THEMCGUIRE
1/2 ton status
Anyone know why the SES would stay on but the ECM does not report any other codes ?
CK5
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SES always on - no codes other then 12
- Thread starter THEMCGUIRE
- Start date
Check the flowcharts for either code 12 or constant SES...they must have something for it.
When you jumper the A/B terminal, does it actually flash, or just stay on? The ECM grounds the bulb to turn it on, only thing I can think of would be short to ground on that wire to the ECM (or failed ECM), but that shouldn't let it flash codes at all obviously.
When you jumper the A/B terminal, does it actually flash, or just stay on? The ECM grounds the bulb to turn it on, only thing I can think of would be short to ground on that wire to the ECM (or failed ECM), but that shouldn't let it flash codes at all obviously.
THEMCGUIRE
1/2 ton status
if i jumper the two upper right slots it flashes 12 over and over and over,
so that is why I dont think it's a ground.
Will check the flow charts
thanks
so that is why I dont think it's a ground.
Will check the flow charts
thanks
Definitely something odd if it will still flash codes.
Pull the PROM, blow the socket out real good, and reseat it. That's what I'd do first.
I assume when you turn the truck to "run" from off, that the light doesn't flash once, like its supposed to. Should be: light on when key turned to run, quick flash off, back on, then stay on until truck starts. If you don't get the quick flash, something is wrong with the PROM.
Pull the PROM, blow the socket out real good, and reseat it. That's what I'd do first.
I assume when you turn the truck to "run" from off, that the light doesn't flash once, like its supposed to. Should be: light on when key turned to run, quick flash off, back on, then stay on until truck starts. If you don't get the quick flash, something is wrong with the PROM.
have you tried disconnecting and reconnecting the battery?
That's easy too. 
Another one of those never hurts deals.
Another one of those never hurts deals.
I wouldn't do this til you exhaust other options, but a new ECM is only like $150 if you get to that point.
IIRC this is a new ECM already.
THEMCGUIRE
1/2 ton status
you do recall correctly, this is a new ECM. and the battery has been disconnected on and off for months. I always pull the batter cable when working on the electrics and have put relays on headlights and door, and other stuff recently.
Just took it for it's 1st ride since 2009. I just went around the block.. there is a funny smell out of the exhaust...
It's not registered, but it is insured so I did not want to go far.
After the 1st block the light went out. As soon as I parked it the light came on. I Just got back from the doctor and wearing my fancy go to doctor clothes. lol, otherwise I would do more checking.
So I went out and turned the key and the light came on. This time got a code 44. Since the exhaust system is new from the headers back, and since I am in the "replace to rejuvenate" state of mind I will replace the O2 sensors tomorrow and take it for another test drive. Will report back asap.
Just took it for it's 1st ride since 2009. I just went around the block.. there is a funny smell out of the exhaust...
It's not registered, but it is insured so I did not want to go far.
After the 1st block the light went out. As soon as I parked it the light came on. I Just got back from the doctor and wearing my fancy go to doctor clothes. lol, otherwise I would do more checking.
So I went out and turned the key and the light came on. This time got a code 44. Since the exhaust system is new from the headers back, and since I am in the "replace to rejuvenate" state of mind I will replace the O2 sensors tomorrow and take it for another test drive. Will report back asap.
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12 is a code, but shows up when doing the paperclip A to B trick because the engine is not running.
"12. No reference pulses to Electronic Control Module (ECM)." SO it should go off when engine is running.
Now that the SES went off I think it's fine, your other code is why it came back on.
"44. Oxygen sensor lean" Is rarely an O2 sensor. The engine is running leaner then allowed when tests are run, so it sets a 44. Usual issue is low fuel pressure...
"12. No reference pulses to Electronic Control Module (ECM)." SO it should go off when engine is running.
Now that the SES went off I think it's fine, your other code is why it came back on.
"44. Oxygen sensor lean" Is rarely an O2 sensor. The engine is running leaner then allowed when tests are run, so it sets a 44. Usual issue is low fuel pressure...
THEMCGUIRE
1/2 ton status
What causes that ?
I have a new fuel pump, new filter, new left injector (The old one just dripped out, no real conical spray). The right injector spray pattern, to the naked eye, looks just like the new left one
I have put a pint of marvel mystery oil and a bottle of injector cleaner through the system, (running at idle for hours over a period of about 3 weeks now. I calculate I used about 15 gallons of gas so far.)
