throttle body/ fuel pump

[morris69]

So here we go.... LS3 CRATE ENGINE 1500 MILES/ 6SPEED- 1969 CAMARO.... for quite some time ( previous ls1 and another crate engine ls3) I've been having this backfiring issue and stuttering at high speeds. (No other issues) I change the computer and harness with a new tune and the back firing and stuttering was gone. But now I have this issue of the throttle body shutting off at wide open throttle. I drove the car 80 to 90 miles and hour for about an hour straight. And as soon as I stepped on the gas I noticed the the pedal go out "clutchy" similar to how a clutch feels but gas was still being produced. I down shifted and limped off of the freeway. I turned the car off and turned it back on and it was fine. I drove home with no problem, as soon as I opened it up full throttle the pedal went "clutchy" again
I took the car back to the shop. 80-90 miles for an hour no problem. As soon as I go full throttle it did it again. We took the pipe off that goes in front of the throttle body and Noticed that the throttle body was only opening up at half throttle. The tuner put the car on a dyno and the car threw some throttle body codes. We put a different throttle body on and We figured we fixed the problem because wide open throttle no problem. So as I'm driving home the car suddenly loses all power to the fuel pump. The pedal goes "clutchy" but instead of me throwing in a lower gear to limp off the car is not giving me any gas to power off the exit.( the car still was powered on) I tried to turn the car on figuring it was the throttle body but I wasn't getting any power to the fuel pump. I checked the fuel fuse no issue. I Checked the fuses under the dash and they had power. I took the gas tank off on The side of the freeway and took the fuel pump out and it had power. Toyed with the wires near the tank maybe bad ground everything look Ok. Buttoned everything back up and the car ran fine 80-90 for an hour with traffic thrown in the mix. As I was getting off the freeway. I decided to step on the gas full throttle. And it did the same thing that it did before "clutchy" pedal. turned off the car turn it back on GOOD.*
Went home plugged the car up and it read code p2030 fuel pump relay wire/switch. I turned the code off and drove it around the block. Full open throttle NO issues. Called the mech. And told him what had happened. He said as soon as the fuel pump gets hot it's gonna "do the throttle thing again". Sure nuff. He was right... read some fourms on lat-g and pro-touring. So these are my facts.
1. Boush 044 fuel pump 4 months old.
2. This never happened until I changed the computer and harness
3. Stock crate LS3 with stock drive by wire pedal.*
4. Ricks stainless tank
What I was told it could be.
1. Fuel pump.
2. Throttle by wire pedal
3. Install a fuel relay switch.
4. Connect a ground from the battery to the block.
5. Something in the tune.



I know it's a long post. But those are the facts
HELP PLEASE??????

[MonzaRacer]

Wait you DONT have your battery grounded to block?
I mean if its in trunk, you should have a large 00 gauge wire, crimped and soldered to terminal bolted too clean frame ground coated with dielectric grease and at least a pair if not 4 heavy braided stainless or 00 crimped/soldered grounds from block too frame. I used 00 battery cable from battery straight up too starter solenoid on firewall on my Old Monza, I ran battery grounds through cut off switch then too frame rail. I did have a live battery cable from front too back. In later incarnations I may incorporate a solenoid in back too keep big cable dead except in start mode. BUT I did what I did from using what I had at time.
Grounding also from block to dash frames if thats where you grounded your computer.
Also EVERY connection needs to be crimped ,soldered AND then some sort of insulation. I use shrink and seal tubing, this glues its self to prevent any connection forming a water tight seal.
I almost NEVER crimp only, a connection.
Now you might have damaged the computer so after looking over your wiring connections dont forget it might have been damaged. Tap test with plastic screwdriver handle.

Oh yeah you did say its Camaro/Fbody, dont forget to add several ground straps from subframe to actual unibody.

[morris69]

Thank you very much. I'm going to triple check every ground and ground every thing u said this week.

Could a bad ground cause this issue?