It's a riddle

jfiscus · 05-01-2007, 08:35 AM

Yous hould be able to run w/o the IAC, if it runs well till it's warm then there is a sensor that kicks in when its warm, possibly a crank sensor? Also, are you buying name brand sensors or AutoZone/Advance sensors. Sometimes the sell you bad/wrong "new" sensors at these stores & you pull your hair out cause it's a new sensor & replace everything else when the new part itself was bad from the store.

(Had a couple buddys spend over a grand to finally diagnose their supposedly new/good sensors were bad.)

Mike F · 05-01-2007, 06:03 PM

NO the GM TBI setup uses the IAC to maintain idle at all temperatures and conditions along with a dozen other modes of control at other RPMs.

GM TBI does not use a crank sensor, the motor has a distributor along with a ignition module that sends a signal to the ecm that takes it and looks at the operating condition and decides how much spark advance is needed and sends a signal back to the ignition module to trigger the coil like any older electronic ignition.

GM TBI only has temperature, oxygen, knock, MAP, TPS, and speed sensors.

I can program older GM TBI systems and have set them up to run other brands of motors such as the AMC V8.

sarge · 05-01-2007, 10:19 PM

Jacob , you need to take the Chero to MikeF and let him get that thing running for you .

MikeF are you one of the MV4W's ? and did you wire Shawn B.'s YJ ?

Sarge

Mike F · 05-02-2007, 05:05 PM

Quote:

Originally Posted by sarge

MikeF are you one of the MV4W's ? and did you wire Shawn B.'s YJ ?

Sarge

Yes and yes, I talked to you at the swap meet.

sarge · 05-02-2007, 08:57 PM

I thought so , Jacobs rig is my old one , it ran great with a quadrajunk on it so I know it's a FI problem. He sure could use some help on this one , and I really want to see the old girl on the trail. You rarely ever get to see your vehicle in action and not be behind the wheel.

Hybrid · 05-03-2007, 10:39 AM

Yes, I am out of ideas. i really want this thing running right! I have purchased all the sensors i replaced from NAPA. I have replased the ingnition coil in the distributor, the oxygen sensor (which now that I think about it, that one was from Autozone), and i replaced the knock sensor, which was from NAPA. Mike F. if you think you can fix it that would be great!! Send me your info and lets talk. Thanks so much for all the help so far!

Jacob

Mike F · 05-03-2007, 04:23 PM

What model ecm do you have? I just need the last 4 digits of the number. If they are 7747 I can program that one, if it is another number I may only be able to hook into it and see what is going on depending on year and model and what is left of the harness ;)

Ignition COIL in the distributor? If that is true it sounds like it is a car setup and a early one at that, what exactly do you have? We may have to go through it bit by bit to make sure it all matches somewhat.

05-01-2007, 06:03 PM	#2
Mike F EFI AMC 360 Join Date: Mar 2007 Location: New Lebanon, OH Posts: 32	NO the GM TBI setup uses the IAC to maintain idle at all temperatures and conditions along with a dozen other modes of control at other RPMs. GM TBI does not use a crank sensor, the motor has a distributor along with a ignition module that sends a signal to the ecm that takes it and looks at the operating condition and decides how much spark advance is needed and sends a signal back to the ignition module to trigger the coil like any older electronic ignition. GM TBI only has temperature, oxygen, knock, MAP, TPS, and speed sensors. I can program older GM TBI systems and have set them up to run other brands of motors such as the AMC V8. __________________ 89 YJ EFI AMC 360, T18a, D20, built D44, 14 bolt, 38" Creepy Crawlers.

05-03-2007, 04:23 PM	#7
Mike F EFI AMC 360 Join Date: Mar 2007 Location: New Lebanon, OH Posts: 32	What model ecm do you have? I just need the last 4 digits of the number. If they are 7747 I can program that one, if it is another number I may only be able to hook into it and see what is going on depending on year and model and what is left of the harness ;) Ignition COIL in the distributor? If that is true it sounds like it is a car setup and a early one at that, what exactly do you have? We may have to go through it bit by bit to make sure it all matches somewhat. __________________ 89 YJ EFI AMC 360, T18a, D20, built D44, 14 bolt, 38" Creepy Crawlers.

05-01-2007, 08:35 AM	#1
jfiscus Terrain Stomper Join Date: Feb 2007 Location: Crittenden, KY Posts: 633	Yous hould be able to run w/o the IAC, if it runs well till it's warm then there is a sensor that kicks in when its warm, possibly a crank sensor? Also, are you buying name brand sensors or AutoZone/Advance sensors. Sometimes the sell you bad/wrong "new" sensors at these stores & you pull your hair out cause it's a new sensor & replace everything else when the new part itself was bad from the store. (Had a couple buddys spend over a grand to finally diagnose their supposedly new/good sensors were bad.)

05-01-2007, 10:19 PM	#3
sarge Pure Bacon Join Date: Jan 2007 Location: Trenton, Oh Posts: 1,098	Jacob , you need to take the Chero to MikeF and let him get that thing running for you . MikeF are you one of the MV4W's ? and did you wire Shawn B.'s YJ ? Sarge

05-02-2007, 08:57 PM	#5
sarge Pure Bacon Join Date: Jan 2007 Location: Trenton, Oh Posts: 1,098	I thought so , Jacobs rig is my old one , it ran great with a quadrajunk on it so I know it's a FI problem. He sure could use some help on this one , and I really want to see the old girl on the trail. You rarely ever get to see your vehicle in action and not be behind the wheel.

05-03-2007, 10:39 AM	#6
Hybrid Join Date: Mar 2007 Location: Fairfield, OH Posts: 134	Yes, I am out of ideas. i really want this thing running right! I have purchased all the sensors i replaced from NAPA. I have replased the ingnition coil in the distributor, the oxygen sensor (which now that I think about it, that one was from Autozone), and i replaced the knock sensor, which was from NAPA. Mike F. if you think you can fix it that would be great!! Send me your info and lets talk. Thanks so much for all the help so far! Jacob