Need help 1993 Suburban2500

[redbond]

Need help 1993 Suburban2500 ECM problems

Well I'm new here and hope it works. I have a 1993 Gmc Suburban 2500 4x4 with a 5.7TBI with the 4L80E. The problem is that its sucking up the fuel with lots of knocking. The shop stated that they have checked everything and it looks like its the ECM. I have the (#16147060 BAAY). My question is that I have found many used ones for the exact same truck but the four letters don't match on the part number.......Does it have to? Some of the sellers are saying no and some are saying yes but I want to make sure? And also is it the chip or the ECM its self? Any help would be awesome!

 

[Molson02536]

Well I'm new here and hope it works. I have a 1993 Gmc Suburban 2500 4x4 with a 5.7TBI with the 4L80E. The problem is that its sucking up the fuel with lots of knocking. The shop stated that they have checked everything and it looks like its the ECM. I have the (#16147060 BAAY). My question is that I have found many used ones for the exact same truck but the four letters don't match on the part number.......Does it have to? Some of the sellers are saying no and some are saying yes but I want to make sure? And also is it the chip or the ECM its self? Any help would be awesome!

Start with the simple and clean your EGR valve and make sure your timing is right where it should be. Clean your throttle body and replace your Map sensor being a 1993.

Last also replace your knock sensor, slight faulty knock sensor that has gone bad may not set the check engine light but is not sensitive enough to send the right signals to the ECM to retard the timing. Try disconnecting the knock sensor leads and see if there is any difference, if there is no difference after your test drive. Try replacing it.

Good luck and keep us posted.
Molson02536

 

[happy 2011]

sorry i can't take it anymore! Some People on this just tell you to replace parts for the sake of replacing parts.

Any moron can throw parts at something! the thing to rember is you usally don't fix the problem doing so! In the end it just cost more money!



to answer the question i belive they all have to match.

 

[Molson02536]

sorry i can't take it anymore! Some People on this just tell you to replace parts for the sake of replacing parts.

Any moron can throw parts at something! the thing to rember is you usally don't fix the problem doing so! In the end it just cost more money!



to answer the question i belive they all have to match.

Read the answer again and if i missed something on how to fix the knocking issues he is having please to add.

Timing issue 101. The ECM is set to advance the timing as as far ahead and the signal from the Knock sensor prompts the ECM to retard the advance to keep the engine from having any detonation (knocking).

The only other thing that would cause this is a worn distributor gear or a badly stretch timing gear.

Quick fix would be to use 91 octane to help stop detonation, but that just mask the issue.

Any suggestions on how he could go about on how to address his knocking issues. I may have missed on how the PCM manages the engine's timing system.

Molson02536

 

[happy 2011]

ok here is what you missed !
Frist of all it's been to a shop and said PCM seems to be the problem. Well do you think they just threw darts at a board to decide the PCM is bad. Maybe it is maybe it's not.

But my point to you is they have already looked at it and i will BET they have looked at the DATA STREAM (something you have not) and can most liky see that the knock sensor is working or not.

Next cleaning the EGR valve lol would it be a lot easyer to check and see if it's working. Wow that would only take me about 30 secends.

O ya replace your map sensor again DATA stream! test it instead of just replace it. Very simple to test with a data stream! (i'm sure the shop did as well)

And last replace your knock sensor ! Don't test it to see if it's bad lol!

so your parts list would cost about 65 to 85 bucks and a all day job to a do it your selfer (with EGR cleaning)

Now i can tell you this his PCM is cheep to buy after market About 100 bucks or so and they have EST problems.

But what do i know ! just been doing this for a living for 30 years or so

 

[Molson02536]

ok here is what you missed !
Frist of all it's been to a shop and said PCM seems to be the problem. Well do you think they just threw darts at a board to decide the PCM is bad. Maybe it is maybe it's not.

But my point to you is they have already looked at it and i will BET they have looked at the DATA STREAM (something you have not) and can most liky see that the knock sensor is working or not.

Next cleaning the EGR valve lol would it be a lot easyer to check and see if it's working. Wow that would only take me about 30 secends.

O ya replace your map sensor again DATA stream! test it instead of just replace it. Very simple to test with a data stream! (i'm sure the shop did as well)

And last replace your knock sensor ! Don't test it to see if it's bad lol!

so your parts list would cost about 65 to 85 bucks and a all day job to a do it your selfer (with EGR cleaning)

Now i can tell you this his PCM is cheep to buy after market About 100 bucks or so and they have EST problems.

But what do i know ! just been doing this for a living for 30 years or so

Now that was not to hard for you to give out an answer to help him get his truck up and running 100% again was it???????

Molson02536

 

[Z15]

I don't know if this will help but I had a 1992 Silverado with a 5.0L engine and had the spark knock problem and no GM dealer could find a reason. One dealer supposedly had a real good tech and he flat out told me, this has me stumped as everything is the way it should be and I can't find nothing wrong. So I lived with it for over a year because I knew the engine was going to have to be replace (cracked block leaking coolant). Finally I purchased a new GM 5.0L engine and had it installed. They had to use the intake system and distributor from my old engine. Well, right out of the gate it was spark knocking bad, worse the before. One tech said, its got to be the distributor as that's from the old engine. So back in 2004 when this was happening that had to search high and low for a new GM distributor and finally located one in some dealers inventory, ordered and installed it and the spark knock was gone. None of the ace tech's find anything wrong with the oem distributor (only 72, 000 miles on engine).


NOTE : Don't go spending $$ blindly on a new distributor but I do know even the experts at the GM dealer were surprised the distributor was the cause and I likely would have never given a heck had I not put in the new engine.


PS-Block cracked because the previous owner never serviced it properly. It was traded in in the fall and sat on a Furd dealers lot thru the winter and I came along and thought it would be a good plow truck and bought it for wholesale. Coolant was mostly water.