Car hesitates between 3k-4k rpms at full boost

[Cool Mr Steve]

Interesting problem here... I have a hesitation problem when I'm at full boost between about 3200 RPM and 4200 RPM, give or take a few RPMs. Accelerating up to full boost is no issue, but as soon as it hits full boost (about 14-15psi) at around 3200 RPM, it stutters. If I hit full boost anywhere in that range, it stutters. But if I accelerate w/o hitting full boost past that range, no stuttering issue. My car is running rich, as can be seen from large amounts of deposits on my spark plugs after only 10-15 miles. I have a AFPR that I'm not exactly sure how to tune, and a SAFCII that I am in the process of purchasing a pocketlogger for tuning. Should I do something to lean out the entire system with the AFPR or lean out between those RPM's with the SAFCII, or does that even seem like the problem??? BTW, its not spark plugs or wires...

 

[Eclipsemblue]

ya i seem to have the same problem once i hit like 5,000rpms at full boost the car violently shakes and i replaced my spark plugs and wires, it use to stutter at like 2,800rpms before that. I also notice a large buildup on my spark plugs within 1,000miles, strange shit and my car only has 43,000 miles on it.

 

[ECLIPSE4x4]

Here are a few questions for you.

Spark plugs: What kind and what gap?

AFPR: DO you have a gauge, if so what is it reading at idle?

Boost leak check done?

When you say full boost, what is full boost? 10 PSI? 25 PSI? what?

 

[Cool Mr Steve]

Spark Plugs - NGK BPR6ES
Spark Plug Gap - .028
Boost leak test - Free of leaks
AFPR at idle - 29 psi

 

[Cool Mr Steve]

Oh yeah, and it's listed above, full boost is approximately 14-15psi.

 

[97spydagst]

mine also is gutless from 4k to 5k then after that it pulls hard and it spools before 3k with a 14b with s16g ported housing

 

[Cool Mr Steve]

anyone????

 

[Crawl]

i am having same problem on mine, same plugs, new wires, new fuel filter, cant figure it out

 

[karbon]

Why is your fuel pressure so low? It's supposed to be 40 with the vac line off.

 

[sjgYFZ200]

Do not bump your threads.

 

[tt281gt]

I had a similar problem and I vote for boost leaks. thats if you have already changed your plugs and wires (and plugs are gapped correctly).

 

[ECLIPSE4x4]

Why is your fuel pressure so low? It's supposed to be 40 with the vac line off.

You are correct, the FP is way to low.

 

[Cool Mr Steve]

My bad, my fuel pressure WITH THE VACUUM LINE OFF at idle is 50 psi... Probably an issue, so I'll lean it out to 40 tomorrow...

 

[Spool_Me]

my 96 talon is doing the same thing. It gets to full boost @ 13 psi and then starts sputtering real bad and the needle on my gauge (autometer) flutters real fast between 12.5 and 13.5 psi. Also my air/fuel gauge jumps from rich to alomost lean so fast that the whole gauge is lit up constantly between those points. Any help on this matter would be great...I am getting frustrated and obviously no closer to solving the prob. thanks

 

[prophecymiller]

I know this is an old thread, but what was the solutions to your problems???

 

[beastawd]

i have the same problem just installed my turbo t3/t4 and then 3 days after driving the car started acting funny i thought it was my intercooler piping but it was all checked for leaks. egt gauge is reading at 14 so i guess the car is not running lean someone told me to disconnect the tps and the car did the same thing just wondering would the plugs and wires foul out that fast or should i look else where

 

[Locutus78]

I just had the same problem. It turned out that the outer nut on my egt tap had loosened. So it was ok at low rpm's but as soon as the exhaust started really flowing I hit a flat point untill I shifted and lowerd the rpm.