Tbi, again! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cfan10 · 10-30-2018, 12:37 PM

Is this a normal thing to have some sort of liquid copper on the distributor under the icm plate? Are pickup coils in these tbi distributors supposed to look so rusty...the plastic prong was broken of the tab that plugs into the icm from the pick up coil. The wires were crossed, the green was connected where the white should've been I know this because of a YouTube video.

New parts this year:
Belt
Plugs
Wires
Alternator
Battery
Fuel pumps X3
Coil
Fuel hoses
Fuel lines cleaned
Still only starts with starter fluid...runs a second then cuts cut.

Info
1990 5.7 tbi suburban engine/trans in a 1991 suburban lol
Does anyone sell a new stock tbi wiring harness?

As always help is sincerely appreciated!

cfan10 · 10-30-2018, 12:40 PM

Trying to post photos but this site is giving me issues.

daddyjeep · 10-30-2018, 12:55 PM

This was my first thought, but i'm sure there are other sources.

https://howellefi.com/product-catego...-tbi-products/

44th Miss Inf · 10-31-2018, 04:41 AM

If you can post a picture (or send to virgilroberts (at) hotmail.com) of the plug, I may be able help as I have 2 tbi harnesses that I use for the connectors

cfan10 · 11-05-2018, 07:54 AM

The wiring I'm talking about is inside the distributor, the pickup coil wire connection that goes into the icm. The wires were crossed.

**Palf70Step** · 11-05-2018, 09:18 AM

I do not think I have ever seen the inside of a dist look so rusty unless it has been sitting in a junkyard.

cfan10 · 11-05-2018, 07:26 PM

On the plate the icm sits on isn't rust it's copper paste that was under the icm.lol

Ofnaman1 · 11-05-2018, 07:55 PM

That distributor looks like its toast. The pickup is really nasty and is that corrosion on the terminals of the ignition module? The stuff under the ignition module looks like it may be anti seize. I think I'd start with a new distributor and ignition module. The ignition module controls the fuel pump and ignition system, and the pickup tells it when to do that. Usually when we get them in the shop like that I always recommend a new pickup coil and ignition module to start with (usually cheaper to just get a distributor assembly), as they can screw with multiple systems.

**hatzie** · 11-05-2018, 10:20 PM

Looks like someone used some kind of hot rod copper CPU grease as heatsink paste. Copper is conductive so if it gets in the wrong place it'll screw things up. I'd wipe it off and replace it with regular white Zinc-Oxide heat transfer paste. A 20oz tub of MG-Chemicals 860-60G is a lifetime supply.

The pickup coil generates a low level AC signal so polarity is not an issue. That's why it's not keyed. Plug it in any direction you want.

I'd clean it up and check the output of the pickup coil with an oscilloscope.

If you get a replacement be careful that it isn't one of the Chinese knockoffs that don't work.

10-30-2018, 12:37 PM	#1
cfan10 Registered User Join Date: May 2011 Location: Texas Posts: 984	Tbi, again! Is this a normal thing to have some sort of liquid copper on the distributor under the icm plate? Are pickup coils in these tbi distributors supposed to look so rusty...the plastic prong was broken of the tab that plugs into the icm from the pick up coil. The wires were crossed, the green was connected where the white should've been I know this because of a YouTube video. New parts this year: Belt Plugs Wires Alternator Battery Fuel pumps X3 Coil Fuel hoses Fuel lines cleaned Still only starts with starter fluid...runs a second then cuts cut. Info 1990 5.7 tbi suburban engine/trans in a 1991 suburban lol Does anyone sell a new stock tbi wiring harness? As always help is sincerely appreciated! __________________ Rest In Peace:Mikhail {Mickey Rooney} Alpha 2/5/13 Omega 7/22/14 10:28AM I love you tremendously and outragiously Superpuppi Thai Ridgeback...The most intelligent dog known to me. Don't mess with my truck, my momma or my money...not necessarily in that order. © Stand for something or fall for anything. [LIST][*]'98 Bourbon St. Brawl ©2010

