GM tbi stalling issues & poss weak ignition (76 cj7 jeep)

[Torxhead]

Jzak, have you changed out the tps? Some require adjustments also. From what I have seen just getting fuel into the throttle body can be a major issue. Like from setting up a externally mounted fuel pump and getting it to work correctly. Fuel injection can be quite a can of worms.

 

[76cj7chick]

Oh !

I rebuilt the used throttle body I got from another seller.... All looked good... However, the inlet fuel threads on the body DID appear to be mangled a bit.. BUT, I decided to try it anyways... Unfortunately, Even with thread tape the gas continued to drip out as I ran the vehicle... (Other than that, everything else seemed fine...)
I let the seller know about the issue today..
Is there ANYWAY I can fix the threads on the throttle body? As, I can't see anything else wrong with it... It runs smooth and drives nice....(I REALLY like the throttle body too!! BUT HATE that he didn't check the threads before sending!!!!!!!!!!!!!)

PLEASE HELP! . :dunno::dunno::dunno::barf::barf:


Just talked with seller. He said he's mailing out a replacement tomorrow.. I said just the top part of the tb..

 

[Torxhead]

Those are metric threads btw, and not pipe threads either. You might have to find a shop that works on those things for repair of damaged threads, and or a junkyard or dealer for the correct fittings.

 

[76cj7chick]

Those are metric threads btw, and not pipe threads either. You might have to find a shop that works on those things for repair of damaged threads, and or a junkyard or dealer for the correct fittings.

Hi Torxhead!

I emailed the seller and he said he'd send out a replacement tomorrow.. Really hope he will... I said I just needed the Top part, as everything else seems fine...

 

[GARGOYLEJEEPER]

Jzak, start a thread, and tell us what you have done to it so far, and we will help you.

76cj7chick, sorry about your luck, if you were closer I would fix it for you, but they are sending another. Like I said a rebuilt TBI should be a bolt on and go.

Now you need to buy a Chevy 4.3 Dizzy and mate the Presto bottom to the Delco top. Still trying to talk you out of the Ford Duraspark.

Glad to here it is running good. :rock:

 

[jzak]

Jzak, start a thread, and tell us what you have done to it so far, and we will help you.

76cj7chick, sorry about your luck, if you were closer I would fix it for you, but they are sending another. Like I said a rebuilt TBI should be a bolt on and go.

Now you need to buy a Chevy 4.3 Dizzy and mate the Presto bottom to the Delco top. Still trying to talk you out of the Ford Duraspark.

Glad to here it is running good. :rock:

Thanks for the suggestion. Just posted a new thread:

http://www.jeep-cj.com/forums/f2/howell-tbi-problems-23737/#post198548

 

[76cj7chick]

Well I got the v6 tb. Rebuilt it, slapped it on. Runs (better than the v8 tb) but I think it's too lean as it stumbles and acts like its going to die but doesn't... Or, like you all said the TPS and IAC needs adjusting.

Also, seem to have vacuum leaks... Can't seem to correct this issue.. (It all started with changing from the one barrel intake (married) to exhaust manifold.. Any suggestions on how to correct this issue? Should I use red loc-tite on bolts?

Anyone know which way to turn the IAC screw to INCREASE the fuel air mixure?
How am I to test and adjust the TPS?? (I have a multi-meter)

I think the ecm also doesn't like the fact that it can't control timing. "Gimp home mod" kinda sucks.... Kinda wish I didn't change it..

I'm currently putting relays and fuses in the CJ7 and will go back to the fuel pain soon..

Sorry for the time consuming issues I am having with my jeep.. I'm sure to you all these would be an easy fix.. Wish I could find someone locally to help as my brain power is Limited ..

 

[jzak]

Well I got the v6 tb. Rebuilt it, slapped it on. Runs (better than the v8 tb) but I think it's too lean as it stumbles and acts like its going to die but doesn't... Or, like you all said the TPS and IAC needs adjusting.

Also, seem to have vacuum leaks... Can't seem to correct this issue.. (It all started with changing from the one barrel intake (married) to exhaust manifold.. Any suggestions on how to correct this issue? Should I use red loc-tite on bolts?

Anyone know which way to turn the IAC screw to INCREASE the fuel air mixure?
How am I to test and adjust the TPS?? (I have a multi-meter)

I think the ecm also doesn't like the fact that it can't control timing. "Gimp home mod" kinda sucks.... Kinda wish I didn't change it..

I'm currently putting relays and fuses in the cj7 and will go back to the fuel pain soon..

Sorry for the time consuming issues I am having with my jeep.. I'm sure to you all these would be an easy fix.. Wish I could find someone locally to help as my brain power is limited..

Hi 76cj7chick! Sorry to hear about the rebuilt tbi still not running right. I just put in a rebuilt TBI in my CJ, and I noticed that they capped off the idle screw adjuster, so you couldn't access it. I was initially thinking about drilling out a hole, but I was lucky that I didn't have to make any changes to the idle speed. If you can, adjusting that screw on your tbi may help.

