(wot) hesitation please help

T

turbo boostin

New member
Hello everyone. I recently encountered a problem with my syclone truck. At wide open throttle there is no response and it hesitates and just dies or it starts to pop out the intake.. It does run good if I do not use the turbo and it shifts great with no problems. The turbo spools fine and boosts good, but it just does not run like the way it use to. I have done many things since I have had it. Things done include and all are quality a/c delco parts. Cap and rotor, wires (taylor), platinum spark plugs, fuel filter, air filter, 02 sensor, TPS, wastegate solenoid, Mobil 1 10/30 synthetic. So WOT is my problem and it just hesitates at makes a popping noise out the intake. What could be the problem? Any input would be greatly appreciated. Thanks
 
Turbo6

Turbo6

10.20@131.8
Re: (wot) hesitation please help

turbo boostin said:
Hello everyone. I recently encountered a problem with my syclone truck. At wide open throttle there is no response and it hesitates and just dies or it starts to pop out the intake.. It does run good if I do not use the turbo and it shifts great with no problems. The turbo spools fine and boosts good, but it just does not run like the way it use to. I have done many things since I have had it. Things done include and all are quality a/c delco parts. Cap and rotor, wires (taylor), platinum spark plugs, fuel filter, air filter, 02 sensor, TPS, wastegate solenoid, Mobil 1 10/30 synthetic. So WOT is my problem and it just hesitates at makes a popping noise out the intake. What could be the problem? Any input would be greatly appreciated. Thanks
Click to expand...

You might try UR6 NGK plugs gapped at .030. What is the gap on your plugs now? The platinum plugs could be the problem. In most applications they dont like to fire under lots of boost.
 
T

turbo boostin

New member
Re: (wot) hesitation please help

The spark plugs are gapped at .035 and I inspected each one and all are the same gap. I do know that if the gap exceeds it will really make the truck run like crap. The problem is also when I push the gas pedal the turbo spools up, but the boost catches up slow and before it use to be real responsive. When I first take off at a stop I have to tap the gas a couple times because when I first press the gas on take off it just does not respond, but when I tap the pedal and slowly press the pedal it starts to build rpm and runs good without building boost. I'll try the plugs that you are talking about and see if it makes a difference. Thanks for the input and any other suggestions would be great.
 
Turbo6

Turbo6

10.20@131.8
Re: (wot) hesitation please help

turbo boostin said:
The spark plugs are gapped at .035 and I inspected each one and all are the same gap. I do know that if the gap exceeds it will really make the truck run like crap. The problem is also when I push the gas pedal the turbo spools up, but the boost catches up slow and before it use to be real responsive. When I first take off at a stop I have to tap the gas a couple times because when I first press the gas on take off it just does not respond, but when I tap the pedal and slowly press the pedal it starts to build rpm and runs good without building boost. I'll try the plugs that you are talking about and see if it makes a difference. Thanks for the input and any other suggestions would be great.
Click to expand...

That sounds like a timing problem or like its running on 4 or 5 cyls.
 
T

turbo boostin

New member
Re: (wot) hesitation please help

It runs great on the freeway and the turbo spools up and boost good as well. All cyliners are firing and the timing is good.
 
T

turbo boostin

New member
Re: (wot) hesitation please help

Well, when I make a complete stop and start to go into the pedal it runs bad, but when I let off and press the pedal again it starts to take off smooth. The problem is when I am at a stop and try (wot) it just hesitates and I noticed when I checked under the hood that the popping noise is coming from the turbo by the elbow. The boost is there and it spools great. I am assuming that it might be a bad relay cut off for the fuel or possibly the fuel pump is going bad. Any input would be great.
 
purdaddy

purdaddy

I ate a big red candle.
Re: (wot) hesitation please help

I'd keep an eye on your boost gauge (you do have an aftermarket gauge, right?
icon_wink.gif
)
What does boost do just as you go WOT from a stop?
How does it idle? (you mentioned popping noise....)

Also when cruising, does boost pressure drop down quirky like, without any RPM changes?

What wastegate did you put in it? Stock? Aftermarket?