10-30-2018, 12:40 PM	#2
cfan10 Registered User Join Date: May 2011 Location: Texas Posts: 984	Re: Tbi, again! Trying to post photos but this site is giving me issues. __________________ Rest In Peace:Mikhail {Mickey Rooney} Alpha 2/5/13 Omega 7/22/14 10:28AM I love you tremendously and outragiously Superpuppi Thai Ridgeback...The most intelligent dog known to me. Don't mess with my truck, my momma or my money...not necessarily in that order. © Stand for something or fall for anything. [LIST][*]'98 Bourbon St. Brawl ©2010

10-30-2018, 12:55 PM	#3
daddyjeep Registered User Join Date: Nov 2015 Location: Smethport, PA Posts: 1,213	Re: Tbi, again! This was my first thought, but i'm sure there are other sources. https://howellefi.com/product-catego...-tbi-products/ __________________ 85 K30 crew cab dually - Project http://67-72chevytrucks.com/vboard/s...d.php?t=694939 87 Wrangler Rock Crawler - Reason for the project http://www.wranglerforum.com/f330/da...ld-122601.html 04 1500 crew cab http://67-72chevytrucks.com/vboard/s...d.php?t=786514

10-31-2018, 04:41 AM	#4
44th Miss Inf Registered User Join Date: Sep 2002 Location: Liberty, Mississippi Posts: 672	Re: Tbi, again! If you can post a picture (or send to virgilroberts (at) hotmail.com) of the plug, I may be able help as I have 2 tbi harnesses that I use for the connectors

11-05-2018, 07:54 AM	#5
cfan10 Registered User Join Date: May 2011 Location: Texas Posts: 984	Re: Tbi, again! The wiring I'm talking about is inside the distributor, the pickup coil wire connection that goes into the icm. The wires were crossed. Attached Images __________________ Rest In Peace:Mikhail {Mickey Rooney} Alpha 2/5/13 Omega 7/22/14 10:28AM I love you tremendously and outragiously Superpuppi Thai Ridgeback...The most intelligent dog known to me. Don't mess with my truck, my momma or my money...not necessarily in that order. © Stand for something or fall for anything. [LIST][*]'98 Bourbon St. Brawl ©2010

11-05-2018, 09:18 AM	#6
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,223	Re: Tbi, again! I do not think I have ever seen the inside of a dist look so rusty unless it has been sitting in a junkyard. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

11-05-2018, 07:26 PM	#7
cfan10 Registered User Join Date: May 2011 Location: Texas Posts: 984	Re: Tbi, again! On the plate the icm sits on isn't rust it's copper paste that was under the icm.lol __________________ Rest In Peace:Mikhail {Mickey Rooney} Alpha 2/5/13 Omega 7/22/14 10:28AM I love you tremendously and outragiously Superpuppi Thai Ridgeback...The most intelligent dog known to me. Don't mess with my truck, my momma or my money...not necessarily in that order. © Stand for something or fall for anything. [LIST][*]'98 Bourbon St. Brawl ©2010

11-05-2018, 07:55 PM	#8
Ofnaman1 Registered User Join Date: Sep 2018 Location: Reno Posts: 58	Re: Tbi, again! That distributor looks like its toast. The pickup is really nasty and is that corrosion on the terminals of the ignition module? The stuff under the ignition module looks like it may be anti seize. I think I'd start with a new distributor and ignition module. The ignition module controls the fuel pump and ignition system, and the pickup tells it when to do that. Usually when we get them in the shop like that I always recommend a new pickup coil and ignition module to start with (usually cheaper to just get a distributor assembly), as they can screw with multiple systems.

11-05-2018, 10:20 PM	#9
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: Tbi, again! Looks like someone used some kind of hot rod copper CPU grease as heatsink paste. Copper is conductive so if it gets in the wrong place it'll screw things up. I'd wipe it off and replace it with regular white Zinc-Oxide heat transfer paste. A 20oz tub of MG-Chemicals 860-60G is a lifetime supply. The pickup coil generates a low level AC signal so polarity is not an issue. That's why it's not keyed. Plug it in any direction you want. I'd clean it up and check the output of the pickup coil with an oscilloscope. If you get a replacement be careful that it isn't one of the Chinese knockoffs that don't work. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful. Last edited by hatzie; 11-05-2018 at 10:27 PM.



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