air filter that was collapsing under high boost, one of those real long filters.
 

longbedGTs

high on gas fumes
That chip has a MAF Lock, so once it locks onto to 255, it won't let go until you start lifting off the throttle. That's why you see that funny MAF signal after the boost starts dropping. Also, it's probably flooding with fuel at that point.

The last time I saw a log like that, the car had an air filter that was collapsing under high boost, one of those real long filters.

Thanks a ton! I was just about to send you an email.

Also, you're right on the air filter.

AiQEyEy.jpg
 

mikestertwo

Well-Known Member
This is the quote of what you said.
Your taking it out of context !! Read the whole thing. Let me dumb it down for you. I said it appears the fuel is being shut down but the injector duty cycle does not confirm that so I said it might be an ignition issue. Then in a later post I said check to make sure the damper isn't moving out of the crank sensor. ie. crank shaft end play.
 

Ttype6

Well-Known Member
What chip are you running? It almost looks like it has a rev limiter on it. It looks like the fuel is being shut off at around 5900 rpm even though the injector duty cycle is still up so maybe spark is being shut down?
Here is your complete post so you can't accuse me of taking your words out of context. You say that you thought it looked like a rev limiter issue and noted that the IDC didn't drop. The fact that the IDC didn't drop proves that fuel wasn't being cut off which is the only way that these chips limit revs. I'm simply pointing this out for someone else who comes along and reads your post so they can put rev limiter out of their mind and look elsewhere. Just like it can't be valve springs,it can't be a rev limiter issue because power would immediately return as soon as the revs dropped.

Calling me dumb doesn't do anything to help your rev limiter theory.
 

No disintegrations

Well-Known Member
There's 2 parts to the problem. Part 1 When it bogs down and stays until he lets off.
Part 2 is it stops pulling after 5900 or 6000. That could very well be valve springs.
 

Ttype6

Well-Known Member
There's 2 parts to the problem. Part 1 When it boys down and stays until he lets off.
Part 2 is it stops pulling after 5900 or 6000. That could very well be valve springs.
Part 3,the op left it to the floor until the rpms dropped to 1,200 rpm with no recovery. It can't be valve springs. The most plausible theory so far is the one that Eric gave. It lines up with the evidence.
Do you have experience with inadequate spring pressures?
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
I mentioned earlier in this thread that these engines, when they fall on their face, usually happens in high gear...3rd gear. Good luck to the OP and for Eric dropping in for his insight.
 

longbedGTs

high on gas fumes
Did you remove the filter and record the data?

Won't have a chance to work on the car until this weekend hopefully and planning to start with the governor mods then but I could swap the air filter and run it and take a log just for the heck of it. I may be able to use a short K&N style filter from another car that has less of a chance at collapsing. The '86 has the same length filter so I won't bother with that one. I'm guessing once the MAF locks onto 255, it'll stop accelerating and just stays at the power level it was at when it reached 255? Just trying to understand how it will behave and what to expect.
 

Ttype6

Well-Known Member
Won't have a chance to work on the car until this weekend hopefully and planning to start with the governor mods then but I could swap the air filter and run it and take a log just for the heck of it. I may be able to use a short K&N style filter from another car that has less of a chance at collapsing. The '86 has the same length filter so I won't bother with that one. I'm guessing once the MAF locks onto 255, it'll stop accelerating and just stays at the power level it was at when it reached 255? Just trying to understand how it will behave and what to expect.
To test Eric's theory you need to remove the air filter and run without it and you need to do this before changing the governor.
How long is your filter? I ask because it looks like the same filter I have. The dirtier it is,the sooner it will collapse.
You asked in an earlier post if that turbo needed to be run at 30 PSI. It doesn't need to be,but it will produce alot of power at 28-30 psi in your application.
 

longbedGTs

high on gas fumes
To test Eric's theory you need to remove the air filter and run without it and you need to do this before changing the governor.
How long is your filter? I ask because it looks like the same filter I have. The dirtier it is,the sooner it will collapse.
You asked in an earlier post if that turbo needed to be run at 30 PSI. It doesn't need to be,but it will produce alot of power at 28-30 psi in your application.

Not sure on the filter length or age. What a wake up call this will be if it is the problem. I should have given more thought to the condition of the air filter...but honestly, it didn't even cross my mind. :oops:

Ok, will run it without a filter and report back. Since the car has never shifted into 2nd gear at WOT, I have no idea when it will change gears(will be over 5,900 at least). At what RPM should I lift off the gas(if it doesn't shift into 2nd) to avoid spinning it too high and possibly causing valvetrain damage or worse?
FWIW, the reason the shift points are so out of whack is because the trans is suspected to be from a Monte Carlo or SS or something other than a GN. It doesn't have the BRF valve body and the governor gear is green.

Awesome to know about the turbo. The 3200 stall converter seems to work well and spool up isn't bad at all.
 
Last edited:
Top