My car has been running really funky so we got down and finally did a test light on all the fuses. Discovered a blown fuse at TBI INJ 1 so we swapped it out, the car started ran fine and when we put in in drive it ran for about 30 sec and cut off, no sputter and die, just run and stop. Checked TBI INJ 1 again and the fuse was blown again. With the test light INST LP wouldn't light up at all. I'm guessing the INST LP is the ignition switch. If an aftermarket remote start was attached would it keep the INST from being hot? Does any one have an idea why I would blow the TBI INJ? I can assume there is a short or overload somewhere, but I don't even know where to start looking. Also I have no idea why the INST isn't lighting up, or even what that fuse spot is referring to. Any help is greatly appreciated.
86 2.8 GT
[This message has been edited by laoeser (edited 03-19-2011).]
Unplug 3 injectors Fuse uses. Blows fuse? Wiring has a short.
Check Ohm for Injector... All three should match. +/- a few of ohms is normal.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Ok inj 1 feeds bank 1 of the injectors only, inst lps is instrment panel lights. I would check to see if wires were tapped on these lines for the alarm, you can pull you fuse box down by removing 2-7mm screws and then squeeze two tabs on the side, the fuse box should drop down then you can do testing..... The wires in the fuse box are on top of the fuse that feeds them. so you can get an idea what wires to look at. INJ 1 is a pink wires, not sure about inst lps.. If there are wires for alarm tapped into any wires i would remove them, then test drive. If that doesnt solve your issue i would wait till you fix you issue before reconnecting them.
[This message has been edited by black88fiero (edited 03-19-2011).]
check ohm between terminal then terminal to ground... Should not be any ohms to ground.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Well we did some testing today to see what we could get. We tended to show 30 ohms in resistance across the injectors, but still can't find where, or if there is a short in the line somewhere. Pulled the plenum off and tested resistance in the plug in point of the injectors to the ecm and test from the ecm to the fuse box. Problem is not really sure what I am looking for (the wiring schematic in the service manual helps) or the interpretation of what I find. So needless to say it was a fruitless day and gremlin hunting.
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09:42 PM
phonedawgz Member
Posts: 17106 From: Green Bay, WI USA Registered: Dec 2009
INJ 1 runs the front bank AND supplies power to the EGR control solenoid. I'd really suspect that is the location of your problem.
INJ 2 is only the back bank.
The engine runs kinda crappy on only 3 injectors.
The reason you didn't get power on that fuse is because you had the light switch off. Turn it on and you should find power on both the in and out. I believe that fuse is actually past the dimmer also so make sure the dash lights are turned to full brightness to test.
The reason you didn't get power on that fuse is because you had the light switch off. Turn it on and you should find power on both the in and out. I believe that fuse is actually past the dimmer also so make sure the dash lights are turned to full brightness to test.
Yes... Inst LP mean Instrument Lamp. That fuse protects the transistor and only get power when parking lights and dimmer are on. See my came, dash dimmer in lighting section.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
in testing the egr solenoid to its plug in we got a reading when we tested the two wires leaving the plug in, they showed a reading on each single wire going into the solenoid. meaning the plug was giving us a reading from its two lines to both lines on the solenoid. makes us think the solenoids switch is stuck causing the short. any ideas before i go ordering a $100 part?
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01:51 PM
phonedawgz Member
Posts: 17106 From: Green Bay, WI USA Registered: Dec 2009
with the solenoid unplugged it ran and i ran it through the gears but immediately when i put it back in park it died, checked the fuse and it was blown again. Might this be the park/neutral switch? or does it still look like the egr not disengaging when you put the gear back into neutral?
Looking at the haynes repair manual wiring diagrams it has the upshift indicator light running with a switch to the injection system. this makes it seem like it is the park neutral switch. This is just a big pain in the rear chasing electrical gremlins all over the car.
This is the link to the problems that knocked the car out of commission a year ago and why it has been sitting since and not running correctly. We were not really ever able to solve what has caused this all along. just now discovering the blown fuse on top of previous things.
Well i keep adding stuff to this, now the car won't start at all and in just cranking the car over the fuse is blowing every time. the problem is getting worse it seems
[This message has been edited by laoeser (edited 03-20-2011).]
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03:21 PM
PFF
System Bot
phonedawgz Member
Posts: 17106 From: Green Bay, WI USA Registered: Dec 2009
Well that's good that it is blowing all the time. That way you can identify it quicker what is happening. There is a large flat connector near the thermostat housing. The power wire for the injectors run through that connector. So if you unplug that connector and crank the engine does the fuse still blow? At the ECM there are two connectors that connect the engine harness to the body harness. The power wire runs through that also. So if the fuse still blows with the thermostat connector unplugged then try that one. It's under the console. Do you see any damage to the engine harness wiring?
Since you have an automatic there is no shift indicator light. I believe the only things on the INJ1 fuse are the front bank and the EGR system.
btw, no the engine won't start with the wires unplugged.
[This message has been edited by phonedawgz (edited 03-20-2011).]
Well no change in the status of the fiero as of yet. I won't be able to work on it until the weekends with class all week. Hopefully there might be a few more suggestions to pass along. Any ideas are gladly taken!
Well looks like we got it up and running. Best we can tell it was corrosion on one of the plugs completing a circuit where it shouldn't have been. Many thanks for all the replies.
It seems that this is becoming a popular issue....my 88GT blew a TBI fuse on the way home from work...tg i found that it was merely a fuse...replaced the fuse, all was well again...until this morning of course. Fuse #2 blew. Pulled off the side of the road...and all i had was a 10A...so at least i could get to work...but im gonna have to get some fuses at lunch today.
Anyway, she bucked once, maybe twice the rest of the way to work but didn't blow the 10A fuse....so my guess is, if the 5A were in there, i would have gone through another 2 fuses.
Where did you find the corrosion? I am going to have to do some gremlin hunting myself tomorrow =/
Dan
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10:15 AM
phonedawgz Member
Posts: 17106 From: Green Bay, WI USA Registered: Dec 2009
The INJ1 fuse runs both one bank of injectors AND the EGR conrol valve. If that is the fuse that is blowing look at the EGR control valve also.
Not to bring up and old thread but ive been experiencing the same issues pretty recently only it is the TBI 2 that keeps popping. The thing is, you stated that it is the TBI 1 that also controls the EGR valve, however, all the schematics say different. At least from what i can tell, it is the TBI INJ 2 that controls the EGR. Am I correct in this assumption? Either way, I am going to go ahead and poke around after work and see if maybe there is an issue there. Although, like the gentleman above, I am not really sure what i am looking for =/ I will measure the injectors as well.
