CK5
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Tbi help needed
- Thread starter 83ChevyK5Blazer
- Start date
I noticed my hose was split not by the pump pressure, which read fine, but by the fact that as soon as the pump shut off, pressure immediately dropped to zero.
You really should fix the CEL first, that is a known issue. It may be able to give you a clue as to what's going on.
You really should fix the CEL first, that is a known issue. It may be able to give you a clue as to what's going on.
I had this same issue. Drove me up a wall. When I got the Jimmy running in sock form. I went through everything. My dad who was a TBI guru went through it all with me again. Left me high and dry at freeway speeds multiple times. Let it sit 15 or 20 minutes and would fire up and continue. I replaced everything but the fuel lines, eventually.
The problem was the fuel boiling in the inline filter. Exhaust was too close. Heat shield fixed the issue.
The problem was the fuel boiling in the inline filter. Exhaust was too close. Heat shield fixed the issue.
I'll check the pipes, it's just frustrating because in the 2 years since i put it together I've done long trips, like to stoney which is 6 hours of highway driving with no issues.
I'll check the pressure drop as well.
I'll check the pressure drop as well.
Maybe the basket in tank came loose?
I'd say you're more than a little rich...here's what mine looked like after just under two years. Don't think your stalling is the plugs, though....
Okay, CEL doesn't appear to work anymore, i took apart the panel and swapped in a good bulb, it doesn't come on with the ignition anyway.
@ktmoutfront, the exhaust has plenty of room.
The autometer gauge I'm using goes to 9 psi, when i turn the ignition to on, the goes back to zero, when i start the truck, it goes to 11 psi, i was able to get the gauge to fluctuate slightly when revving with no load on the engine. It is also still sounding like it has a miss, and was running really rich.
@ktmoutfront, the exhaust has plenty of room.
The autometer gauge I'm using goes to 9 psi, when i turn the ignition to on, the goes back to zero, when i start the truck, it goes to 11 psi, i was able to get the gauge to fluctuate slightly when revving with no load on the engine. It is also still sounding like it has a miss, and was running really rich.
How common is it for the throttle body regulator to go bad? Didn’t you freshman that up during the motor swap?
I regasketed the throttle body when i put it in 2 years ago
Killain
Registered Member
If your using a stock GM TBI setup, then why doesn't the ECM work ? The TBI won't operate properly if there is no signal from the temperature sensor, the oxygen sensor and proper fuel pressure. How does it run if the ECM is out of commission ? Throwing parts and a broken ECM is a waste of money and time ?
The ECM does work, or else it wouldn't be starting, or driving, it just runs like garbage and dies when hot........
Killain
Registered Member
Well if it's working Ok, then it would leave a code of some sort ? I had a year worth of trouble with my Blazer and my 90 Silverado pu and in the end both trucks needed a new ECM as there were broken wires inside them both.
Technically that's not entirely true. Limp mode on these things is sometimes pretty decent, enough to run and drive at a minimum. Your problems dont sound like it (except running poorly) but known issues should get fixed first.
Need to figure out why the CEL doesnt work. It's the self test to indicate the ECM is working properly, and yours fails this.
I'm not too well schooled with EFI,but if it has a fuel pressure regulator,sometimes the diaphragm in them will rupture and suck raw fuel into the intake and cause stalling,flooding symptoms,etc..
@83ChevyK5Blazer do you know what number computer you have? I have the 7447 from my Blazer if you can test with it.
I’d be looking for heat saturation points. The CEL, like others have said, is the heartbeat monitor. If the ECM is faulty, a circuit could be breaking down with heat within the ECM. I’d be looking at any stored codes, either with a reader or the light.
ALDL droid is a tool I picked up when I was having TBI issues after I converted a 79 carbed engine to a GM TBI using the stock non TBI heads and a performer intake. The ALDL droid gives real-time data from the ECM to an Android phone. The software is now $20 I think.
https://www.ebay.com/itm/12-Pin-ALDL-OBD1-Bluetooth-and-USB-Scanner-Code-Reader-Adapter/273946503846
I was having hesitation, stumbling and poor performance issues. I had a vacuum leak on the intake from the conversion but that doesn’t sound like your issue.
ALDL droid is a tool I picked up when I was having TBI issues after I converted a 79 carbed engine to a GM TBI using the stock non TBI heads and a performer intake. The ALDL droid gives real-time data from the ECM to an Android phone. The software is now $20 I think.
https://www.ebay.com/itm/12-Pin-ALDL-OBD1-Bluetooth-and-USB-Scanner-Code-Reader-Adapter/273946503846
I was having hesitation, stumbling and poor performance issues. I had a vacuum leak on the intake from the conversion but that doesn’t sound like your issue.
I can’t remember, is the motor stock?
Whenever you’re ready. The auto vs 4pd programming is in the PROM, right?
I couldn’t remember if you changed the cam.
