8747 TBI killed another EGR valve after 180 miles. I'd like input about deleting.

[The_Joe]

Hey guys, this is my sister's truck. 1990 2500 with a 350 and a th400. We've spent the whole budget fixing other issues along the way, and on the final test drive before giving it back it killed the brand new EGR valve, which got stuck open.

I have a MOTES BURN1 programmer available, but the ECU is not modified to accept modern chips. I have an extra 7747 that I could barrow a chip from also.

Made a block off plate and used RTV for testing and it idles great now.



Now the question:
1. Should I just go buy another EGR valve? Do I need to just order it from a GM dealer to get reliable operation? Is this a 1/10,000 failure?

2. Should I buy a UV tool for blanking the original style chip and delete the original style chip to leave the EGR?

3. Should I solder a chip adapter and buy the EEPROM chips? Is that worthwhile on a truck that I am not modifying any further?

Just.... Frustrated with brand new parts failing and ready for the this thing to leave so I can focus on my own projects.

[tayto]

what brand did you buy did you pull intake and clean egr passages? with the block off plate is the CEL on? if no, i would leave it and move on.

[dave w]

It wouldn't cost much to have the original TBI style chip erased and reprogrammed without EGR. Several gearhead-efi members, including myself, have UV eraser's and a chip programmer's for the original TBI type chips. Maybe post your looking for custom chip programming help?

dave w

[brian617]

How did the valve fail, diaphragm or stuck pintle?

[The_Joe]

what brand did you buy did you pull intake and clean egr passages? with the block off plate is the CEL on? if no, i would leave it and move on.

Brand was cheap O'Reillys garbage. Youd think I would have learned by now.

Did I clean the passages.... Kind of. I didnt think to include this in the original post because it didn't seem relevant, but I first installed the valve on the engine in the truck, that engine turned out to be junk, and I swapped the engine with one that I had cleaned thoroughly 3 years ago. After verifying the "New" engine was working correctly with the fuel injection, I swapped the EGR onto the Good/new Engine. Ran great for about 100 miles, and then the valve failed.

Its possible that the junk engine caused the failure. I hadnt considered that.

I have not driven the truck on the highway to verify that the CEL still comes on, I just assumed that it would. That would be a good step. Thank you.


It wouldn't cost much to have the original TBI style chip erased and reprogrammed without EGR. Several gearhead-efi members, including myself, have UV eraser's and a chip programmer's for the original TBI type chips. Maybe post your looking for custom chip programming help?

dave w

Dave, I honestly hadnt even considered having someone erase the chip for me. That is a really great idea. I do have a Burn1 here that I have borrowed from my buddy, I guess I need to make another post and find out if anyone wants to give me a hand or lives in western Washington and could just blank it. It didnt seem worthwhile to buy the eraser for myself, since I would get Eeprom chips for anything I was going to modify.

Really great idea, thank you.


How did the valve fail, diaphragm or stuck pintle?

The original was a bad Diaphragm, which led me to replace it with a cheap one from O'Reillys. That one failed with a stuck pintle. Was crazy to diagnose since suddenly the truck is reporting basically no vacuum but the AFR was still correct and it was idling lower not higher.

[dave w]

Hi Joe,
I live is Southwestern Washington State, near Camas actually.

The original TBI chis is actually called a 2732 chip. There are variants of the 2732 chip like 2732A. The variants are mostly the "Burn" voltage used, 25 volts, 21 volts, or 12.5 volts. The Burn 1 does not program the 2732 chip: http://support.moates.net/burn1/

dave w

[The_Joe]

Hi Joe,
I live is Southwestern Washington State, near Camas actually.

The original TBI is call a 2732 chip. There are variants of the 2732 chip like 2732A. The variants are mostly the "Burn" voltage used, 25 volts, 21 volts, or 12.5 volts. The Burn 1 does not program the 2732 chip: http://support.moates.net/burn1/

dave w
That's only about an hour South of me! Thank you for sharing. I'm going to PM you.

Thank you for explaining, I had done my research on the Moats site related to an EEPROM chip [I don't remember the part number, it was also available on Moats site.] And I hadn't even considered that the burn1 couldn't work on the stock chips. I'm really glad I didn't just buy an eraser, I would have been very disappointed!

Still learning.