seanrot

iTrader: (2)

I got the turbo install completed last night but since I have a staight pipe into a glasspack thought it best to hold off on the testdrive at 11 pm in a residential area.

So got up this morning around 11 and took her for a test drive. Things didnt go as I wanted. Go figure at least it started

Need some help.

She runs good till the boost hits about 3000rpms, then she back fires to all hell and back, I mean loud duck for cover backfires. Running too rich what you think?

What should I run the timing on a turbo 12a? The distributer is locked in advance position. I tried moving it a little at a time and test driving, no luck there.

Any ideas on what to look for?

79+80+84_rx-7

some kind of fuel problem....





Whats your fuel setup?

79+80+84_rx-7

it could be starving for fuel.... like boost is pushing it back through the carb.... or pump is pushing too much.... play with your regulator....

seanrot

iTrader: (2)

GSL SE fuel pump and mallory rising rate regulator set at 6 psi

web777

What kind of carb are you running?

web777

I looked at your other post and it looks like you are running a Weber. You're most likely running real lean when boosting. Also put you dizzy back to the stock timing and see how it does.

seanrot

iTrader: (2)

I thought backfires were a sign of running rich?

web777

It can be both. The rich back fire is a little muffled. Does your car accelerate faster when it starts to boost?

seanrot

iTrader: (2)

nope, she is boggin out

seanrot

iTrader: (2)

ggggrrrrrrrr dp

cantstopa-7

well, get rid of the glass pack for one, theyre more restrictive than people think. but probably nothing to do with the backfire, also i noticed youre blowing through the carb-correct? if so is the carb built for this application
? if not that could be part of the problem. also- youre ignition is distributer with vacum advance no? so check youre vac line to the dist -it may be in the wrong place -let us know what happens.

fatboy7

If you want to find out what the problem is without blowing up your motor, I suggest you invest in some diagonostic equipment.

I'd recomend a fuel pressure gauge, an oxygen sensor (I strongly suggest a WB, but a NB is better than nothing), and perhaps an EGT.

Oni-kyan

If Robert from Rotary Shack was alowed on this forum, he would have helped ya!

web777

OK, You're running lean. You need to jet up. Forced induction requires a lot more fuel!

mwatson184

Where is your boost reference line for your regulator coming from?

If you have a fuel pressure gauge and a hand pump then make sure that fuel pressure is rising as pressure increases, you could have a faulty diaphram in the fpr.

Marques

Junia

why isn't he allowed on this forum??

82streetracer

iTrader: (1)

yeah, What?

hornbm

good question

FB II

it's probably because i'm fat.

hiboost7

i agree, i also think you are running lean....when boost kicks in you have no fuel to feed it, therefore engine dies down (bogs) jet up, and get a fuel pressure gauge and check your pressure and make sure its rising with boost levels, if not ditch that crappy fuel regulator that replaces the best eva

Directfreak

iTrader: (2)

Also make sure the boost reference line for the FPR only sees boost - NOT Vacuum.

Drj419

yup ur running lean if ur bogging. But hey play around with ur tuning ull prolly fix the prob that way

seanrot

iTrader: (2)

Do to the lack of exhaust at this time, this is a loud MF... I will be postponing any tuning till I finish that.


This is what I have for an exhaust, it damn loud.


My FPR is getting its signal from the carb hat as well as my boost guage. It doesnt show vacuum at all.

Time to go buy some more jets

evita

6 psi? Seems like too much fuel pressure to me. I could be wrong.

9d7gst

What kind of spark plugs? I know going colder in turbo apps is allways better. Also spark gap can make a big diff in pistion engines. Mabey different because the plug isnt in the chamber but worth a try.