MFI replaced throttle body gasket, now no start!

[pszemia]

Hi everybody!

Last week i took 5 hours cleaning the throttle bodies and the intake pipes on my 73 2.4 MFI.

Before all the work, the car would start and idle rough, because i had to start the CMA again, but it started and idled more or less ok.

After replacing all the throttle bodies gaskets, and the pipe gaskets, i reassembled the throttle bodies, the intake pipes, the corss-shaft, and all the rods keeping the pump rod at 114mm.

I went to start the car, and no fire, tried again, and no fire.

I started with the standard procedure:
- checked for spark from HT lead at coil --> yes.
- checked for spark from spark plug cable --> yes
- checked fuel pump at fuel filter and working
- checked return line from MFI pump to fuel filter, and throwing fuel on it, lots of. so i assume the fuel pump is working quiet well.
- checked MFI belt, and it moves when the engine cranks.

So i think i have a problem with the fuel:


I removed all the fuel lines and then reasemble them (to remove the throttle bodies), so they are empty of fuel. Do i have to make any special procedure to fill them with fuel?

because i suspect i got no fire, because of lack of fuel at the injectors, and thus no engine start.

Also i removed the cyl 4 fuel line from MFI pump, to see what happens when i crank the engine, and i found that when i crank the engine, there is little fuel coming from the cyl 4 outlet at the MFI pump. It's like pumping fuel but it takes some crank time to overflow from the connection outlet.

I suspect this is too slow to fill the fuel lines, and also to low to make the injectors work.

But also, i have to say i haven't touch anything than changing the gaskets, and clean the throttle bodies.


any help with thiss???'

thanks a lot!!

Ariel

[jeffc280sl]

Read this post about purging air from fuel injector lines.

73 ignition + MFI problems HELP PLEASE !!!

[pszemia]

ahhh nice tip, i was cranking, cranking, cranking, and going nowhere, now i understand a little bit more from MFI pump.

i'll try today and post news here...

[pszemia]

Been 2 hours trying to start and nothing.

Tried the procedure for taking out the air from the fuel steel lines.

Removed the rubber tip to access the main rack and the hole is much bigger than M5, it's like M9. Also it doesn't have a form to screw the M5 bolt. I think i still have air in te lines, and i'll start freaking out how to remove it.

Need some help here, still don't know how to relive it.

Should i keep cranking till i get fire???

Thankss

[Zeke]

I would squirt some ether or other starting fluid to get the motor to run a little. You have the "in stack" primer lines, so doing this with the air box off should be somewhat safe. If it won't catch with starter fluid, you have another problem. Avoid using raw gasoline.

Keep an extinguisher nearby in case. Those stacks can spit back, so keep away. You really should be using a remote starter switch so you can be back there to see what is going on.

As I type this, I wonder if the cold start solenoid is working. There should be an abundance of fuel in the console if the fuel pump is working and you should have wet butterflys. What is the condition of the center fuse in the rear relay box? BTW, if you manage to flood the motor, remove that center fuse.

I don't think you can get a cold MFI motor to start very well w/o the cold start system working. I see it's only 5 to 15 degrees Celsius there.

[pszemia]

Milt, the cold start solenoid is working. I tried it with a bottle right from the tip, and there is plenty fuel coming, so it's working right

I think the problem is still the air, but cant take it off.

Thankss!

[pszemia]

still no luck .

the worst thing is i CAN'T ride my porsche, it's been a long time without riding it

any ideas??

[RSTarga]

does it start with starting fluid? Are you sure everything is connected? Is the hand throttle connected and are you pulling it up? Pull a spark plug and see if you have not flooded it. Are your points in the distributor properly set? Can you hear your CD box whine when you turn the key on? Lots of things to check.

[pszemia]

everything is well connected, i pulled up the hand throttle. I have beatiful spark and CDI working perfect. No points, just installed a new petronix.

haven't tried with starting fluid yet. How much should i put inside the throttle stacks? in all of them or just in some of them?

