91 suburban still Dead in the water no pulse at injectors

[kennythewelder]

Keep in mind guy's, this is an OBD1 ECM, and any codes can be pulled with a paper clip. Since I haven't had an OBD1 system in well over 10 years, I'm not sure what kind of system readers are available for this system. Is there a live date reader for OBD1? Where you at @PlayingWithTBI

 

[evilunclegrimace]

Keep in mind guy's, this is an OBD1 ECM, and any codes can be pulled with a paper clip. Since I haven't had an OBD1 system in well over 10 years, I'm not sure what kind of system readers are available for this system. Is there a live date reader for OBD1? Where you at @PlayingWithTBI

A Snap on brick will read data on OBD1

 

[smdk2500]

Keep in mind guy's, this is an OBD1 ECM, and any codes can be pulled with a paper clip. Since I haven't had an OBD1 system in well over 10 years, I'm not sure what kind of system readers are available for this system. Is there a live date reader for OBD1? Where you at @PlayingWithTBI

My snap on solus edge will read obd1. They are out there just have to look.

 

[kennythewelder]

A Snap on brick will read data on OBD1

IDK what a Snap on brick is. Maybe you can order snap on products on line, IDK, but I do know that back when, snap on was only available from a snap on truck. Not something everyone has access to. Not to mention, snap on is the most high dollar tools out there, or at least they used to be.

 

[yevgenievich]

There are cheap computer interfaces to read those. I kept an adapter in console on mine just in case. Just need to verify ecm is getting the right signals and go from there

 

[evilunclegrimace]

IDK what a Snap on brick is. Maybe you can order snap on products on line, IDK, but I do know that back when, snap on was only available from a snap on truck. Not something everyone has access to. Not to mention, snap on is the most high dollar tools out there, or at least they used to be.

It is the long discontinued MT2500

 

[kennythewelder]

There are cheap computer interfaces to read those. I kept an adapter in console on mine just in case. Just need to verify ecm is getting the right signals and go from there

Got ya. Like I said, I have fools with OBD1 in 10 plus years.

 

[Schurkey]

Is there a live date reader for OBD1?

Many.

A Snap on brick will read data on OBD1

That's what I used for 20 years.

IDK what a Snap on brick is. Maybe you can order snap on products on line, IDK, but I do know that back when, snap on was only available from a snap on truck. Not something everyone has access to. Not to mention, snap on is the most high dollar tools out there, or at least they used to be.

There's a wide variety of Snap-On scan tools, used, on eBay, pawn shops, and Craigslist.

All of mine have come from eBay. Most recent cost me $350 shipped to my door.

I keep NOT working up the gumption to create a scan-tool thread with my current unit. But there's a thread* on another forum that details what can be had from my '88 K1500 using the latest version of the Snappy Red Brick (MTG2500, similar to the MT2500)

For the record, the MT2500 was released in 1988. They're ancient. Nice thing about them is that the software is written on replaceable cartridges; updating to newer/different software is as simple as yanking one cartridge out, and slapping in a different one. Much like changing magazines in a semi-auto pistol.

Less-ancient scan tools do more things on newer vehicles. The MT/MTG2500 series were state-of-the-aftermarket art in the late '80s; but they're wildly outclassed today; and the newest software available was released in 2009--and that's rare. I've never seen a software cartridge that new. My machine only went from 1980 1/2 to 2006, using two cartridges. I never did have early Asian software, or any European at all. My newer machine does have decent Asian and some European coverage, which I've never used.

*THIS THREAD, starting at Post #14; but the earlier posts are kinda humorous. The photos are there, if you aren't seeing them, it's likely due to an ad-blocker or some such on your computer.
www.automotiveforums.com/vbulletin/showthread.php?t=1146067

94 k2500 no low end power and horrible fuel mileage - Automotive Forums .com Car Chat

94 k2500 no low end power and horrible fuel mileage C/K

www.automotiveforums.com

 

[Eveready]

Knowing these truck's immense ability to mask a bad ground for a wide variety of ills I am naturally suspicious of a ground issue somewhere. Also the fuel pump is a real possibility. Do you hear it "priming" when you turn the key? Have you checked fuel pressure? I think I would start there and if the fuel pump is PROVEN to be ok then start chasing grounds.

 

[PlayingWithTBI]

Where you at @PlayingWithTBI

As mentioned above, the "Red Brick" is probably the most popular among professionals and is readily available since most folks in the business have upgraded to newer Snappy versions like the Solus Pro and Solus Ultra which is now no longer supported as of 01/2022.

For an alternate option with a laptop, there's TunerPro RT and an ALDL cable for data logging, and the Moates Burn2 for programming and flashing chips. In this case the ECM will have to be modified to accept a flash chip for modifying/programming the .bin. There are emulators available too but, that's a different story.

As an example, if you have the 1227747 ECM you'll need the coinciding $42 .adx mask file for it too. Anyway, TunerPro RT is free (with a suggested contribution), the ALDL cable is ~$60 and, with some reading and practice, you're in business for data logging, while driving around, as long as you want.

www.tunerpro.net/

www.aldlcable.com/

Here's some info about the different ECM/PCMs used in our trucks as well as other cars including wiring diagrams, etc.

www.gearhead-efi.com/Fuel-Injection/forumdisplay.php?20-GM-ECM-Bins-TunerPro-Definition-Files-Wiring-Diagrams-Tuner-Info

Here's an example of your 12 pin OBDI connector and what pins do what. For example, if you want to test your A.I.R. Diverter, simply ground pin "C".

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Here's an example of a data log screen in TunerPro RT

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Here's a data stream from TunerPro RT showing O2 sensor, RPM, MPH, CTS, Knock Counts, INT, BLM, IAC, and TPS all at the same time. You can adjust the time frame of the scan to drill down to where your issue(s) is happening. In your case, turn on the scan and try cranking the engine for a while, then look at the data to see if you're getting RPM feedback as well as other sensors.

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Just another option of many, HTH