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

[GARGOYLEJEEPER]

The Idle Air is the IAC computer controlled the idle screw is plugged at the factory. You got a rebuilt leave it alone, the only thing you changed was the pump. Change pump, you are thinking to much into it.
You got the relay right. Go with a Bosch brand or Hella.

Here are a few diagrams the first is the relays (I know this is a V8 but it was posted on this sight awhile back, and disregard all but the relays).
The second is a `76.
The third is Bosch relays all 9 you want S1
The fourth is the ECM, EST w/TFI coil (Accel).

The Accel is a TFI 12v. no resistor. GM Remote Mount Coil 1984-95 #140011 34 to 37% more energy then OE.
17 to 23% more voltage then OE.
:us:
Plus it will hook up to the Chevy/GM ECM harness.

To bad Chevy I6 didn`t have EST, because all you would have to do is change the dizzy gear (like DUI`s HEI did). But I would forget about the Duraspark and go with the AMC 258 i6 / 4.2l bottom and 4.3 top, but that's just me. (Dia.4)

 

[76cj7chick]

Thanks for your response GARGOYLEJEEPER... Sorry for being a pain.. Just still scared to work on mr. jeep.. But the crazy thing is.. I still continue to do so...

I will look into adjusting the fuel pressure regulator screw.. Perhaps, it is down to 9psi and is starving the jeep of fuel?

Also after shut off, I open the throttle plates and white smoke comes out.. (Like smoke from a match) Any ideas on why it has the "smoke"?

----Perhaps this will help to figure out why my jeep stalls?-----

I figured out more issues with the jeep... First the jeep starts up quickly but, will stall if I don't give it gas. Sometimes It backfires in the throttle body --especially when I rev it and then it comes down from revving.. My vacuum appears to be 16-17inches.. A little low??

Any ideas of what this all means?

I've read several things in my jeep manual.. It may be the timing is off, bad ignition somewhere (distributor, coil or module)...

I checked the timing (with the distributor advance hose capped off it was 6degrees BTDC.. With the dist., advance hose connected it was 8degrees BTDC.... According to Howell's efi install paperwork the timing is correct.. But don't know if I should put it at 8degrees BTDC with the distr., capped off?
or leave timing?..

Sorry again for being a pain and "blonde"... Please let me know what you think..

 

[Torxhead]

I would not be too concerend at this point about starving it for fuel, my AMC 258 i6 / 4.2l w/tbi seems to run fine at 9 psi. If you open your throttle plates just after shut down, that is just unburned fuel inside the intake manifold, a spark plug plug inspection should show if you are too lean or rich. Your backfiring sounds like an ignition issue, your initial ignition timing should be good at 6 deg., thats what mine seems to run fine with. The idle speed sounds like the real issue here, The idle speed will go up as you manually increase the timing, you could try that and go for a test drive, or use the method for increasing the idle speed. Hopefully your ignition was good to begin with and there is no ignition problem here, as it is an old system. Have you taken it out for a drive yet this would check for ignition ping, top end timing, and fuel mixture?

 

[GARGOYLEJEEPER]

Dye hair Pink and it will run.
I still say it is the ignition and computer not liking the Prestolite and the IAC tach, not being there to test is a pain, need to be on a scope to read ignition. Try turning in or out the idle while keeping it running. That will set your plates.
Was the IAC new or used on the rebuilt TBI unit? Need to find out why the tach looses signal. Had a bad IAC on mine and it would die at every stop sign.
Put in a new one and had to repair the seat.
I would still go get a 4.3 dizzy and mate the 2, before I went Duraspark.
Keep us informed.

 

[76cj7chick]

I decided to look further at my ebay "rebuilt" throttle body.. I looked up the numbers on the throttle body and it appears to be for a 350 v8 engine.. What??!? But I bought a 4.3 v6 throttle body... And I cleaned the top of the injectors off (I could only find one with gm part number..) Injector # GM5235342 *RPD 9219 GM*... Aren't the bore sizes in the throttle bodies bigger for v8 350 engines? If yes, will having a v8 throttle body cause my ecm to miscalculate ? In my novice thought, I would say yes... But I am not an expert...

Also, I took the fpr apart and it was full of corrosion and rust.. Doesn't look like he did anything to it! One of the injector's rubber seal was not tight, but hanging and fell off when I removed it from the pod. I have a bad feeling about the tb... But would this issue cause stalling, backfiring through throttle body and such?

I contacted the seller and he said that all tb units are the same... But the Internet says otherwise.. He then asked if I want another one.. I said I don't have more $... He hasn't responded yet... :dunno: Was I swindled? But he sounded so nice...