I would dump those Platinum plugs like the plague
2cents.gif

Sounds like you might have some boost/vacuum leaks........again, my
2cents.gif
 
T

turbo boostin

New member
Re: (wot) hesitation please help

I do not have an aftermarket boost gauge, just the stock one. When I try to do (wot) from a stop sign, it just starts to hesitate and the rpm's drop and do not increase. As far as idling, it is good with no problems. There is no sign of any misfire at all. When I am cruising the boost stays the same with no rpm changes. The truck is all stock and the wastegate is original. I did put a new wastegate solenoid, TPS, and O2 sensor. I will change the plugs to see if it makes a difference. Thanks for the input and keep them coming.
 
DynaGlide

DynaGlide

Ton-Eighty
Re: (wot) hesitation please help

Do a pressure test, and listen for vaccuum leaks. Also, be advised that the throttle body is known for leaking around the steel shaft on which the throttle arm and butterflies pivot.

Cracked plug porcelain?

Platinum plugs are notorious for not working correctly with sytys.

The symptoms you describe could be any number of problems. However, we never seem lucky enough to have "textbook" or "routine" problems. Good luck.
 
T

turbo boostin

New member
Re: (wot) hesitation please help

I did the inner tube trick and there was no sign of any vacuum leaks. I changed the double platinum spark plugs to a/c delco spark plugs AC R42TS and since I took off the front right rim, I also decided to go ahead and adjust the wastegate. Wow! Did I notice a difference. The plugs made it run way better and now I can hold down the brakes and accelerate and the turbo responds with a fury leavin burnout marks on the pavement. Since I adjusted the wastegate, the turbo is more responsive than before and reacts way faster than before. Thanks for all the input to everybody that responded to this post. I appreciate it and any other input that I need to know about would be great
 
BLACK92TY

BLACK92TY

It's never enough
Re: (wot) hesitation please help

hijacked.gif


I've been having some issues with hesitation also. Mine is very minor but annoying. The boost will spike and tach flutters but then it jumps on its feet afterwards. It's usually mainly under partial throttle (very rarely under WOT). Hesitation also very rarely occurs when I put 100 unleaded in and the boost is very obedient. When I run 92/93 the hesitation is almost guaranteed.

Today I got off work early to throw on some pads along with a fuel filter and TPS. I also just checked my ECM1 and B fuses to make sure it wasn't something petty. All my ignition is brand spanking new. I know I still need to check my vac lines. Thought I might actually get rid of this crap. But....hesitation still exists!
motz2.gif


Maybe I'm just desperatley in need of a tune. But I need to get access to a scantool forsure. I'm not too keane on pulling it apart to see if the walbro holding up alright. No datamaster either.

Any suggestions? Anyone experienced this?
 
BLACK92TY

BLACK92TY

It's never enough
Re: (wot) hesitation please help

Oh yeah....

Is there a certain way you need to position/tinker with the TPS? I just literally pulled the old one and popped on the new one.

Thanks
 
InvisiBill

InvisiBill

Active member
Re: (wot) hesitation please help

turbo boostin said:
I changed the double platinum spark plugs to a/c delco spark plugs AC R42TS...
Click to expand...

http://www.sportmachines.com/maintenance/beginner.php
Replace spark plugs with AC CR42TS, gapped at .032-.035, every 30,000 miles. (The CR designated plugs have a heavier electrode than a R42TS.)
Click to expand...

I personally find the NGK UR5's to work better, and they're actually easier to find around here.
 
Aeroking

Aeroking

e.i.
Re: (wot) hesitation please help

dig this topic up again.

I'm having the same problem, except my RPMs stop at 4500 in 3rd gear only.

I'm running UR6s with a 22 gap, 20psi of boost, with meth, 22* timing. new cap/rotor, taylor 8.8 wires.

the truck runs fine under low boost, but in high boost in high RPMs it flutters, and skips RPMs, and blows the intercooler off. Boost remains stable, no KR, trans isnt slipping.
 
Last edited:
DynaGlide

DynaGlide

Ton-Eighty
Re: (wot) hesitation please help

Not saying that this is your problem, but some bump back down to UR5s when they add methanol because of the decreased intake temperature. It may not be incredibly easy to change the plugs out, but at least it's relatively inexpensive.
 
You must log in or register to reply here.
Top