Also, I used to live in Seattle, and I would bring my CJ5 to Olympic 4x4 Supply in Snohomish regularly. Their hourly labor rate was usually half of what the mechanics in the city would charge. More importantly, their main focus is Jeeps, so they know how to work on carbs and tbi's. They also have a Jeep Junkyard with hundreds of totaled CJ's being parted out.

If you can get your CJ7 up to Snohomish, it maybe worth having a second pair of eyes take a look at it.

Have a Mac & Jack's beer, and a Red Mill burger on me!

 

[Torxhead]

Vacuum leaks can be found by spraying WD-40 on the suspected area and listening for an increase in idle. Are you familiar with how to adjust that idle air screw by jumping the ALDL connector and disconnecting the idle air controller connector? This is the way I have it in my Howell book. As I recall, the tps is supposed to put out around 5 volts, They are expensive also, I would suggest you look that up. It might be time to find a local repair shop to help you out.

 

[76cj7chick]

Hi 76cj7chick! Sorry to hear about the rebuilt tbi still not running right. I just put in a rebuilt TBI in my CJ, and I noticed that they capped off the idle screw adjuster, so you couldn't access it. I was initially thinking about drilling out a hole, but I was lucky that I didn't have to make any changes to the idle speed. If you can, adjusting that screw on your tbi may help.

Also, I used to live in Seattle, and I would bring my CJ5 to Olympic 4x4 Supply in Snohomish regularly. Their hourly labor rate was usually half of what the mechanics in the city would charge. More importantly, their main focus is Jeeps, so they know how to work on carbs and tbi's. They also have a Jeep Junkyard with hundreds of totaled CJ's being parted out.

If you can get your CJ7 up to Snohomish, it maybe worth having a second pair of eyes take a look at it.

Have a Mac & Jack's beer, and a Red Mill burger on me!

Hey jzak! Thanks for the heads up on olympic 4x4.. Didn't know they were a body shop.. When ever I went up there to look for parts I found myself "engrossed" in all the cool spare jeep parts...... But, just don't think my jeep would make it at the moment.. Probably since I built my cj...
-There jeep recycling junkyard is lots of fun to visit and check out all of the great parts.. Any words to the wise on how to get a Great deal on parts? Anyone I should speak to specifically, maybe??!!?

 

[76cj7chick]

Vacuum leaks can be found by spraying WD-40 on the suspected area and listening for an increase in idle. Are you familiar with how to adjust that idle air screw by jumping the ALDL connector and disconnecting the idle air controller connector? This is the way I have it in my Howell book. As I recall, the tps is supposed to put out around 5 volts, They are expensive also, I would suggest you look that up. It might be time to find a local repair shop to help you out.

Hi Torxhead.

Should I use throttle body cleaner spray or is WD40 better?

I have the instructions off line on how to adjust the Idle Air Control screw.. .Only it doesn't say which way will increase fuel and air mixture... (I know righty tighty and lefty loosey... But which way will increase mixture?)

So... For the TPS volts... Is that with key on, engine off? Or running or? with key off?

Not yet ready to take to a mechanic... Generally when they see a girl, they think to themselves... $$$....

And Thanks for chiming in...

 

[jzak]

Hey jzak! Thanks for the heads up on olympic 4x4.. Didn't know they were a body shop.. When ever I went up there to look for parts I found myself "engrossed" in all the cool spare jeep parts...... But, just don't think my jeep would make it at the moment.. Probably since I built my cj...
-There jeep recycling junkyard is lots of fun to visit and check out all of the great parts.. Any words to the wise on how to get a Great deal on parts? Anyone I should speak to specifically, maybe??!!?

Gotta love their CJ junkyard! I was able to get a OEM center console from a CJ7 , and a Dashboard off a CJ5 all for $40. When I first started going there, you could walk around the jeeps by yourself, and rip out whatever part you wanted. The guy behind the counter would then look at the part and say "that looks like $10!"

Now all the parts are inventoried with a pre-set price, and you have to be chaperoned around the junkyard by one of the guys working there. Really takes the fun out of it!

Wish I could give you a someone to talk to. I left Seattle back in 2011, so my memory is a little hazzy.

Just incase you reach your last straw on your CJ, you may want to make the effort to limp it over to Olympic 4x4. It's getting to be a really rare thing to find a mechanic who has any experience on older vehicles, let alone Jeeps! If there isn't a diagnostic connector on the vehicle, they don't know what to do. If you showed them a 4bbl Carburetor, their heads would probably explode!

Well, best of luck to you! It sounds like you're 90% there! I'm sure you'll work out those last few gremlins.

Btw: I was told by a couple people only to use throttle body cleaner. Carburetor and other cleaners could do damage. Don't know if it's true, but just putting it out there!

 

[GARGOYLEJEEPER]

First thing you need to seal vacuum leaks, that is your main problem, use Permatek Aviation Sealer, if gasket is not sealing.