I did notice that when I tried to step on it, on my around the block trip today, it did not seem to have any oomph, like I remember it had 5 years ago.
I have seen fuel pressure adjustors for sale, do I need to go that route ?
or should I take it out on the highway and run it for a while first ?
Does the fuel injector cleaner also clean the fuel lines ?
I had to disassemble the TBI to install the new injector, could I have messed something up. If I cracked the gasket could that be letting air in and thereby lowering the pressure ? (I do not see any gas leaking anywhere)
Will this help: GM TBI 40hp power up kit 1986-95 SBC 2.8 4.3L 5.0L 5.7L
found it on ebay: http://www.ebay.com/itm/GM-TBI-40hp...Parts_Accessories&hash=item2c73b1390e&vxp=mtr
I have a new fuel pump, new filter, new left injector (The old one just dripped out, no real conical spray). The right injector spray pattern, to the naked eye, looks just like the new left one
I have put a pint of marvel mystery oil and a bottle of injector cleaner through the system, (running at idle for hours over a period of about 3 weeks now. I calculate I used about 15 gallons of gas so far.)
I did notice that when I tried to step on it, on my around the block trip today, it did not seem to have any oomph, like I remember it had 5 years ago.
I have seen fuel pressure adjustors for sale, do I need to go that route ?
or should I take it out on the highway and run it for a while first ?
Does the fuel injector cleaner also clean the fuel lines ?
I had to disassemble the TBI to install the new injector, could I have messed something up. If I cracked the gasket could that be letting air in and thereby lowering the pressure ? (I do not see any gas leaking anywhere)
Will this help: GM TBI 40hp power up kit 1986-95 SBC 2.8 4.3L 5.0L 5.7L
found it on ebay: http://www.ebay.com/itm/GM-TBI-40hp...Parts_Accessories&hash=item2c73b1390e&vxp=mtr
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you need to put a gauge on it and see what pressure your getting.. that's pretty much THE first diagnostics for ANY EFI system.. just throwing a bunch of parts at it doesn't tell you the prob...
low voltage, weak pumps can all give low pressure.. brand new tbi pumps barely put enough pressure out if they work correctly. let alone if you have a voltage, etc issue...
I run adjustables on all my tbi's.. probably the best bang for the buck power mod you can do, bump it to 13.5-13.8 and you'll feel it in the pants too..
low voltage, weak pumps can all give low pressure.. brand new tbi pumps barely put enough pressure out if they work correctly. let alone if you have a voltage, etc issue...
I run adjustables on all my tbi's.. probably the best bang for the buck power mod you can do, bump it to 13.5-13.8 and you'll feel it in the pants too..
THEMCGUIRE
1/2 ton status
so i need a way to measure it. Is the following a good part to get to accomplish this ?
CFM-Tech Fuel Psi Guage Adapter For GM Tbi 2.8/4.3/5.0/5.7/7.4
and do I need
CFM-Tech Adjustable Fuel PSI Regulator for GM TBI 2.8/4.3/5.0/5.7/7.4
can you recommend a fuel pressure gauge as well ?
Reading the articles at CFM they recommend 14 psi that gives more horses and they may actually use less fuel (along with some other add on's of course.
or is the following kit better it looks less costly:
Actron Gauge Fuel Pressure 0-60 psi 2 1/4" Analog Mechanical GM TBI Adapter Kit
http://www.ebay.com/itm/Actron-Gaug...Parts_Accessories&hash=item5af534f289&vxp=mtr
BTW Royken, you know me too well. I do like to put new parts. My reason for this is that the truck is 25 years old, Having just spent 12,000 on it rebuilding the body I feel that a little more on new stuff will only be a benefit since the stuff is so old and the body has zero miles on it. Rejuvenation being the long term goal.
There is max 50,000 miles on the jasper engine, and 20,000 on the rebuilt trans and front end.
CFM-Tech Fuel Psi Guage Adapter For GM Tbi 2.8/4.3/5.0/5.7/7.4
and do I need
CFM-Tech Adjustable Fuel PSI Regulator for GM TBI 2.8/4.3/5.0/5.7/7.4
can you recommend a fuel pressure gauge as well ?
