NO Spark...... TBI 88 GMC 5.7 350

[89Suburban]

hey sorry i haven't posted in a few days, i'm still stuck . would it be possible that the ECU went bad? Ive heard some people say they very rarely go bad. i think its time to drag her to a garage. thanks for all the help fellas!

Ahhh ****, let us know what they say bro.

 

[Jims86]

hey sorry i haven't posted in a few days, i'm still stuck . would it be possible that the ECU went bad? Ive heard some people say they very rarely go bad. i think its time to drag her to a garage. thanks for all the help fellas!

It is possible, but, do you get a steady burning check engine light when you turn the key to on?If you can get trouble codes from it, the ecm is good.

 

[mhelms83]

I dont have a code reader so it hasn't been tested yet. I did verify that it was getting power at both the fuse panel and the plug (pink wire) Is there much more to the ignition system? Could a bad starter solenoid cause the problem? I think ive tested or replaced everything else. Oh, and a pic of the engine compartment. Tell me what you think.

 

[89Suburban]

I dont have a code reader so it hasn't been tested yet. I did verify that it was getting power at both the fuse panel and the plug (pink wire) Is there much more to the ignition system? Could a bad starter solenoid cause the problem? I think ive tested or replaced everything else. Oh, and a pic of the engine compartment. Tell me what you think.

You don't need a reader, just a paper clip and count the flashes.

Not sure if there is a write up in here on that or not, let me look.....

 

[Jims86]

I dont have a code reader so it hasn't been tested yet. I did verify that it was getting power at both the fuse panel and the plug (pink wire) Is there much more to the ignition system? Could a bad starter solenoid cause the problem? I think ive tested or replaced everything else. Oh, and a pic of the engine compartment. Tell me what you think.

You dont need a code scanner, you can diagnose with a paper clip and watching the check engine light.
Your diagnostic connector is under the dash, below your steering column. Jump A and B together with a wire or paperclip. the first code you will see, is code 12....1 flash, a short pause, and then 2 flashes. each present trouble code will flash 3 times.
Just turn the key to the on position after you jump the terminals with the paper clip, to the point where the dash lights come on, DO NOT TRY TO START THE ENGINE!

You must be registered for see images attach

 

[HotRodPC]

No doubt, all an OBD Code 1 reader is, is a jumper block that makes sure you hit the right pins. You can do it yourself as said above and count the flashes.

 

[89Suburban]

...and here's the codes Jimbo posted:

http://www.gmsquarebody.com/forum/showpost.php?p=51384&postcount=6

Trouble Code

SYSTEM

Indicating
12 Diagnostic Checking for operation of CEL bulb
13 Oxygen Sensor Circuit No signal to computer
14 Coolant Sensor Circuit Excessive HIGH temperature indicated
15 Coolant Sensor Circuit Excessive Low temperature indicated
16 VSS - Vehicle Speed Sensor Signal Loss
21 TPS - Throttle Position Switch High Signal Voltage
22 TPS Low Signal Voltage
24 VSS Set when in motion only - disregard if set in park
32 EGR EGR system failure
33 MAP - manifold absolute pressure sensor MAP sensor voltage high
34 MAP MAP sensor voltage low
35 IAC - Idle Air Control Motor Idle speed above/below desired idle speed
36 Idle Speed Control Actuator Open or Short Circuit
42 Ignition Control open/short/component failure
43 ESC - electronic spark control ESC module not receiving knock sensor signal
44 Lean Exhaust Low oxygen sensor voltage
45 Rich Exhaust High oxygen sensor voltage
51 PROM (Memcal) Faulty computer chip
53 System voltage high Carging System is over 17.1 volts
54 Fuel pump relay Low voltage / short
55 ECM Computer (ECM) failure

 

[89Suburban]

Hey Jim, I think we are going to have a new write up on this over the weekend, on a few things maybe.....

 

[Jims86]

Only 5 years for efi on the squares, but Damn! It sure has exploded here lately!

 

[HotRodPC]

Yep, get a TBI thread going. Discussing codes, ALDL jumping wiring harness mods etc. I still want to do a Conversion Sub Cat for TBI, Vortec and LS. Gonna have to hit the Shagster up again.

(Optional Off-Topic Reading)
As much as I hate to, I'm thinking of punting on my long time dream of a ChevrOldslet and punting on my Olds 455 project in lieu of wanting to do some electronic converstions. But maybe not. I want Injection in the 4x4's so I don't have to worry about angles and carb floats. The Olds 455 project is intended for a 2wd 3/4 ton.

 

[adinpoor1995]

You would be horrified to know how many kids around my age cant even start a carbed car. Every kid in school just wants to work on mustangs and ****... Luckily ive had the blessing of growing up with these trucks and new and old benzes, fords ect.. There arent that many guys who can work on anything you put in front of them either... Everyone goes to uti or wyotech and thinks theyre a mechanic because theyre diploma says so.... Long gone is the day of the true mechanic... Sorry for the rant.

 

[HotRodPC]

I know we're gonna have to clean this guys thread up. Hopefully he get this figured out, but in the mean time, seems to be the place to discuss old school and new school, so have no fear Mike, we can fix the thread even if we can't fix your truck.

I see your point totally. I have my own views on the subject. I myself consider the old school mechanics as that. Mechanics. Today guys who work on cars like at the dealerships, I consider technicians. I'm sure some of you can see where I"m going with that. And of course back in the days of "Mechanics" you had parts changers. Today, in the world of "Technicians" you still have parts changers and alot of them. Difference benig, today you can spend a fortune changing parts because by the time you buy all the related sensors, pumps, wires, etc etc, you've now gone broke trying to guess the problem.
I will never ever knock a guy for NOT knowing what he is doing, so long as he is "not knowing" what he is doing properly. As I raised my kids, Being ignorant is OK, being Stupid is NOT OK. The word ignorant in the dictionary is, "lack of knowledge" It's OK to not KNOW something. But, don't be stupid and not know where to go to get that knowledge, or be to lazy to seek that knowledge, then you're no longer ignorant on the subject matter. As I've often said about forum, and especially this one, because lets face it, we have some damn good knowledgable people here, and some are more expert in other fields than others so we can actually claim to have specialists in certain fields if that makes sense. I tell newbies, none of us here know everything about these squares, but between all of us, we damn sure do. And if we don't we'll get the info one way or another. I've always claimed to know a little about alot, but alot about a little, and that is true, but I don't fear any project because I know I have an unlimited info source. I will never look down on a guy for not knowing something as long as he's willing to learn and get to know the info.

 

[HotRodPC]

Hopefully Mike was able to figure out pulling his codes and have some more info for us to chew up and think about.

 

[mhelms83]

so i got some paperclips and ran the tests. i guess my check engine light doesn't work because i didn't get anything. should i remove the ecu and bring it somewhere to be tested?

 

[Jims86]

so i got some paperclips and ran the tests. i guess my check engine light doesn't work because i didn't get anything. should i remove the ecu and bring it somewhere to be tested?

Nope, hold th phone. Look in port "D" of your diagnostic terminal. that is anothe wire branching off of the check engine light...If there is a pin inside of it.
stick a 12 volt test light probe in the plug, and then put the wire clip onto a positive power source, like another paper clip stuck in one of the fuse box ports marked "shunt" Those are constant power sources. then jump a and b to see if you get a light.
Also, have you had a helper crank the engine while you look under the air cleaner for fuel spray from the injectors?
Can you hear your fuel pump come on before you crank the engine?
This is all stuff that will tell us if you have a bad ECM.
Also, double check your ecm and ecm 2 fuses, as well as gauge/idle if you have it.