Severe flooding...injector stuck open?

[Dieselsj]

87 7.4 TBI. 7427 ecu. It has been running great. Made a trip to the dump today and on the way out it started stmbling and CEL came on. I pulled over and jumped the pound but no codes came up (just got code 12 over and over).

Started it and it stumbled and stalled again. I popped the hood to start looking and heard something boiling inside the air cleaner. I popped the lid and it was totally filled with fuel. I quickly opened the throttle to dump the fuel into the intake. I feel blessed that I didn't have a fire.

As I sit here waiting for the btow truck, I thought I'd start researching. Anyone ever have an injector stick open?

[ralmo94]

I haven't heard of that personally?
Could the leads have gotten messed up?
Did you hear them clicking?
I can always hear my tbi injectors clicking at idle.
Maybe O-rings?
I'm sure you will be able to tell when you get the throttle body apart?

[myburb]

It might be worthwhile to check the wire from the injectors to the computer for any possible shorts. If there is any short the injector will just run continuously.

[Dieselsj]

Got home and doing quick diagnosis. When I turned the key on 1st thing I noticed was fuel pump never shut off it just ran continuously. I plugged the injectors back in and passenger side injector just opened and dumped fuel. Put an ohm meter on it and it showed that there was a path to ground. Unplugged the ECU and no ground path at the injector so that indicated a problem with the ECU. I did notice that my moates adapter didn't appear to be plugged in all the way. I reseated the adapter and plugged everything back in and now it all appears to be working again. Fuel pump shuts off after prime and injector isn't dumping fuel. Going to change the oil before I fire it up because I seem to have gained a couple quarts.

[ralmo94]

I have had a few limp mode drives from unseated moates adapter

[tayto]

with a big block it will have a fuel pump module that will run the pump for 30 seconds vs 2 seconds. have you tried checking the resistance of the injectors?

[dave w]

87 7.4 TBI. 7427 ecu. It has been running great. Made a trip to the dump today and on the way out it started stmbling and CEL came on. I pulled over and jumped the pound but no codes came up (just got code 12 over and over).

Started it and it stumbled and stalled again. I popped the hood to start looking and heard something boiling inside the air cleaner. I popped the lid and it was totally filled with fuel. I quickly opened the throttle to dump the fuel into the intake. I feel blessed that I didn't have a fire.

As I sit here waiting for the btow truck, I thought I'd start researching. Anyone ever have an injector stick open?

Are you using a Moates.net G1 adapter with a low profile ZIF socket?

dave w

[myburb]

I can’t remember if I have low zif or not but I cut a piece of 1/2” thick foam, got some slightly longer screws, put the cover back on and screwed down enough to put a little tension on the chip. The truck has been bouncing around on rough roads for years like that.

[dave w]

I can’t remember if I have low zif or not but I cut a piece of 1/2” thick foam, got some slightly longer screws, put the cover back on and screwed down enough to put a little tension on the chip. The truck has been bouncing around on rough roads for years like that.

I can't think of a single instance when a factory memcal I reprogrammed caused fuel injector "weirdness". . . WEIRDNESS = No Codes with fuel flooded Throttle Body.

I've seen a few rare instances where a PROM Chip adapter was removed and a factory memcal was reprogrammed to " COMPLETELY KILL" fuel injector "weirdness".

RARE = not occurring very often

dave w

[stew86MCSS396]

Keeping in line with injector weirdness... Gonna keep this short...friends truck had a MSD installed and on cold starts it was fine but as it warmed up it started to run rich to the point the engine stalled. To get it started the owner would disconnect one injector (idk if clear flood would have netted same results) and reconnect it when it started but the same routine would ensue. After messing with it for more weekends then I care to admit, he suggested "this MSD can easily be bypassed..." After he removed the MSD out of the picture everything returned to normal.

[Dieselsj]

with a big block it will have a fuel pump module that will run the pump for 30 seconds vs 2 seconds. have you tried checking the resistance of the injectors?

I have that same schematic. I have yet to find a fuel pump module anywhere on the vehicle.

[Dieselsj]

Are you using a Moates.net G1 adapter with a low profile ZIF socket?

dave w

Yes on the G1 adapter, but using the S2 ZIF socket. I didn't have the PROM cover on the ECU and I just have it laying in the cavity where glove box is. The road out was rough and I must have just bounced it hard enough to loosen it up,

[dave w]

Yes on the G1 adapter, but using the S2 ZIF socket. I didn't have the PROM cover on the ECU and I just have it laying in the cavity where glove box is. The road out was rough and I must have just bounced it hard enough to loosen it up,

ZIF sockets are convenient during the tuning process. After the first and only "Injector Weirdness" instances I experienced, I've discontinued using a ZIF socket long term. After the tuning process is finished, I remove the ZIF Socket and install the chip directly into the G1 adapter. Another option for me is to reprogram the chip in the MEMCAL . . . just like factory.

dave w

[tayto]

have you tried timing it to see if it shuts off after 30 seconds? pehaps someone has bypassed and thats why it runs indefinitely. it will still run the pump without FWIW.

[Dieselsj]

ZIF sockets are convenient during the tuning process. After the first and only "Injector Weirdness" instances I experienced, I've discontinued using a ZIF socket long term. After the tuning process is finished, I remove the ZIF Socket and install the chip directly into the G1 adapter. Another option for me is to reprogram the chip in the MEMCAL . . . just like factory.

dave w

Yep the plan is to remove the ZIF when I'm done. Always just seems there is something to tweak in the tuning.