Reading the articles at CFM they recommend 14 psi that gives more horses and they may actually use less fuel (along with some other add on's of course.
or is the following kit better it looks less costly:
Actron Gauge Fuel Pressure 0-60 psi 2 1/4" Analog Mechanical GM TBI Adapter Kit
http://www.ebay.com/itm/Actron-Gaug...Parts_Accessories&hash=item5af534f289&vxp=mtr
BTW Royken, you know me too well. I do like to put new parts. My reason for this is that the truck is 25 years old, Having just spent 12,000 on it rebuilding the body I feel that a little more on new stuff will only be a benefit since the stuff is so old and the body has zero miles on it. Rejuvenation being the long term goal.
There is max 50,000 miles on the jasper engine, and 20,000 on the rebuilt trans and front end.
You really need to know what the fuel pressure is! If your going to throw parts at it anyway the CFM gauge and adjustable regulator is a good thing!
New fuel pump means nothing! Name brand and upgrading to TPI pump is a better deal.
Replacing one injector is not a good thing. Having both injectors serviced is a good thing! Then you know they are both the same. Your eye is not a good thing for fuel flow!
The actron gauge works... but not very accurate since it is 0 to 60 swing and we are trying to get 1 lb readings. The ones I have used in person also shake so bad it's useless.
New fuel pump means nothing! Name brand and upgrading to TPI pump is a better deal.
Replacing one injector is not a good thing. Having both injectors serviced is a good thing! Then you know they are both the same. Your eye is not a good thing for fuel flow!
The actron gauge works... but not very accurate since it is 0 to 60 swing and we are trying to get 1 lb readings. The ones I have used in person also shake so bad it's useless.
THEMCGUIRE
1/2 ton status
Auto zone has fuel pressure testing in lend a tool. Going that route 1st, if pump fails the test your saying to replace it with a better one.
Can you recommend a fuel pump for me ?
also, can the CFM-Tech Fuel Psi Guage Adapter For GM Tbi 2.8/4.3/5.0/5.7/7.4 be left on the truck after the test
Can you recommend a fuel pump for me ?
also, can the CFM-Tech Fuel Psi Guage Adapter For GM Tbi 2.8/4.3/5.0/5.7/7.4 be left on the truck after the test
AC/Delco, Carter or Walbrough from 90 TPI camaro or 96 5.7L vortec truck is direct bolt in. Capable of more pressure and flow, your regulator will handle it.
Yes that adapter is designed to be left on truck. These is an issue with some gauges loosing pressure when hot so only use pressure reading when cold. Or plumb from adapter and mount gauge on hood where you can see pressure while driving WOT high RPM, this is where pressure will drop if pump can't keep up. DO NOT plumb gas into passenger compartment.
Yes that adapter is designed to be left on truck. These is an issue with some gauges loosing pressure when hot so only use pressure reading when cold. Or plumb from adapter and mount gauge on hood where you can see pressure while driving WOT high RPM, this is where pressure will drop if pump can't keep up. DO NOT plumb gas into passenger compartment.
yes, you can leave the gauge in, most do... I run an Autometer out on the hood for "while driving monitoring", plumbed into the CFM adapter...
and I also run a Walbro 255 out of the early 90's TPI maro's... 14 psi rock steady... about $125....
THEMCGUIRE
1/2 ton status
this one WALBRO GSS342 IN TANK 255LPH HP GENUINE FUEL PUMP ?
but you have the adjustable fuel regulator, right... Does that have to be put in before this pump or can I try the pump and then add the fuel pressure regulator later ?
but you have the adjustable fuel regulator, right... Does that have to be put in before this pump or can I try the pump and then add the fuel pressure regulator later ?
Opinion: running a fuel pressure gauge all the time is pointless and unnecessary. Borrow the autozone tool, hook it up *at the end of the braided hose from the engine near the frame rail* but you aren't going to be able to test it running, and someone will have to watch the gauge as you step on the throttle, the hose isn't long enough to reach anywhere you can see it. You will get drenched with fuel unfortunately, due to the design the fuel line will siphon from the tank while you are disconnecting the line and connecting the fitting for the gauge.
Did you check/replace all vacuum hoses while you were underhood? Vacuum leak can cause an O2 SES as well.