 

[76cj7chick]

Dye hair Pink and it will run.
I still say it is the ignition and computer not liking the Prestolite and the IAC tach, not being there to test is a pain, need to be on a scope to read ignition. Try turning in or out the idle while keeping it running. That will set your plates.
Was the IAC new or used on the rebuilt TBI unit? Need to find out why the tach looses signal. Had a bad IAC on mine and it would die at every stop sign.
Put in a new one and had to repair the seat.
I would still go get a 4.3 dizzy and mate the 2, before I went Duraspark.
Keep us informed.

That's funny Gargoylejeeper... Because I did have my hair pink for a while..

Probably too much for the ignition to handle then... I will keep my eyes open for a better coil.. Any suggestions on a canister coil that is full 12v electronic ignition? I bought a accel coil from an ebay seller but it was broken upon arrival.. The seller was quick to apologize and refund though. Plus, I don't know about accel coils now since I've read a lot of negative reviews..

Hummm.. I got the IAC separate off e-scam.. Is there a way to test it and make sure its good?

The tps was included with the throttle body... But now since I've learned that the throttle body number is for a v8 350 gm I'm thinking that could be part of the problem... Don't know if the seller will be willing to work with me even though he said I have a 1 year warranty.. And I haven't been able to drive it because of the issues.

 

[76cj7chick]

I would not be too concerend at this point about starving it for fuel, my AMC 258 i6 / 4.2l w/tbi seems to run fine at 9 psi. If you open your throttle plates just after shut down, that is just unburned fuel inside the intake manifold, a spark plug plug inspection should show if you are too lean or rich. Your backfiring sounds like an ignition issue, your initial ignition timing should be good at 6 deg., thats what mine seems to run fine with. The idle speed sounds like the real issue here, The idle speed will go up as you manually increase the timing, you could try that and go for a test drive, or use the method for increasing the idle speed. Hopefully your ignition was good to begin with and there is no ignition problem here, as it is an old system. Have you taken it out for a drive yet this would check for ignition ping, top end timing, and fuel mixture?

Hello Torxhead, thanks for the suggestions. Good reminder about the spark plugs..Although I don't know if I ran it long enough to show any issues.. Nevertheless, I will check my spark plugs tomorrow.
That is good to know that it is just unburned fuel in the intake.. Perhaps, it is also because one of the injectors rubber seal ring had swelled up and was falling off.. Not to mention the other issues I found with the "rebuild" Including finding out that the throttle body is for a v8 350 gm.. Unless, you think it shouldn't matter... But my thought are: I have a GM prom chip for 4.3 v6... So it must have a different calibrations for the injectors... Right? Or am I being too paranoid?

Thanks to know about the timing.. I can rest my mind on that one...:wasted:

Ummm... I drove my jeep just a little down the street and back because it was trying to stall out. Had to keep revving it to keep it alive.. but it would back fire some out of the throttle body when it came down from the rev...

So.. Two things that may be the issue.. Could be my ignition and screw setting... But what about the fact that it is a v8 350 throttle body and regulator?
TB number: 17087101 1598 JRA .. .Would this mean my regulator is wrong or does it stay at the same 12-15psi?
I checked the one Injector number that I can read and it's PN: GM5235342 *RPD... Would this be okay on my AMC 258 i6 / 4.2l ?

Can I adjust the idle mixture screw to accept the larger bored throttle body neck??

 

[GARGOYLEJEEPER]

You should send it back and also notify e-bay, and tell them if he won`t honor his sell, you have buyer protection. I know I have been selling on e-bay for awhile. A rebuilt TBI from a parts store should be @ $309.00

The TBI are the same 1 1/16" bore for 4.3, 5.0 and 5.7 but the 5.7 has bigger injectors. Your computer bin file is set for 4.3 not 5.7. No adjustments can change it, it is a chip inside the ECM.

Just the condition of what you described, tells me that is the problem.
I do not know the part numbers, you need to check at a parts store, or somewhere that has that info. I have 2 Jeep parts books 1981-1985 Vol. 1 & 2, and a 1981-1984 Vol. 1 & 2 that is missing pages and a little tore up. All the other Jeeps from 1946 on I have on PDF`s.

If you do not want Accel get a MSD blaster, Later you will need a dual plug coil since you are going to use your GM ECM harness.

Please send the TBI back, and have him send a rebuilt 4.3.

 

[76cj7chick]

You should send it back and also notify e-bay, and tell them if he won`t honor his sell, you have buyer protection. I know I have been selling on e-bay for awhile. A rebuilt TBI from a parts store should be @ $309.00

The TBI are the same 1 1/16" bore for 4.3, 5.0 and 5.7 but the 5.7 has bigger injectors. Your computer bin file is set for 4.3 not 5.7. No adjustments can change it, it is a chip inside the ECM.

