Sputtering/Hesitation - under boost

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A92Supra4Life

A92Supra4Life

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Okay I realize I'm a noob... but I've searched and searched, even talked to DrJonez and Jeff Lee... and both are starting to run out of ideas.

To be as thorough(sp?) as possible, I started out replacing all the stock clamps on the intercooler pipes as the one that goes from the turbo to the IC wasn't tighening anymore. While I was at it, I inspected the pipes also. My power steering and a/c were leaking, I don't use either, so I cut off the belts. I put the IC pipes back, went to start it, and it wouldn't idle worth crap, and couldn't rev past like 2500rpms w/o shooting mad flames out the exhaust. I consulted with a couple people.. they mentioned timing, and it was, magically it jumped... I reset the timing, with the terminals jumpered, and set it to 10-11 degrees. Idled perfectly afterwards... but I couldn't rev past like 2500-3000 in the boost range(anything after 1psi, while driving). I ended up changing to new plugs(NGK's, gapped to 0.30 or 0.8mm) Tried different AFM's, coil packs. I'm running open turbo elbow due to someone using my exhaust and crushing it. Also using a Tial BOV. I recently did a KS rewire, so there's not a SINGLE code popping up, as that was the only one.

I forgot to mention that I can rev ALL I want in neutral.

I do have two vids. I will post links to them. The vids explain best what is happening.

Thanks in advance guys!! I know we can get to the bottom of this:icon_bigg

http://www.zippyvideos.com/1330931296229236/mov05775/ -- revving freely in neutral
 
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marlonvip

marlonvip

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Sep 2, 2006
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Hi there,

think I have sort of the same prob....

major hesitation when boosting and very poorly throttle response...
change the plugs and wires, didnt help
set the timming, didnt help
changed afm, didnt help

and I keeping getting the codes 14-34-51

tried and fix everyone of those .........still runs bad:-(

hopes someone with some wisdom scimes in and helps:)

Marlon
 
MDCmotorsports

MDCmotorsports

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Ok you've got a couple of problems here.

1.)Either your gauge is wrong, or you're out of gas. That will make it sputter every time.

2.)You're running a narrow band o2 gauge. Big no no. For reference only, not for tuning an safc

3.) You're running a safc with no wideband support. Another big no no.

You said you just snipped all the belts under the hood. Stupid question, but the alt is still hooked up and charging right?

4.) What is your order on the plug wires to the coil packs?

5.) Turn your safc settings to zero as in fuel compensation. What is your Hi/Lo throttle % settings?

6.) What fuel system are you on?

7.) When you tightend the lower boost hose, how crusty was it? If it was an old hose, I'll bet you lunch you split the thing when you gorilla tightened the new clamp.

Let us know....
 
A92Supra4Life

A92Supra4Life

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1. It is close, but before I took the video I put $5 dollars in just to make sure.

2.It is for reference only.

3.The wide band is installed, but all settings are at zero.

Yes, Alt belt is still on and charging. ONLY A/C AND PS were removed.

4. I will go check.

5. They are at zero, I believe lo is 69% and hi is 70%

6. Stock fuel pump, stock injectors, bypassed j-tube, Aeromotive AFPR... set to 42psi(as instructed by someone on the boards)

7. Hose is nice and soft. Not cracked or anything.
 
jdub

jdub

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A92Supra4Life said:
6. Stock fuel pump, stock injectors, bypassed j-tube, Aeromotive AFPR... set to 42psi(as instructed by someone on the boards)
Click to expand...

Drop your FP to 25-30 psi with the vac line connected ;)
Easy to do...Give it a try without doing anything else and report back.
 
A92Supra4Life

A92Supra4Life

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Okay, dropped FP to 25-28psi. NO MORE HESITATION/SPUTTERING... BUT under WOT it doesn't really move, and while cruising, if you hold the gas, so you maintain speed, no accelarate or let go, but MAINTAIN, it'll like misfire sorta.

We're getting somewhere fellas.. :-D
 
jdub

jdub

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MDCmotorsports said:
5.) Turn your safc settings to zero as in fuel compensation.
Click to expand...
Ok...first things first...make absolutely sure this ^^^ is done

Then...


MDCmotorsports said:
2.)You're running a narrow band o2 gauge. Big no no. For reference only, not for tuning an safc
3.) You're running a safc with no wideband support. Another big no no.
Click to expand...
Get a wideband!!! Playing with the fuel delivery without being able to see what's happening to AFR is like a blind man playing with dynamite and matches. Really consider getting an upgraded fuel pump. If you go lean under boost due to the SAFC or the pump pressure dropping off = detonation...it can really ruin your whole day ;)

Listen to what MDC is trying to tell ya...you do like your motor don't ya?


Now...the sound you're hearing, does it sound like a very low popping noise? And does it occur only under vacuum?

You're using NGK coppers? BCPR6ES or BCPR7ES?

How old are your plug wires?
 
A92Supra4Life

A92Supra4Life

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Well, the AFC is at zero, and the fuel pressure was set so high because that's what I was told. I didn't mess with the AFC, because I'm waiting to buy a Walbro fuel pump, some RC 550's, and upgrade the turbo, and then go get it dyno-tuned.

The plugs are BCPR5EY-11. I should probably get new plugs?... since they aren't either of what you said.

Plug wires are probably pretty old... I will try changing them out.

And yeah, I do like my motor :-D no rod knock like my last one

As for the noise... it's not really a noise to it.. it's more just the feel it will kind of jerk you back and forth lightly... I believe it's actually a misfire maybe.
 
jdub

jdub

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Yes...get new plugs...how much boost are you running? Hi boost = colder plug. Another option is the Autolite 3923.

And change the wires...MSD is good for the $$$. Here's the cheapest place I've found them (gonna get some myself):
http://www.fasterthanthem.com/product.php?productid=59137

Your smart not to adjust the SAFC right now...add a wideband to your wish list from above ;)
 
jdub

jdub

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If you use the NGK's, run the BCPR7ES...they should work fine for that amount of boost. A .030" should be fine as well. You'll have to change out the coppers more ofter than the platimums or iridums, but they seeem to work the best in this motor (Autolites too).

BTW - if you don't have an exhaust, your car is a bit on the loud side huh? :naughty:
 
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