Toooo much fuel

jeep
gasoline

#1

1886 Jeep Cherokee 4 banger. The fuel injection system is feeding to much fuel. I’ve checked all the computer inputs and they check ok. It runs for a few seconds then fouls the plugs out black with soot. Any ideas?


#2

Have you considered replacing the injector? Perhaps after 122 years it’s not closing properly?


#3

too much fuel usually means either a faulty fuel input, or not enough air. possibly a 122 year old air filter needs changing too!


#4

or too much oats or hay


#5

perhaps we can use some parts from the 20002 Camry.


#6

All inputs check OK. some are go/no go, some are 0-5 vdc
I’m running open throttle body (no filter)


#7

The injector closes tight. When I run the fuel pump only there’s no leak by into the body.


#8

since it has a real carb, have you replaced the distributor cap? maybe you didn’t get the index correct?

was this running well before? what has happened to it since? what have you done to it, before, and since?


#9

related to the other recent post, possibly the auto choke is stuck on, thus the apparent fuel overload?


#10

what part of FUEL INJECTION don’t you understand? … a real carb. What’s that got to do with the distibutor anyway?
Geee let’s see … one day it ran and the next day it didn’t.


#11

Hmmmm … finally, a new idea. Tell me about the auto choke.


#12

Throttle Body Injection system doesn’t have a choke.


#13

How about the temp sensor input? If the ECM was seeing a constant temp of say… 20 degrees, it is going to have a very rich air fuel mixture. You should be able to check the resistance value of the sensor as it warms up to see if it changes.


#14

thank you but I’ve check and rechecked all the input sensors.


#15

question for all: How easily do catalytic converters clog? Would foul fuel clog it?


#16

Mb, that is tooooo funny! ha ha ha ha


#17

" Would foul fuel clog it?" Yes. Does this engine have a Map sensor? If so has that been tested?


#18

Check the fuel pressure. We’ve seen this problem with bad fuel pressure regulators. I had one Ford Bronco that was spittig black soot. The mechanical pressure gauge fluctuated between 20 psi and 110 psi. The idle also flutuated in time with the pressure fluctuations. A new pressure regulator fixed the problem.

BTW, the ODB-II system does not monitor the fuel pump or pressure, only feedback from the injectors.


#19

Change the injector. If it hust pops into the throttle body it probably only costs $80. I had a black spot behind the Tempo when I started it in the snow. The spot stopped happening when I got the new fuel injector. If you look at the injector when it’s working and you see any fuel dripping down the horn of the throttle bore, the injector is shooting a stream of fuel there. If you have a carburetor, never mind.


#20

What resistance did you read when you checked the Engine Coolant Temp Sensor?

This sounds like a textbook case of a failed CTS.