Just the condition of what you described, tells me that is the problem.
I do not know the part numbers, you need to check at a parts store, or somewhere that has that info. I have 2 Jeep parts books 1981-1985 Vol. 1 & 2, and a 1981-1984 Vol. 1 & 2 that is missing pages and a little tore up. All the other Jeeps from 1946 on I have on PDF`s.

If you do not want Accel get a MSD blaster, Later you will need a dual plug coil since you are going to use your GM ECM harness.

Please send the TBI back, and have him send a rebuilt 4.3.

Hey Mr. GARGOYLEJEEPER, I went to a cousin's wedding this weekend so was busy..

However, was able to check all of my spark plugs and they look clean.. Except for a little gas and fuel smell.. --(If its running rich I didn't get any black smoke out of the tail pipe.. But maybe it has something to do with the "swelled" up oring on one of the injector) I also emailed the seller and told him that he sent me a throttle body for a v8 instead of a 4.3. He responded stating they are the same. I explained to him that through my research they have different bores such and he reluctantly said he will probably send a replacement today.. I haven't heard from him so I sent him another email. Still waiting to see if he is good on his 1 year replacement warranty that he listed in the ad.
If I don't hear from him soon I may see if ebay will step in but I don't know its been over the time to put in a case.

Thanks for your help everyone! I guess this is what a newb gets... At least I'm learning..

Since I don't know if he will honor his 1 year warranty, I will see if my rebuilding the upper throttle body (replacing the warn fpr gasket and installing a new injector oring will solve the issue.) Only thing is I may have to get new injectors and a new fpr.. --However, I did do some research on the one injector with gm part number and it is supposedly off of a 4.3 but at 17psi.. And the fuel pressure regulator is non-adjustable. I looks like it was tack-welded to the side of the housing -fpr housing that is. But not completely sure.

I never noticed how easy it was to rebuild a gm throttle body though... Carburetors are harder to rebuild.. At least in my opinion...

I'll let you all know if/when James will send me a replacement.. And when I get to drive my jeepjeep...

 

[76cj7chick]

I just received an email from the seller.. He said if it doesn't go out today it will tomorrow and that he has other people take care of all of the shipping now.
So, maybe I should wait for the replacement? Since I too have a feeling it is the TB that is causing my stalling, backfiring and poor idling...

 

[Torxhead]

How was your ignition prior to the tbi conversion? Like when you let off the pedal, did it backfire?

 

[GARGOYLEJEEPER]

Well, he should take care of it one way or the other. And if not e-bay should because the part you ordered is not what you received. I would never have stayed in business with doing things like that. I would not do any more with the TB, no fixing what should have been install & go.

I am still trying to talk you into grafting a 4.3 distributor onto a AMC 258 i6 / 4.2l .

I have been on the CJ2a Page, instead of here, trying to get some answers and helping the members there. This forum is more of a CJ5 & CJ7 forum and so I went there, for my `48, and may stop posting on my retro-mod rebuild. Already have someone wanting to buy one of my stainless steel parts I made. Have stuff for sale on Craig`s List, e-bay JeepOregon, and on the CJ2a Page. More to list when I get a new Postal Scale, @ 200 parts to sell or barter/trade.

Let me know what happens with the replacement TBI.

 

[cj7inthetwigs]

Tail end of discussion here, but noticed the word "ebay". If I may, any problem one may have on eBay remember this, PAYPAL always has final say so regardless of what ebay says. However, PAYPAL only gives you a time frame of I think 30 days (not sure) once tracking states item has been delivered . So if a seller is slightly crooked they can pull one over on you. Anytime you are iffy always open a complaint against the seller or buyer for that matter in order to save your own. Its just extra insurance one doesn't think they need until its too late. I have had ebay say one thing and swear it so only to hear a different tune once PAYPAL laid the hammer down. Basically ebay would equal parking lot security and PAYPAL equal Federal Marshalls . Good luck in everything running smoothly!

 

[76cj7chick]

Howdy Guys!

I thought I'd give you a update on how things are going with the tbi conversion...

I rebuilt the upper part of the v8 throttle body the first seller sent me (stating that v6 and v8 tb are same...I know now that this is incorrect..) After rebuilding the upper part installing a new fpr diaphram, new injector ring-- the JEEP RAN SMOOTH.. No popping through the tb.. No stalling BUT still ran poorly and smelt fuel on the spark plugs and in the manifold.. Smelt rich....

