car wont start!!!

johnson · 01-16-2009

1991 fwd turbo 5 speed

what does the boost gauge represent before car starts?
this is the stock boost gauge...
when its reading zero or positive, while cranking, it will fire in the engine?
when it reads negative when cranking, no fire at all?

does anyone have this problem?
what is it?

mpi relay also clicks right away then boost gauge is all the way negative?

i replaced coolant temp sensor with another one already, not new...

hippiekiller · 01-16-2009

Try a bottle of heet. Fuel lines are probably frozen.

johnson · 01-16-2009

it sounds and feels more electrical than anything else? i just dont understand the boost gauge reading?

**scheides** · 01-16-2009

The stock boost gauge is more of an airflow meter than anything, it does not correlate directly to boost at all.

**Shane@DBPerformance** · 01-16-2009

The boost gauge reading is some useless value calculated by the ECU. Probably calcaluted hz from the MAS or the load it uses for table lookup. It doesn't have anything directly to do with real vacuum or boost. Does it have any CELs? Could be a bad ECU, loose wire, or sensor problem.

johnson · 01-16-2009

well the ecu is more than likely good, its a rebuilt eprom ecu... and i think this is the same problem ive been having this whole time... i first tought ecu, it wasnt, then mpi relay, it wasnt, coolant temp, fuel pump but it works when it wants to and its not working today?

well i do have it hooked up to a jump car?
but i dont think that should make the boost gauge go wild like that?
could it be a bad MAS?

and the check engine does come on but it goes off after like 5 secs or so....
mmcd doesnt even read the light?

**Shane@DBPerformance** · 01-16-2009

It's normal for it to come on and then turn off like that hwen starting the car.

brando · 01-16-2009

i would check voltage at the mas. also try finding a good mass and see if that fixes it. it could also be bad wiring to your fuel pump.

johnson · 01-16-2009

im gonna try to start it tomorrow when its warmer... i dont know why the boost gauge is doin what it does but im thinkin it has a lot to do with why my car didnt want to start...

Kevin 1G Drummer · 01-17-2009

The stock boost gauge is about as usefull as tits on a bull. So unless there's some issue with your MAS, I wouldn't worry about what it reads.

GREASEMONKEY · 01-17-2009

Are you sure its getting fuel at startup? This kinda sounds like the same problem i was having. I also replaced the CTS, Swapped Injectors, Checked ECU, ETC.. I never did figure out the problem but i was thinking about the MAS being the problem.

This also only happened when it was really cold out, Eventually i could get it running but i had to pull the plugs and pour a little gas down the cylinders and it would fire right up.

Start out by finding out whats the main issue IE: Fuel, Spark, Air Intake / Vacuum leaks. Then it might be a little easier to narrow it down.

-Stephan

johnson · 01-17-2009

that bastard started up the first try today!
weak battery and all!
what a bi*ch!
i will probably try to switch out the mas for another one i have....
so i am honestly lost at this point!
thanks though!

i guess when its below 0 degrees? gotta jump in the toyota instead!

brando · 01-17-2009

also try replacing the o2 sensor. i had that problem and mine did the same thing yours is doing

johnson · 02-09-2009

the boost gauge is a big part of the car not starting.... now that it has warmed up, the car seems to not want to start again. again it will start whenever the boost gauge comes up to the zero, but if the boost gauge stays negative, the fuel relay will click right when i turn the ignition? and no fuel is what im guessing? my datalogger lost the mmcd program and i cant seem to find it online or have the know how of installing it back onto the pda? so i cant run the check engine light?

but as i said when the boost gauge is all the way negative the check engine light is on in the "on" position in the ignition....

but when the boost gauge is zero, the engine fires up right away, then kills, while it kills the fuel relay clicks?

johnson · 02-09-2009

i will try to get some vids posted soon..... i dont understand the boost gauge?

or if anyone has a logger that wants to swing by and give me a hand? i have some ice cold brew!

johnson · 02-10-2009

watch the boost gauge.....
comes up to almost zero but when cranking it goes negative.... doesnt start then just goes all the way negative...

http://s135.photobucket.com/albums/q...t=MVI_1219.flv

johnson · 02-10-2009

as again the next try...
boost gauge at zero... this time cranking, boost gauge is positive..... car starts....

but it eventually dies and does the same thing as before, boost gauge goes all the way negative and check engine light comes on.....

http://s135.photobucket.com/albums/q...t=MVI_1220.flv

iceminion · 02-10-2009

well, when the car "started" how did it run? and how long? was it running well, or really choppy?

My car has similiar issues, I have no clue what it is, but I am switching over to a standalone system, so it doesn't matter anymore

johnson · 02-10-2009

it runs perfect when its running..... somedays it goes all day, and others not even for a minute?

Kevin 1G Drummer · 02-11-2009

Sounds like an ECU problem to me.