Quicker at part throttle ?

[BOP4ever]

ok my car is wired....
Can a fit car bog ? Like secondary's coming in to fast on a qjet carb ?
My car litters seems to pull harder if I go about 1/2 in from a dead stop vs flooring it.
Wot and it may spin the tires, or it may not .
1/2 throttle and it breaks loose as soon as the boost hits .

To make these even wierder it does not always seem to bog, some times it smoke the tires going to wot and makes me pedal....
It may feel like a 11 sec capable car one day and a 14 second Slug the next .

 

[BOP4ever]

Dang iPad auto correct ! Sorry the jibberish is hard to understand.

 

[Bescurred]

You have a scanmaster? What does your O2's say?

 

[TomD]

I had a similar issue. WOT and it was a dog. Turned out to be my spark plug gap. Gapped to .028 and cleared it right up. Pulls hard all the way now. Something maybe worth checking out. I replaced my maf, and map and it still did it.... should have checked the gap first.. whoops.

 

[earlbrown]

Might want to swap in a known good TPS too. That's easy enough to try.

 

[TomD]

Might want to swap in a known good TPS too. That's easy enough to try.

Yes or verify tps voltage on the scan master. I made sure to check that too.

 

[BOP4ever]

Thanks guys, the tps is a little low at wot 4.5 I think . O2 is 735-760.
Plugs are at .030

 

[No disintegrations]

If I want to rule out pump shot as a problem I slowly press the throttle. If all is good then I investigate the so called pump shot further. Pump shot is only needed when quickly stabbing the throttle.

 

[V6sleeper]

Had a similar problem many years ago turned out to be a faulty atr super-pump.

 

[TomD]

Thanks guys, the tps is a little low at wot 4.5 I think . O2 is 735-760.
Plugs are at .030

I think that tps reading is right where it should be.

Another cheap thing to check is get yourself some maf cleaner and spray your maf sensor. If you have a maf translator, make sure all the connections are secure, check the dip switches. If you have a map sensor and want to check that, it's about $80 for a new one.

Was the car ever running well for you under WOT? I've had my coil pack go out before and running on 4 cylinders, it was a big slouch. Keep checking and ruling out things with air/fuel/spark delivery. Is your fuel pump hot wired?

 

[Chuck Leeper]

the tps is a little low at wot 4.5 I think

if it actually 4.5, that's not low.. It's OK. Check the sweep to be sure there are no dead spots.

 

[20psiofevil]

Ever adjusted throttle linkage? Happened to me once when I switched to a 70mm tb, stab the gas and the throttle blade would not only open but open to much and close on itself. Voltage would hit 4.8 volts. Easy to check for, lay something heavy on the accelerator pedal and inspect the tb blade.

 

[BOP4ever]

It is inconsistent... Sometimes it seems fine.
Same day I take my friend to lunch and its feeling great instant boost from a roll it breaks loose at 1/2 throttle nearly instantly, but I have to stop behind someone on the way home turning left and I floor it to leave the pick up stopped about a foot off my bumper and it just squats and moves barely pushing me into the seat.
I'll check the TPS . Throttle cables and body are all stock, same for maf etc...

 

[earlbrown]

Oh, lord.... That MAF belongs in a museum not on a car.

Even it was running perfect, I'd recommend tossing it for a Translator and an updated MAF. (then notice it runs even better).


If you know anybody local that has one, beg, borrow, or steal it to rule out your stock unit.


Since you're issue isn't consistent, that's why I lean towards things like TPS, MAF etc... sometimes they fail without it being 100% of the time. It'd be a good idea to tape a fuel pressure gauge to the windshield too. It'd be nice to know your have the correct amount of fuel when it acts up.

 

[BOP4ever]

Ok I checked the TPS and reading the scan master key on engine off I observed 4.0 to 4.35 at wot. I had to press really hard to get 4.35 may have a floor mat issue ... Didn't check but that would be consistently in the car while this has been happening. Could this have caused my weak performance ?
Oh and Btw the low end read .43 and it seemed to respond pretty linear.

 

[626gn]

Your floor mat could very well be preventing higher TPS numbers but as long as you're seeing over 4.0 I think you're ok. Anywhere from 4.2 - 4.8 is where most set it. Regardless of where it is in this range makes no difference in performance. As mentioned the stock maf's are notorious for being flakey. See if you can find a known good one near you to rule it out. Better yet, change it to a more modern maf (& translator). If you can't find a stock maf near you I have an known good oem maf I can send you to test.

 

[BOP4ever]

Doesn't the maf kinda get taken out of the loop at WOT? It gets saturated pretty quick I think reading 255 if I remember some of the old Turbolink logs I used to play with. I thought the maf was just a factor for part throttle driving .

 

[earlbrown]

lay on the floorboard and find where the throttle cable passes through the throttle pedal. Put a zip tie on the cable to act as a shim and your floormat problems will be solved.

 

[BOP4ever]

lay on the floorboard and find where the throttle cable passes through the throttle pedal. Put a zip tie on the cable to act as a shim and your floormat problems will be solved.

Thanks for the tip!!