In your opinion would it be worth another TBI rebuild 1st before swapping fuel systems??
CK5
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**FIXED!!**DEFINITELY***Super HIGH idle after multiple parts replacement - TBI 1990 K1500 350engine
- Thread starter ZombieK5
- Start date
I think the TBI is a nice stable stock engine management system. It is very simple and pretty reliable. If you are going to keep the engine mostly stock I say fix the TBI.
If you are going to modify the engine then upgrade to a performance system.
If you are going to modify the engine then upgrade to a performance system.
TBI rebuild kit on the way. I'll double check this assembly.
I know you didn't do this on purpose but I wanted to be clear for others reading, I do not recommend the sniper, we were looking at the Fast Ez EFI, the Edelbrock EZ Street EFI, or the Holley Terminator X stealth to use your stock intake and an adaptor. I don't recommend any EFI that has the ECU in the throttle body. Or we could just replace the intake and no adaptor.
However, I also agree with Wes, if you are leaving the engine stock and you can get the stock system running correctly, you could be happy with it. If you are going to modify the engine or replace it then we could get you an aftermarket system to get you running better than new.
However, I also think that 11 psi should still keep it running, even if it's not running optimally.
These issues can be frustrating, especially when you have replaced so many parts and the problem still exists.
How old are the injectors? New or rebuilt what brand?
NEW GM Genuine injectors replaced last year... When all this started. They seem to work fine. When the engine was running they put out a very steady cone of gas. There was no dripping or issues. Again, they were brand new Factory injectors.
I have a poor memory, and am thinking this engine had the heads off ? If so, now am wondering if the valves are to tight, maybe not all but a few.
Engine has not been apart. The engine was running fine when I replaced all the serpentine belt components and rebuilt the TBI.
OK, TBI rebuild kit is on the way and should be to my place on friday. I'll take the existing unit off and have it ready to go. I should have it back together and back on the truck by sunday. Sunday is my next real day off from work. I'll do my best to photograph and document the rebuild just in case I do something wrong. I'll post the photographs and let me know what I missed.
I am praying that the rebuild kit comes with the two little white nylon washers that go on the fuel line return and and fuel line intake ports. If you know what I'm talking about and you know a source where I can pick up about 10 of those let me know. I can't find any place that sells just those little white nylon washers. The ones I have are in bad shape but they currently don't have any leaks. I really don't want to press my luck.
McMaster car sells every size of nylon washer if you know the dimensions.
The washer has a special lip on it that is unique. It's not just a regular old everyday washer.
Any chance the big spring in the regulator could be wrong? I had replaced it but l it came with a kit...I see now they have different springs that offer different psi ratings.
If there is more than one spring option that could definitely be wrong. However, I don't think 11 psi vs 13 psi would make it not run, it would more likely not run optimally. But it's certainly possible. Try the other springs and see what the pressure readings are before you start the engine.
I saw one of those in a video but haven't seen one for sale.
Amaze... Amaze...Amaze
New regulator spring came in. I also realized that I can remove the regulator without removing the whole throttle body unit.
Tore the regulator out and removed the existing spring, which was new a year ago, and compared it to the one I purchased off of Amazon that advertised for 12 to 14 psi. It's obviously taller and a little bit thicker. I installed it and replaced the gasket and turned the ignition on (did not start it) and it showed 12 psi. I turnes the motor over and it started right away and ran almost perfectly. As it started to heat up, about 20 minutes later, I found that it was starting to surge again unfortunately.
I took it a for a spin and it ran like sh*t. Crawled back under the hood and did some more digging around. I happened, by just pure luck, to look at the driver side fuel injector and there was gasoline pooling on the top of it. Upon closer examination I saw that about every two or three seconds and additional drop of gas fell into the throttle body port on the driver side. I'm guessing whenever that extra gas dropped in the RPMs spiked upward and then fell back down again until the next extra drop of gas fill in. So I took the regulator off again and remove the driver side fuel injector. I replaced it with one of the old injectors. I put on a new filter and o-ring and it snapped right in place. I started the engine and it ran almost perfect with no surging. It's been running out for 20 minutes with no surging and a steady 740 rpms. I took it for a spin and it is running about 85%. I think when I get my new throttle body rebuild kit from RockAuto tomorrow I'm going to replace the passenger side injector with the old injector. All of this freaking work and it was a bad injector which was a GM Genuine injector. I didn't put in a POS aftermarket injector. I'm I'm saying it's 90% fixed. I'll know more this weekend
New regulator spring came in. I also realized that I can remove the regulator without removing the whole throttle body unit.
Tore the regulator out and removed the existing spring, which was new a year ago, and compared it to the one I purchased off of Amazon that advertised for 12 to 14 psi. It's obviously taller and a little bit thicker. I installed it and replaced the gasket and turned the ignition on (did not start it) and it showed 12 psi. I turnes the motor over and it started right away and ran almost perfectly. As it started to heat up, about 20 minutes later, I found that it was starting to surge again unfortunately.
I took it a for a spin and it ran like sh*t. Crawled back under the hood and did some more digging around. I happened, by just pure luck, to look at the driver side fuel injector and there was gasoline pooling on the top of it. Upon closer examination I saw that about every two or three seconds and additional drop of gas fell into the throttle body port on the driver side. I'm guessing whenever that extra gas dropped in the RPMs spiked upward and then fell back down again until the next extra drop of gas fill in. So I took the regulator off again and remove the driver side fuel injector. I replaced it with one of the old injectors. I put on a new filter and o-ring and it snapped right in place. I started the engine and it ran almost perfect with no surging. It's been running out for 20 minutes with no surging and a steady 740 rpms. I took it for a spin and it is running about 85%. I think when I get my new throttle body rebuild kit from RockAuto tomorrow I'm going to replace the passenger side injector with the old injector. All of this freaking work and it was a bad injector which was a GM Genuine injector. I didn't put in a POS aftermarket injector. I'm I'm saying it's 90% fixed. I'll know more this weekend
I hope you found the problem so you can put that headache behind you.
Would love to find one of those washers...wouldn't mind 13psiEither way, that slight bump in fuel pressure should help, not hurt. You can also tweak it a bit with a thin washer or similar. Around here, people used to swear they all ran better at 13
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