sodrifter

iTrader: (4)

okay... please help! jus bought an 87 fc turbo with a fresh pineapple rebuild. car ran fine. drove it for about 700 miles and then sat for about 2 years. was started up every few weeks and warmed to temp the entire time it sat. drove up and down the road. boosted. no prob felt great. all the sudden it wont stay running. starts dies starts dies. unplug the maf and it runs for about 10 seconds instead of 1. plug it back in and back to 1 second run time. put a smoke machine on it and fixed a few leaks. no more smoke. it was coming out the tailpipes and nowhere in the engine bay. put a aem fuel pressure reg. on it and set it to 40psi. also has a walboro 255lph fuel pump. so i doubt its the fuel pump.

so basically it runs 5 times longer with the maf unhooked.

PLEASE HELP!!!!!!

misterstyx69

iTrader: (142)

Check the flapper on the AFM to see if it will move freely.
The last car I got was stored 2 years and the AFM was corroded and I had to disassemble the AFM and clean the flapper as it was stuck and wouldn't move.

dkwasherexd

iTrader: (8)

first things first, do a compression test. 95psi or greater is good !

If that checks off, verify spark, and fuel. If your getting fuel pressure, and spark and still not starting,spray some starter fluid to see if it fires up, if it does, it could be the injectors not spraying, stuck, or dripping[flooding]. I send my injectors to RC engineering , cost $25 per injectors to get services

or it could be the maff getting stuck as mentioned above..

sodrifter

iTrader: (4)

compression is fine has spark and fuel. does the same thing with starting fluid. also the injectors were sent out to RC and reinstalled already. maf has been replaced with another used one. still the same.

could i possibly have gotten another bad maf?
would the map sensor have anything to do with it?

Tofuball

Sounds like the car is dying at changeover. (When the ECU switches from the startup procedure to running condition)

There are tons of reasons this could happen, anything from one of the mandatory sensors being WAY out of whack (IAT, Coolant temp, AFM) and possibly even a wild signal from something else. I've seen a few S4s with a corroded sensor ground on the engine do something similar.

funkjaw

iTrader: (3)

Can you give it some gas and keep it running at say 2500rpm or above?

Tofuball

I just remembered a huge vac leak can cause this too. You say you smoked it, but how about holding your flapper door on the AFM slightly open and then starting it?

It might shut off the fuel if it's totally shut IIRC.

sodrifter

iTrader: (4)

i will try holding the flapper open a lil and see what happens. as far as giving it pedal. it makes no difference when the afm is plugged in when its unplugged however u can feather the throttle a bit.

funkjaw

iTrader: (3)

If it stays running if you keep it above 3000 rpm or so, chances are it is just a giant vacuum leak causing it not to be able to stay idling.

brian_skotch

iTrader: (6)

check the maf. my car was doing the same thing. Switched them out and it idles perfect now.

sodrifter

iTrader: (4)

ive switched the maf out for another. same thing

@ funkjaw
it doesnt respond to pedal at all when the maf is plugged in. only when its unplugged does it try to stay running.

sodrifter

iTrader: (4)

so now i got nothing. not even dash lights and i found rat **** all over the engine bay. little bastards! think i might have to swap harnesses? anyone done it?

sodrifter

iTrader: (4)

so i cleaned up all the wiring and put the car back together and now the starter seems to be ****. getting another one in the am. anyways... how much fuel pressure should i have? i have a walboro 255lph fuel pump. a mild streetport pineapple engine and a bnr stage 1 turbo. stock injectors.

jus wondering what i should set my pressure at?

sodrifter

iTrader: (4)

well... i got it back together and it still does the same thing. starts and dies. tried a different ecu. same thing. this is driving me crazy! i wanna drive it!

satch

iTrader: (1)

Jumper the fuel check connector. If that doesn't improve things then jumper the solid Black wire in the circuit Opening relay to the Brown wire in the same relay.

sodrifter

iTrader: (4)

where is the circuit opening relay?

sodrifter

iTrader: (4)

and what color are the wires coming out of the fuel check connector?

satch

iTrader: (1)

The two wires in the check connector are Black and Brown and the plug is Yellow but likely covered in a Black rubber boot.

The relay is Black and Yellow and located just to the right of the steering column just under the dash.

EDIT: And the check connector is located in the same harness that supplies the wires to the Boost sensor and is located fairly close to it.

sodrifter

iTrader: (4)

when i jumper the check connector it starts up easier but still dies. with the relay jump do i pull the plug and jumper the two connectors? (tried that no difference) or does the relay have to be plugged in when i jump the wires?

satch

iTrader: (1)

The relay needs to be plugged in. Solid Black wire (not Black/White) to Brown wire.

sodrifter

iTrader: (4)

jumped it with the relay plugged in and could rev it a bit whats the problem part?

satch

iTrader: (1)

So it runs longer and you could rev it, but it still dies out. Correct? And how high can you rev it to?

EDIT: With key to on and the TPS plug disconnected what is the voltage reading on the Brown wire? Should be 5 volts.

sodrifter

iTrader: (4)

i could rev it all the way. heard the turbo spool and the bov for the first time
and yes it still died

satch

iTrader: (1)

First check the Brown wire voltage as suggested.

EDIT: Also remove the jumper at the check connector but leave the one at the relay alone.

Also, w/key to on measure the Black wire at the check connector as it should read 0 volts as it is a ground. Make sure the jumper at this connector is removed.

sodrifter

iTrader: (4)

ok... everything is like u said. 5 volts at tps brown wire. 0 at check connector ground.

now what?