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View Full Version : EZ EFI Problems: someone has to be able to help.....



dusterbd13
06-02-2011, 06:38 PM
ok, so i have yet to get this system running properly, even after MANY hours of fiddling, sending the ECU and handheld back in to FAST, and a bunch opf calls to their tech line.

car is 1968 hemi roadrunner. mild hydraulic roller, 14 inches manifold vacuum, single 4bbd aluminum dual plane intake, cast iron exhaust manifolds into 3 inch headpipes into 2 1/2 h-pipe to bumper. makes 550 HP on engine dyno. 727 torqueflite tranny, with proper stall converter for the cam. fuel pressure is 43PSI at idle, runs at a steady 175 degrees, timing is 10BTDC.
vacuum hose to the regulator plumbed to full manifold vacuum on passengers side

im having a multitude of issues from trhis thing, and cant seem to get any aswers.
only trouble code is inj duty cycle

what its doing:
randomly dying out
running richer and richer as it warms up
IAC not keeping motor running when put into gear
very difficult to start
very unstable idle, and wint idle below 1100 RPM

when the thing dies out sometimes, it seems to die out lean as it wont refire without being primed with ether. other times it fouls the plugs from running so rich.

thing i have tried to correct problem

1. adjust timing. was origonally too far advanced
2. rerouted the wiring harness so it was NOWHERE near the rest of the wiring, except for the battery leads, and the pink wire supplied to the back of the ignition switch
3. sealed the o2 bung with JB weld to make sure no air leaks
4. relearn the system repeatedly
5. double checked every connection and vcacuum cap
6. bumping the IAC counts to the bottom, middle, and top of the count range to keep it running
7. adjusting the idle target AFR to leaner and richer
8. sending the ECU and handheld back to FAST for a check over

i haven not yet been able to drive the car with this system, as it runs so poorly and erraticaly that i cant even get it out of the shop wothout it stalling.

what am i missing here? there has to be something im missing. something basic or simple.
im ready to get this thing done and back to enjoying my hobby.

Michael

SD455
06-02-2011, 08:06 PM
ok, so i have yet to get this system running properly, even after MANY hours of fiddling, sending the ECU and handheld back in to FAST, and a bunch opf calls to their tech line.

car is 1968 hemi roadrunner. mild hydraulic roller, 14 inches manifold vacuum, single 4bbd aluminum dual plane intake, cast iron exhaust manifolds into 3 inch headpipes into 2 1/2 h-pipe to bumper. makes 550 HP on engine dyno. 727 torqueflite tranny, with proper stall converter for the cam. fuel pressure is 43PSI at idle, runs at a steady 175 degrees, timing is 10BTDC.
vacuum hose to the regulator plumbed to full manifold vacuum on passengers side

im having a multitude of issues from trhis thing, and cant seem to get any aswers.
only trouble code is inj duty cycle

what its doing:
randomly dying out
running richer and richer as it warms up
IAC not keeping motor running when put into gear
very difficult to start
very unstable idle, and wint idle below 1100 RPM

when the thing dies out sometimes, it seems to die out lean as it wont refire without being primed with ether. other times it fouls the plugs from running so rich.

thing i have tried to correct problem

1. adjust timing. was origonally too far advanced
2. rerouted the wiring harness so it was NOWHERE near the rest of the wiring, except for the battery leads, and the pink wire supplied to the back of the ignition switch
3. sealed the o2 bung with JB weld to make sure no air leaks
4. relearn the system repeatedly
5. double checked every connection and vcacuum cap
6. bumping the IAC counts to the bottom, middle, and top of the count range to keep it running
7. adjusting the idle target AFR to leaner and richer
8. sending the ECU and handheld back to FAST for a check over

i haven not yet been able to drive the car with this system, as it runs so poorly and erraticaly that i cant even get it out of the shop wothout it stalling.

what am i missing here? there has to be something im missing. something basic or simple.
im ready to get this thing done and back to enjoying my hobby.

Michael

I am trying to remember,but I think the vacuum should be hooked up to the throttle body,above the throttle plates and not directly to the manifold. Where is the O2 sensor mounted? and have you checked to ensure it is not the problem? If there is any portion of the wiring that is suspect-re do it,and ensure that all grounds are rock solid. I spent about a week wiring mine,and soldered all connections,followed the instructions explicitly. If you rule out all these things,then it has to be the ecm,or?