The IAC can not over come a lean ratio, disconnect while running and nothing will change. To set, ignition off 10 seconds, start & run for 5 seconds, off for 10 seconds. There is no adjustment. To check you need a scan tool

Since you do not have a scan tool, probe Dk. Blue TPS wire w/ ignition on engine not running, should be less then 1.25 volts. If more then 1.25 volts replace TPS, since it is non adjustable & non repairable.

To set idle everything else should be checked and set and timing correct. Then you need a scan tool, to perform this operation.

Fix the vacuum.

 

[Torxhead]

Usually vacuum leaks with a tbi are at the mounting area. To find the source of the vacuum leak, all you need is something that will affect idle speed. Those tbi gaskets are expensive, so I just trace mine out on purchased gasket material and cut them with an x-acto knife. That idle air screw is just a stop screw for the throttle plates, it does have a weird adjustment procedure though. Hopefully your tps is good as they are expensive. I think mine was around $50. but it did help.

 

[76cj7chick]

Gotta love their CJ junkyard! I was able to get a OEM center console from a CJ7, and a Dashboard off a CJ5 all for $40. When I first started going there, you could walk around the jeeps by yourself, and rip out whatever part you wanted. The guy behind the counter would then look at the part and say "that looks like $10!"

Now all the parts are inventoried with a pre-set price, and you have to be chaperoned around the junkyard by one of the guys working there. Really takes the fun out of it!

Wish I could give you a someone to talk to. I left Seattle back in 2011, so my memory is a little hazzy.

Just incase you reach your last straw on your CJ, you may want to make the effort to limp it over to Olympic 4x4. It's getting to be a really rare thing to find a mechanic who has any experience on older vehicles, let alone Jeeps! If there isn't a diagnostic connector on the vehicle, they don't know what to do. If you showed them a 4bbl Carburetor, their heads would probably explode!

Well, best of luck to you! It sounds like you're 90% there! I'm sure you'll work out those last few gremlins.

Btw: I was told by a couple people only to use throttle body cleaner. Carburetor and other cleaners could do damage. Don't know if it's true, but just putting it out there!

Thanks for the encouraging words jzak! Everyone may be correct about the vacuum leak... Since I don't recall having such an issue with the one bbl carb.. (Eventhough the cast iron exhaust manifold had a crack and appeared the previous owner jp welded it.. But it didn't stay on..)

Good to know about the throttle body cleaner.. Don't want to cause more issues with my peep...

 

[76cj7chick]

First thing you need to seal vacuum leaks, that is your main problem, use Permatek Aviation Sealer, if gasket is not sealing.

The IAC can not over come a lean ratio, disconnect while running and nothing will change. To set, ignition off 10 seconds, start & run for 5 seconds, off for 10 seconds. There is no adjustment. To check you need a scan tool

Since you do not have a scan tool, probe Dk. Blue TPS wire w/ ignition on engine not running, should be less then 1.25 volts. If more then 1.25 volts replace TPS, since it is non adjustable & non repairable.

To set idle everything else should be checked and set and timing correct. Then you need a scan tool, to perform this operation.

Fix the vacuum.

Thanks for your suggestions GARGOYLEJEEPER!

By the way, I rechecked my spark plugs and four in the middle have carbon deposits, pretty bad.. Maybe that was the issue why it ran not so well? #1 and 6 were clean. Do you think something else is wrong or just because I keep starting and turning it off that it doesn't have time to burn?
Haven't started it since cleaning the plugs.. Need to get more ATF (did a new filter, tube and deep pan on the GM Turbo 400 and had a leak in the oil core line) When I checked the fluid level as the engine idled noticed it was pretty low...

I will definitely check to see if the engine idles any different with the IAC connector disconnected. Spray around the intake/throttle body with cleaner and check the TPS voltage..

THANKS!

PS.. My timing is correct, checked that and it was 8degrees btdc

 

[76cj7chick]

Usually vacuum leaks with a tbi are at the mounting area. To find the source of the vacuum leak, all you need is something that will affect idle speed. Those tbi gaskets are expensive, so I just trace mine out on purchased gasket material and cut them with an x-acto knife. That idle air screw is just a stop screw for the throttle plates, it does have a weird adjustment procedure though. Hopefully your tps is good as they are expensive. I think mine was around $50. but it did help.

Thanks torxhead for the idea to check the tbi mounting area...

Pulled my spark plugs and found the four in the middle carbon deposited pretty heavy.. 1 &6 clean.. I've been starting and turning off a LOT lately but hopefully there isn't any other issue... (I was starting and turning the jeep off a lot because I had issues with fuel leaks, tranny oil leaks... But those all look good now.. Just need to get him running properly.. )
I know I can remove my Idle Air screw cap and adjust the IAC... Looks like I may have to if cleaning the spark plugs don't help.. .We will see...

THANKS BUNCHES FOR YOUR HELP!!!!