thejallenator

iTrader: (14)

...

satch

iTrader: (1)

Did you ever test the fuel pressure?

HAILERS

IF you really have spark and IF the timing is close to spot on and IF you want the ECU to deliver much less fuel during START.......depin pin 3B of the ECU (black/blue) wire in the small plug, bottom row, far right).

As noted in one of the threads I pasted earlier, if the ECU does not see the start signal on 3B, then the ECU does not use the internal start fuel map but instead uses the afm signal which will deliver I'd guess, about a third or less fuel in ms when the engine is trying to start. As an example instead of the injector staying open 20 ms it'll only stay open 9 ms or less during Start.

Pulling off the water thermosensors plug will do close to the same thing.......ECU defaults to 176*F which in turn means much less fuel delivered during START. Also means the engine Might run a bit too lean til the engine water temp gets up to the actual 176*F.

Or unplug the fuel pump and spray starter fluid into the intake snorkel for no more than three seconds then start the car. Repeat three or four times then reconnect the fuel pump. I did NOT say pull any EGI fuses. That is not the same thing as uplugging the fuel pump and spraying starter fluid for three seconds into the snorkel/air filter.

Unplugging 3B also works on HOT starting problems. The only down side is that when the weather turns cold as in below sixty degrees or less, then difficult starts happen again 'cause this time too little fuel is delivered.

thejallenator

iTrader: (14)

i will try to depin pin 3B and see what that does for me.

and no i havent checked the fuel pressure. i dont happen to have a fuel pressure tester..

satch

iTrader: (1)

If your pressure is too high then it stands to reason that the injectors would emit too much fuel when they are in the open position. Not sure it works that way but I thought I would throw it out there for others to confirm or deny.

HAILERS

That makes sense. Did not occur to me. Fixated on it being something else. Harbour Freight sells stuff at unbeliveable low prices ( can we say low labour costs?). Might buy the cheapest fuel pressure tester they sell and tee it into the fuel pressure line right at the engine hard line (b/t the filter and hardline on the engine). Should read approx 37-39 psi with key ON, engine OFF (that part should be easy). Then maybe just attach the gauge into the output line from the filter with key ON...........pressue should be approx 80 psi (see FSM for exact figure range) for deadhead pressure from the pump with nothing else in line.

Or a sticking fuel injector. Not my favorite thought. I've never had one and never sent any injectors out to the cleaned. Have bought new injectors in the past but that's it for me and injectors. I doubt this is your probem. My predjudice.

thejallenator

iTrader: (14)

ok so test it before and after the filter? will do. and as for injectors i doubt that is the issue. they were just serviced not too long ago.

satch

iTrader: (1)

After the filter and before the hard line and you'll need to tee in the gauge to get an accurate reading. Also, if your water faucet was working perfectly but you increased the water pressure to the house then the faucet would emit more water at say half open then when operating at a lower pressure. Make sense?

petek8103

Sounds like a fuel issue to me, I had a problem with my 87 TII,I had bad primary injectors it would dump fuel over night to he point it would actually come out the Exhaust, try taking out the EGI fuse and crank it over a few times. Then put it back in and try firing it up.

HAILERS

Tee'd into the fuel line coming off the filter will give you the pressure that the FPR is regulating the fuel to. IF you just connect the gauge to the line coming off the filter and no tee is installed, you'lll read the full output of the fuel pump. YOur really just interested in doing the tee thing so you can see what the fuel rail pressure is.......or if you will, what the injectors see as pressure.

Fuel runs continouously thru the fuel system and back to the tank. The pressure in the rails is determined by the FPR which is the LAST thing in the fuel rails. It holds the pressure required and dumps the rest back into the tank and it cycles thru over and over and over and over and....

thejallenator

iTrader: (14)

its beyond doing that. trust me.


ok i will do it with the tee. after looking it up online it looks like thats the only way to hook up the testers. so i will give tht a try and see what it says. but yes satch what you said makes perfect sense.

petek8103

If you remove the plugs do you have fuel coming out?

thejallenator

iTrader: (14)

yes. tons of it. i've already said that. and pulling the EGI fuse and turning it over does not help because as soon as i try to start it again it refloods.

thejallenator

iTrader: (14)

ok so i just read up on your hot start thread and seen its exactly what you told me to do and it mentioned something about when it gets cold out that this will not work. and here it gets damn cold in the winter.. now wouldnt it be smart to wire in a switch rather than just ridding the harness of the wire? of course have that switch tucked away since it'll only be flipped once a year. this seems like a better solution to me. what do you think?

incubuseva

iTrader: (13)

What exactly do you mean by your injectors were 'serviced'?

Did you put some snake oil into it that supposedly cleans them out? Because that's not good enough.


I had flooding problems with my old NA motor. I had them sent out to be flow tested + cleaned then the problem pretty much went away. That's the only real way to clean them out. Don't waste your time/money with snake oils.

thejallenator

iTrader: (14)

oh wow. thank you a billion HAILERS!!!!!!!! it started right up when i cut that wire. but once warmed up i had a little issuew with getting it to actually start again. i had to hold the little flap in the AFM and "choke" it to get it to start. but its like a whole new car just by cuttin that wire. it even idles at 750 now rather than 1000 rpms

thejallenator

iTrader: (14)

witchhunter thats what i mean by serviced. i wouldnt ever waste my money on tht junk in the stores,.

HAILERS

Depinning that wire should only effect STARTING and nothing else. The ECU has a START FUEL MAP and uses that internal fuel map during starting only and ignores the afm until the engine gets over 500 rpm. Fuel is determined by the afm for any other situation. Sorry you cut the wire instead of depinning it from the plug. Hope you left enough wire to resplice it in the future if needed.

If it idles better now............that's due to something other than depinning 3B.

The ECU only knows to use the internal start map when it sees the 12vdc signal on pin 3B, and that signal is only there if the key is HELD to START.

You might resplice the wire the next time the engine is hot and see if the problem still exists or not. Like with it respliced you could see if it'll start again or not without messing with the afm.

thejallenator

iTrader: (14)

well i already explained my reason to cut it rather than depin it. but it was only that one time i had to hold the flap. it seems to fire up now. now that this bug is done and outta the way time to move to the next one....