Did you check/replace all vacuum hoses while you were underhood? Vacuum leak can cause an O2 SES as well.
THEMCGUIRE
1/2 ton status
1'st off, what do you mean by "but you aren't going to be able to test it running,"
Please don't be annoyed but I went to replace the O2 sensor, could not get it off, but, I found the wire was pinched between two parts of the bell housing. The CES light has been on for as long as I can remember but I had just ignored it before this.
I guess it was like that since the engine was replaced. Over time with vibration I guess it worked the insulation off until it shorted. So I cut the wire, spliced it back together by passing the pinch, disconnected the battery for 30 seconds, took it for a ride and no code.
But, the acceleration could be smoother. Got the fuel pressure kit from autozone and a TBI rebuild kit. Tomorrow I will pull the TBI, rebuild it, and install the adapter and test the fuel pressure.
Thanks for all your help and advise so far.
I have been looking at the Walbro GSS 342 255 that Royken mentioned.
Got the following info"
Walbro "255" LPH GSS-317 12.5V 43psi 7.5amps 229.02 Ltr/Hr
Walbro "255" LPH GSS-317 12.5V 58psi 9.0amps 201.89 Ltr/Hr
Walbro "255" LPH GSS-317 12.5V 73psi 10.5amps 147.00 Ltr/Hr
Walbro "255" LPH GSS-317 14.0V 43psi 8.0amps 261.83 Ltr/Hr
Walbro "255" LPH GSS-317 14.0V 58psi 10amps 230.92 Ltr/Hr
Walbro "255" LPH GSS-317 14.0V 73psi 11.5amps 182.97 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 12.5V 43psi 7amps 233.4 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 12.5V 58psi 9amps 210.10 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 12.5V 73psi 10.5amps 189.3 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 14.0V 43psi 8amps 264.4 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 14.0V 58psi 9.5amps 242.9 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 14.0V 73psi 11amps 220.8 Ltr/Hr
All tests show fuel pressure of 43, 58 and 73 psi.
Won't this blow out my pressure regulator ?
My max pressure should be 14 psi, correct ? Am I looking at the wrong pump ?
Oh btw, I put a 1993 Cherokee steering shaft in today as well. OMG 30 min work and the steering is beautiful now. FYI....
Please don't be annoyed but I went to replace the O2 sensor, could not get it off, but, I found the wire was pinched between two parts of the bell housing. The CES light has been on for as long as I can remember but I had just ignored it before this.
I guess it was like that since the engine was replaced. Over time with vibration I guess it worked the insulation off until it shorted. So I cut the wire, spliced it back together by passing the pinch, disconnected the battery for 30 seconds, took it for a ride and no code.
But, the acceleration could be smoother. Got the fuel pressure kit from autozone and a TBI rebuild kit. Tomorrow I will pull the TBI, rebuild it, and install the adapter and test the fuel pressure.
Thanks for all your help and advise so far.
I have been looking at the Walbro GSS 342 255 that Royken mentioned.
Got the following info"
Walbro "255" LPH GSS-317 12.5V 43psi 7.5amps 229.02 Ltr/Hr
Walbro "255" LPH GSS-317 12.5V 58psi 9.0amps 201.89 Ltr/Hr
Walbro "255" LPH GSS-317 12.5V 73psi 10.5amps 147.00 Ltr/Hr
Walbro "255" LPH GSS-317 14.0V 43psi 8.0amps 261.83 Ltr/Hr
Walbro "255" LPH GSS-317 14.0V 58psi 10amps 230.92 Ltr/Hr
Walbro "255" LPH GSS-317 14.0V 73psi 11.5amps 182.97 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 12.5V 43psi 7amps 233.4 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 12.5V 58psi 9amps 210.10 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 12.5V 73psi 10.5amps 189.3 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 14.0V 43psi 8amps 264.4 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 14.0V 58psi 9.5amps 242.9 Ltr/Hr
Walbro "255 High Pressure" LPH GSS-342 14.0V 73psi 11amps 220.8 Ltr/Hr
All tests show fuel pressure of 43, 58 and 73 psi.
Won't this blow out my pressure regulator ?
My max pressure should be 14 psi, correct ? Am I looking at the wrong pump ?
Oh btw, I put a 1993 Cherokee steering shaft in today as well. OMG 30 min work and the steering is beautiful now. FYI....
