Engine wont go past 3500 rpm/positive boost, bogs down

[New2Talon]

Took her out today after firing it up for the first time last night, and am having some problems. I'm not sure wether it is rpm related or boost related, but at 3500-4000 rpm the car will bog down and not have ANY power what so ever, but the car also bogs down when the boost (gauge) goes positive. Since boost starts to kick in around 3500-4000 rpm i'm not sure which it is. Even when I downshift, I still cannot get the car past 3500 rpm. I can get going, but either need to keep under 3500 or under positive boost levels. The car drives fine until either of those points.

When i'm idleing I can get the car up to redline with no problems, but once I let off the gas, the rpm's shoot waay down, enough to stall it out. If I rev it then get off the gas slowly the car will idle fine at 1500 rpm (i need to adjust the tb, so thats why its idleing high..)

Could a vacuum line cause this. I had a bunch of things off over the winter, and could have possibly forgotten to reconnect one.

Anything I can do to see wether it is rpm related or boost related?


Help?

Thanks

[dj_rice]

Vaccum line...or check your IC connections...maybe one is loose somewhere

[stevo 27]

does it happen to shout black out of the exausht?

[dj_rice]

Originally posted by stevo 27
does it happen to shout black out of the exausht?

Huh?

[Mike w]

its gota be a vacume line off the intake, that exact same thing happend to me when i forgot to reconect the line back up to mine. just look arround and see if anything got disconnected.

[stevo 27]

Originally posted by dj_rice



Huh?

sounds kinda like mine but my dump black smoke out of the exhaust so i was wondering if we have the same problem

[New2Talon]

It does, but im not worried about that. The clip i have came with 20% bigger injectors (540) and is still running on stock ecu, so yes when im on the boost it does blow black smoke, but it ran fine rich like that last year, so thats not a big concern.

I will go out and check all my ic piping/couplers, as I'm thinking it is a major boost leak somewhere or a unconnected vac line..

I didnt have any time to check it this morning when it happened, as I was already late for work, just had time to baby the car home, post up on here and head off for work in a different car.

edit
if it was a boost leak, shouldn't the engine still run/drive like a NA engine? Only difference would be, when I should be boosting, I just won't be getting any extra "kick". I shoudn't be bogging at a certain point should I?

[stevo 27]

Originally posted by New2Talon
.

edit
if it was a boost leak, shouldn't the engine still run/drive like a NA engine? Only difference would be, when I should be boosting, I just won't be getting any extra "kick". I shoudn't be bogging at a certain point should I?

no it wouldnt run like an NA car because the MAF is readin how
much air is being sucked in and tellin the TPS to dump the amount of feul needed for the amount of boost now when the metered air
excapes theres still all that feul but no air to burn it off
therefor way to rich and bogging

[Milk2%]

AFM. Check the voltage

[stevo 27]

im having the same problem as your pretty much but
my TPS and MAF voltages check out so im stumped i hope yours
is an easier diagnosis

[New2Talon]

Well I found my leak. (I hope...) One of the nuts for my bov flange came off, and made it loose. I didn't notice it at first because it was on the underside of the bov, and when I quickly checked it on the side of the road, it still seemed tight and secure. After the drive home, i noticed it was loose, and because the bov is so close to my tb I'm guessing thats how the small leak made such a big difference.

I threw a ziptie through the flange hole and tightened it down, took it for a spin, and it seemed to have cleared things up. When I cut the ziptie off, and loosened the bov, the problem came back.

Off to find another bolt/nut/set of washers tomorrow to secure it properly, and I guess we'll see if that was it for sure.



Stevo, are you randomly bogging, or does something trigger it? I had similar symptoms, except it would only bog on WOT under a heavy load (going uphill) at higher rpm's. Seemed like fuel cut, the car bogged so bad...

Changed the plugs out (just the plugs, no other ign comp) and problem went away. I'm running copper bkr7e's gapped at .028" and change them every oil change. What are your plugs gapped to? How old is the rest of your ign system?

What size injectors are you running? I'm only pig rich because of my 20% larger injectors and no tuning...You shouldn't be that rich on stock injectors...

[stevo 27]

mine will bog for a week or 2 then go away for a week or 2
back and forth
and same as you wot under heavy load and once i hit 5000rpm
and it runs extremly slow until it bogs also




plugs gapped to .028

[stevo 27]

but even tho its blowing black the plugs are white

[New2Talon]

Well securing the bov seemed to have cleared things up. So that problem is fixed...now I just need to find out where I'm running from in the rear.

Sorry stevo, but I cont know what else to try. Bogging should either be too much fuel/fuel cut/bad ign. It doesnt seem intermittent, but random, so i dont know what else to suggest.

[stevo 27]

yea im searching for a vac leak and such tryin to fix it haha
congrats on fixin yours

[dubs20]

okay yeah my damnn d16z6 boosted, the engine redlines at 4200 rpm.... and it dogs out dont go hirer then that so would it be the same thing the BOV?

[New2Talon]

if your redline is 4200 (thats low) then it wont go past 4200 (rev limiter) for safety reasons.

Stevo, what mpg are you getting?

[dubs20]

lol k it was working fine my red line would be at 7200rpm

and then when i was driving it bogged out and it started redlining at 4200rpm so obviously it cant be safety reasons?

[stevo 27]

im gettin mabey 5k per gallon

[stevo 27]

discovered the problem vac leak
now to fix it

the stock boost controller under the block that the vac line
from the wastegate actuator meets with a vac line from the intake the intake nipple that the vac line slides over has been snapped off dont fuckin know how that managed to happen but now just gotta find one

i missed it because its hidden on top of the axle and under the block was tricky to find