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View Full Version : Throttle Body/ Fuel Pump


morris69
07-30-2014, 07:39 PM
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.

HELP PLEASE😨😨😨😨😨😨

Che70velle
07-31-2014, 10:20 AM
Are you running the inline 044 pump, or the in tank 044 pump?

morris69
07-31-2014, 12:30 PM
The pump is inside the tank.

OBeer-WAN-Kenobi
07-31-2014, 01:44 PM
Have you checked the fuel pump Relay? I'd start by replacing that.

Do you have any way to check fuel pressure? If your pump is on it's way out or defective it might be drawing too much amperage (possibly frying your relay) and not producing adequate fuel to the injectors causing the PCM to fault.

Just some guesses, but a relay is cheap to try.

morris69
08-01-2014, 10:10 AM
I checked the relay when I took out the tank. It was still good

Che70velle
08-01-2014, 11:22 PM
I've been thinking about this all day. I don't understand what your pedal is doing. Are you saying that it gets harder to push? This is a DBW pedal, correct? What is surprising to me is that the mechanic you mentioned in your first post, stated that the pedal would do this again as soon as the pump got hot...and he was right. Did he give you a synopsis as to why the pedal is doing this?
The unfortunate thing for you is that it really could be anything listed in your first post. I had the same code issue once, but I didn't have my pump wired through the computer. It was straight wired to a switch, as we were simply trying to test fire my engine during mock up. Perhaps your tuner could do a diagnostics check through his equipment? I would think that his stuff would show more data than a handheld unit? I don't recommend just throwing parts at it. That seems to never work out for anybody, except the parts store.
This ALMOST sounds like a ground issue...

morris69
08-02-2014, 02:16 PM
Yes its a dbw. The pedal feels like a clutch. I can press down on it and it feels normal but there is no response. Not like breaks when they go soft. I shut the car off for about a min. Then it's back to reg. Driving until I go full throttle. Then it does it again.
My mech. Feels it's the fuel pump. When I took it to the tuner he it read a throttle body code. We fixed that and he said the same thing as far as it being a ground issue. He said 4gen cars. Need a ground from the battery to the block. So before I buy anything. I'm going to go thru all my grounds. Each one by one.ill keep you posted thanks bro

morris69
08-02-2014, 02:23 PM
One more thing. This never happened until I installed the new computer and harness.

spode
08-02-2014, 09:13 PM
Kinda sounds like one of those Gold vs Silver blade issues. Need to have the right computer for the throttle body.

morris69
08-03-2014, 12:47 PM
That's interesting u said that. Because I ordered a new harness. And the mech. Gave me what he told me was a brand new computer from his shop. I had a gold blade on the motor when I brought it in. And we changed it to a silver blade. But I'm definitely going to look into what type of computer and throttle body. That was very helpful. Thanks.