Hope this helps!
B.

jtm311
06-03-2011, 06:35 AM
Question what are you using to tigger the tac input? From what I understand this signal is key.

John

milehigh69
06-03-2011, 11:50 AM
send it back for a new one or to make sure the one you have is working properly.

dusterbd13
06-03-2011, 05:59 PM
tach input is signalled with their RPM module off the negative side of the coil.

already sent it back, and they claimed it was fine.

pulled the trottle body down tonight to doubel check everything. came out good.

have an idea that the bulkhead connector for the ignition may be having some intermittant connection problems, so i will test that theory tomorrow.

any other ideas guys?

Michael

jtm311
06-03-2011, 06:16 PM
Michael,

I just finishing my install of the Fast EFI. I read so much about the tach input problems and ground problems, so I also purchased a MSD box which so many people recommend. I wanted to fist install the EFI system test it then do the MSD box. One other thought the module they give you to hook to the tach input I took both black wires right to the Battery Neg not to the block as quoted in the directions. After running it for a while like this yesterday I install the MSD today, I can tell you my results at idle are far better now that I installed the MSD box.

Just a thought.
Good luck

John

d69bird
06-03-2011, 06:20 PM
Try setting fuel pressure at 43# with the regulator vaccum disconnected and plug.

jtm311
06-06-2011, 03:20 AM
Michael any update?

John

David Pozzi
06-08-2011, 12:16 PM
A clean tach signal is a must. Connect direct to battery for power.
Are you using the FAST throttle body with their sensors?
After starting, monitor your sensor data to insure they are all working properly. The ECM won't know if a sensor is reading wrong unless it's completely dead. Does it ever go into learn mode? It should start & run decently even without having time to learn. It would have been good to send the throttle body & sensors along with the ECM to be tested.

There is a lead near the fuel pump relay you can ground to keep the pump on & set fuel pressure.

dusterbd13
06-08-2011, 12:22 PM
wound up finding a couple of problems, and getting it resolved.
1. intermittant ignition failure due to a bad wire
2. partially blocked IAC hole in the throttle body
3. trans a little too tight (automatic) for the IAC to compensate for when shifted from neutral to gear.

thanks for all the help, guys.

Michael

David Pozzi
06-08-2011, 05:09 PM
There is an air conditioning fast idle wire that can be connected to the shifter. It would boost idle speed when in gear plus it's adjustable with the handheld programmer. When 12v is applied, you get fast idle, its intended to be spliced into the air conditioning clutch wire. Connect your distributor vacuum advance to manifold constant vacuum, not ported.

73chally
06-20-2011, 03:31 PM
Im having the exact same symptoms you were having, with my 440 challenger. How did you get them resolved? I sent you a pm..thanks

A BAD SS
07-03-2015, 08:18 AM
Went out 2 fire up the Hot Rod last night, and it wouldn't start...At key on, FAST EZ EFI injectors dont fire for the "pre-squirt" procedure. Key turns on, engine turns over, but engine wont start. Any suggestions? Car had been running fine. ��
69 SS

Mr Nick
07-03-2015, 08:46 AM
Went out 2 fire up the Hot Rod last night, and it wouldn't start...At key on, FAST EZ EFI injectors dont fire for the "pre-squirt" procedure. Key turns on, engine turns over, but engine wont start. Any suggestions? Car had been running fine. ��
69 SS

First, I would start a new thread, you'll probably get more attention.

Second, is the coolant temp sensor hooked up as it should be? Is the sensor OK? I believe the "primer" function based on temperature. Meaning, if the engine is stone cold it will do full length primer squirt, but if it's at full operating temp it may not prime at all. Also, if the key has been cycled and engine primed once or twice, but never fired, it will NOT prime again. This is to prevent flooding. I found this out while turning to KEY ON a few times while working on wiring projects. When I started it next it had to crank for a while because the computer saw previous "prime" functions but never a complete start.

A BAD SS
09-28-2015, 10:36 AM
I had a new Viper alarm installed and thought that could be the culprit. Which after further investigation, the alarm tech hooked up the ignition wire to the fuel pump relay-so car would not start. Hard wired the yellow ignition wire for the alarm right to the fuse box. Problem solved. Just reading this thread again. Hope this helps future FAST EZ EFI users.