[Zeke]

Don't leave the ignition on with Pertronix. They burn up. check that spark again.

[pszemia]

milt, i know they burn up, when i left the ignition on and cranking, to fill fuel lines, was with the CDI and petronix disconected. i reconnected them when i started cranking, and cranking and i got around 1 explosion after 5/6 seconds cranking, and white smoke coming from the exhaust, and also when i open the throttles, i can see with a flashlight white smoke inside the chamber.

[Zeke]

I just read this from another thread:

Originally Posted by pszemia

well, i have just come back from working with the car, with some great news

Finally the problem was, the points. They where closing and opening, but somehow didn't work right, so i installed the petronix system i bought on my last trip to USA, and guess what?

Started like a champ!

there was a lot of old fuel round there, so i ran the car some minutes to clean it all the possible, with a liquy moly injection reinginier and some new fresh fuel.

I am very happy so far with the petronix the installation was very easy, and got it working very fast.

But i have one question about the dizzy.

I removed it at TDC and rotor pointing Cyl 1.

But after installed the petronix, i have to rotate the dizzy all the way right, to get the right timing.

Did i miss anything, or maybe the petronix is bad installed, or don't know if i installed the dizzy one notch further, and that's why it is at the end of the "timing adjustable area"?

thanksss alottt for the helpppp

I guess you have the distributor back in correctly? Did the car run before you removed the stacks?

[pszemia]

milt, yes it run before i removed the stacks, that's why i think the problem is air in the fuel. that no start condition, was because the points were burned up.

in that run, the dizzy was well installed, the problem was one little check i missed, it was not timing right becuase there was 2 cyl sparkplugs connectores dissconected (i think #2 and #6), and that's why i had to move the dizzy all that way :P

[jeffc280sl]

Sounds like your rack may be stuck. Access to check the rack is described in this post which includes pictures. Can you move the rack and does it spring back?

MFI pump not pumping at all?

[pszemia]

jeff, already checked it. Inserted a bolt and i can move the rack inside (let's say to the tail of the car), and it spring back when i remove the bolt.

i don't know how that post end (i rode it 12 times i think hahah), because he said a bend line, but will 1 bend line, obstruct fuel in all the others?? and also, how can you bend on of those steel lines?

[Zeke]

I think he had a bent line before the pump.

[jeffc280sl]

Is it possible for you to measure fuel output from the filter per the attached tests?

[pszemia]

Yes, i can do that test this weekend to see how much flow deliver in 30sec.

Also i can say, that i did kind of this test to check if fuel was being delivered to the MFI pump, and i think it was for 3, 4 seconds, and there was plenty of fuel coming from the MFI pump return line.

[herman maire]

pszemia,

I replied to you email. I did not read this post before replying so theres a few suggestions that you have already checked. I second what Milt suggested..... have a fire extinguisher at hand just incase, when checking for fuel and spark, bad things tend to happen very fast.

let me know.

[Bobboloo]

If you cleaned your throttle bodies then you need to recalibrate your setup because now your throttles will be passing more air so your air to fuel ratio is changed.

1. Verify that your getting fuel from all six lines by loosing them from the tops of the injectors.

2. Once fuel is verified then you need to reset your throttle bodies.

Did you also clean your air correction jets? If not you might as well do it before you start.

I like starting with the air correction jets open 2 full turns from closed. Then I use a synchrometer to adjust the throttle plate stops. After adjusting throttle plates I then use the air correction jets for minor adjustments.

Once you get your throttles done then you can adjust your fuel enrichment starting with the main rack that is accessed behind the 5mm bolt next to the shut-off solenoid and then you end with the idle screw adjustment.

You should read up as much as you can. I recommend "Adjusting MFI" article by Lee Rice to start with.
Pelican Technical Article: Mechanical Fuel Injection Information MFI