AND THEN------

I finally did get (2) YES! 2 replacement throttle bodies...
BUT --
I checked on-line their throttle body numbers and both come up as V8's again....

So, I informed the seller that he sent me 2 and if he wanted 1 back, he'd have to send me a pre-paid return shipping label... It's been almost a week and haven't gotten one. But he did say that things like that have been happening since he has other people do his shipping... Hummm interesting....

SO to STOP playing games.... I decided to by (crazy) Wild and went ahead and purchased a USED :wasted: v6 throttle body from another high marked ebay seller.. In his ad he stated which tb number I would get exactly.. SO, couldn't pass it up..
He shipped the TB quickly.. Also packaged it REALLY WELL... I just finished rebuilding it and will try to start tomorrow.. It looked pretty good, and it had a tight throttle spring, no cracks, just dirty and needed new gaskets..
But I haven't tested injectors since I have no way to.. But they are also correct for the v6.. The throttle body I "bid" on and won on ebay is number: 17089018 if anyone wonders.. I also was able to cross reference it to other throttle body numbers through a web search "rochester 17089018".....

I originally had the ecm main power wire hooked up to my ignition coil... But since have decided to install a RELAY for my fuel injection and ECM harness... If anyone knows how to wire a relay up for the ecm main power feed... Please let me know if this is correct or what I need to do to fix it BEFORE I start my peep...:grinjeep:
Here is how I so far wired the Relay:

85 -ground
86- 12v ignition source (I put it on the Ignition Coil + lead.. Please let me know if it's okay)
30- 12v Fused (5amp) -Should I go higher? directly to +/power on battery
87- To fuse then ECM power/accessory then fuel pump relay etc..



Thanks for all of your patience and help!

 

[Torxhead]

From the relays that I have seen usually the wiring hookup is printed on the housing. Not sure about your ignition source though, on my coil there is 12v to it on startup and 6v during the run cycle, but you have a different ignition though. A good power source would be from the starter relay on the battery side thru a fusible link. For a fuse to the computer, the later CJs use a 3 amp, but I think a 5 amp would be fine. Checking voltage to your computer and fuel pump is a good thing also. By the time you get it finished, you should be an authority on the tbi.

 

[76cj7chick]

From the relays that I have seen usually the wiring hookup is printed on the housing. Not sure about your ignition source though, on my coil there is 12v to it on startup and 6v during the run cycle, but you have a different ignition though. A good power source would be from the starter relay on the battery side thru a fusible link. For a fuse to the computer, the later CJs use a 3 amp, but I think a 5 amp would be fine. Checking voltage to your computer and fuel pump is a good thing also. By the time you get it finished, you should be an authority on the tbi.

Hi Torxhead!!!

Thanks for your response... I should have mentioned that I have the Prestolite ignition, so no balast resistor.. 12V during crank and run.

Q... Is the Starter Relay 12v constant?

:ty:

 

[GARGOYLEJEEPER]

I sent you the diagram and it is right, what you are doing is right.
#30 either starter solenoid + or battery +, 5a fuse is fine.
#86 where you have it unless you want to run clear back to your ignition switch.
On e-bay I just sent a American Bosch 6v Wiper to Luxenburg.
I am glad you got it straightened out, with them.
Keep us informed, can`t wait to read your dizzy post.

 

[Torxhead]

The starter relay on the battery side is constant 12v, which is at the post connected directly to the battery. On my CJ there are two fusible links on that post also, one to the alternator and the other to the ignition switch. The wire from the ignition switch to the ignition module is a good source for switched power. I knew that the prestolites came in the pre '78s, but I did not know it came w/o a ballast. Looking at a '77 schematic, I see that the hot line to the icm is spliced into the coil positive, So your switched power choice should work.

 

[76cj7chick]

Thanks everyone for your (continued) help on getting my peep back on the road...

I am going to start "him" up tomorrow and see how he runs... :madjeep:

 

[jzak]

Hello 76cj7chick!

Sorry about your problems, but it's good to hear i'm not the only one with GM TBI troubles. The previous owner installed a Howell TBI kit, and it's been troublesome from day one. The throttle response was horrible. If i put the gas peddle down to fast, the engine would just cut out. I had to lightly tap the peddle to get up to speed.

Over the past year, i've changed out just about every part of the original TBI kit, with the exception of the throttle body itself. I switched out the ECM, Fuel Filter/Pump, Vacuum hoses. I also throughly cleaned the throttle body, changed spark plugs/wires/coil/distributer, just just about anything i could think of that would affect performance. Doing all this has substantially improved throttle response, but it hasn't cured the problem.

I wish you the best of luck in getting yours fixed. Would love to hear how it works out!