zheka

Like the title says, its my first week of driving my 93 fd. Never had rotary engine before. So anyway I think the vehicle got some problems with it. First of all the only none stock part on it is 3" downpipe, hks catback, and k&n airfilters. vehicle got 40k miles on it,
my problems are:

10-12 miles/gallon
vehicle idle jumps from 900-1500, (when i turn a/c on, rpm stays steady at about 950)
vehicle sometimes stoves when i get to complete stop (rpm drops to 400-500 and engine shuts off)

i personally think that i ether got a vacume leak, or engine misfiring.
oh and one other thing. when i install boost gauge to intake manifold, when engine idles i got vacuum at 17, and when i accelerate vacuum increases to 20, ( i didnt see any boost from intake manifold, even when i had rpm at 4500.)
I only being driving this thing for a week. don't know anything about them. please any useful information would be helpful to me.

cptpain

iTrader: (1)

check for any loose or blown vacuum hoses and cracks in the i/c coupling.

make sure the MAP sensor vacuum hose has not blown off.


where exactly is the boost gauge plumbed into?ie; where is its source of boost/vacuum?

pyro_racer_0016

were u sitting still when u did said vacuum test.

evot23

iTrader: (17)

check throttle position sensor and adjust. If you have vac problems, they may be the source for your issues.

10-12 mpg...that's all relative on how you drive and the condition of your car but does seem low. My modded R1 got 15 in the city, 20 highway..

oo7arkman

iTrader: (2)

Like it is mentioned above, check the tps settings (do a search on here and you will find it.) If that is in spec then it is most likely that you have busted, cracked, damaged vac lines and/or intercooler coupler.

With that low of miles they may be the original vac lines and I would recommend replacing them with silicon hoses. ALSO, if you just purchased/aquired this car you should MOST DEFINATELY replace the oil, filter, fuel filter, spark plug wire, spark plugs and engine coolant...

zheka

sorry to leave this information blank, the vehicle being sitting in garage for 2 years not being driven.
i have replaced spark plugs and wires, oil changed. I drain and refilled coolant.

zheka

you know on intake manifold there is 2 nipples for hoses. 1 for blowoff valve and other just covered. i tested through 1 that was covered.

zheka

yes vehicle was parked! ....why asked?

zheka

hey guys, would you recommend to replace map sensor, 02 sensor, tps sensor? are they know to go bad on fd's? i mean i personally don't hear any vacuum leak noises. hoses do look original. I think i should replace them all.
do you all think its most likely vacuum leak type problem i have?

t-von

iTrader: (8)

Diag one thing at a time b4 you start tearing the engine apart blindingly trying to replace stuff. So even during heavy acceleration in 1st gear, your not seeing any boost at all? You need to do a 3rd gear boost pattern test so we can furthure help you. Start off in 3rd gear at 40mph. Floor it and watch the boost gauge rise. Note the max psi level. At around 4,500rpm's you should see a slight dip in boost as the transistion to the secondary turbo happens. This time note the psi during the dip then again when it goes back up. At this point the boost should stay level till 6,700rpm till with point it gradually falls back down. The pattern your looking for is 10-8-10. The primary turbo needs to make at least 8psi b4 anything else in the turbo charging system can be able perform properly.

pyro_racer_0016

if you do a vaccum test sitting you will never see boost because turbos are load dependent

KaiFD3S

iTrader: (37)

Congrats, but just as a precaution, when you get the car running right be aware when taking turns and mashing on the throtle at the same time as when that second turbo kicks in it will take you sideways...

Enjoy and be safe...Welcome to the world of the money pit...

FD WannaBe

Research as much as you can. enjoy the love hate relationship.

dgeesaman

iTrader: (7)

actually you should see 4 psi when revving hard in neutral.

nero1106

iTrader: (12)

Like everyone has said check for loose vacuum hoses, cracked or loose couplers, the vacuum check valves, and the hoses from the turbos also become loose over time. Also if you never change them I would change the 02 sensor and fuel filter. Have you put in fresh gas? Premium? How was the car running before?

zheka

i don't know how it ran before! i just registered and start drive it like 2 weeks ago! now the car just dies with a/c on when you approach to a dead stop. Rpm drops very low and it just dies (only happens when driving with a/c).

zheka

tnx for the late warning it does that even with engine not running right!

MakoRacing

iTrader: (12)

Dont listen to him, hes a party pooper

pyro_racer_0016

my twins never did that they would go to 0 no matter how hard i revved it