MM951

I developed this odd problem this morning. I had the boost set at 16-17psi (just had to try it out..AFRs were good) and it seems like as soon as was around 5K rpms with the boost set higher than 14psi I would hit a wall, barely stumble through it, and would continue at reduced power. I only tried accelerating past it once. Lowering the boost below 15psi is no problem at any rpm.

The odd thing is yesterday the car was running 100% at 16-17psi, didn't change anything and now this? I was wondering if it was a spark issue, so I replaced the plugs with new ngk bpre6 gapped to .028 and swapped ignition wires with known good ones. I also have 20" vac at warm 800-900 steady idle.

New fuel filter, fpr, fpd, newish 72# injectors (came with MAF kit)
Any thoughts?

fast951

What did change between yesterday and today? "Pressure" check your intake system at over 15psi pressure.

alxdgr8

not sure what the problem is...but you've got a PM mike

xsboost90

do you have the vitesse chip board? Sounds like the stock boost cut but im guessing its not.

shiners780

Never, never, never say "hit a wall" when talking about our cars!

Jeremy Himsel

Mike,

I'm leaning twords John's direction on this one as I've had it happen twice already where there were small leaks in the system (once due to a loose clamp and the other to a ripped IC boot) that had perfect vacuum and boosted fine until a predefined boost range (one was 12 and the other was 14). One one of them I even pulled and inspected all the boots and didn't catch the small tear that would open up after 14psi. The black cloud of fuel out the back should have been a dead give away and it drove me nuts for a few hours until I pressure tested the system.

MM951

Thanks for the advice guys, shortly after I posted the thread I saw the clamp on the fuel evap hose (MAF pipe side) was loose enough to have slid up. I thought I had it taken care of until taking my car for a spin this morning..

This time, it was hiccuping at 5K rpm at any boost (was set at 13psi this AM, lowered it to 9psi still did it) but gradually got better in the course of 20 minutes until there was just a slight hiccup and slightly decreased power. I also noticed a slight fuel smell once I got the hiccup. This makes me suspect ignition.

This only common factor between between 3/11 and today was rain. On 3/11 we had a slight rain the day before and a fairly wet morning/afternoon. Last night we had a little rain and everything is still pretty wet. I have a new rotor, fairly new cap, new plugs, formerly known "good" wires that all ohm'ed out, new sensors/harness... So I'm suspecting my ignition wires may have cracks in them that the moisture is affecting?

Any ideas or suggestions before I buy new ignition wires?

Oh, and let me just reiterate how pleased I am the vitesse maf/chipboard combo. I've had zero reliability issues (knock on wood) and almost 1,900 very entertaining miles since installing. I'm about to roll over 100K and can't wait for the next 100K

porshhhh951

You should call me dude. We should get together tomorrow and hang out.

MM951

Sounds good man, I get out of work at 9am (and am not particularly busy today)

porshhhh951

I'll give ya a call. Lets go cruise and get some coffee or something.

PS its supposed to be sunny and 45 tomorrow.

testarossa_td

Because I have to....TPS...

brrgrr

Mike - Did you figure this out ? I have the same symptoms on my black car - Ski's old "Blacky" - under WOT - at 16 lbs boost and 5000 rpm the car goes "flat" and loses power - some friends following me noted a large fireball out the exhaust - plenty of fuel - the Wideband O2 says 11.5 - 12.0 so I am thinking it is ignition related..... ?????

porshhhh951

I'm also now having the same problem. Its been raining cats and dogs here for days and when its wet out I get this miss from the ignition. All of my sensors are new, wires, plugs, etc.

Mike did you ever replace your ignition wires? If so did it solve the issue? The common factor here seems to be wet weather.

Van

LOL! An understatement!

(But I had fun at the track yesterday in the rain. )

porshhhh951

Glad to hear it. Would be a shame to tear up someone else's sheet metal.

btw I need to call you. My upholstery shop bailed on me. They can't do the install. I need to know who can install this carpet kit and lay down some dynomat for me.