LNFwagonSS

Went for a drive the other night and did a 2nd-3rd gear pull. It pulled like it always has but shortly after the pull I started feeling vibrations from the engine and when I would push clutch in rpms would dip pretty low. Maybe 400-500rpm then come back up and would fluctuate between 900-1200. Headed home to check it out and the car was gradually starting to run better. At a stop, while idling, I could hear the fuel pump ticking super fast abnormally. The CEL did not illuminate but I did find code P0267 was stored. Which means "Injector 3 control circuit Low voltage". Cleared the code and next day went for a drive to see if it acted differently. The rpms were steady but the HPFP still randomly freaks out and starts ticking rapidly then goes away, which is not normal. Here is a list of codes that are related:



I will be checking the harness thoroughly and possibly adding some seafoam to fuel if needed but due to the nature of this code and related codes I am wondering if there is any other possible related electrical faults causing this. The only other possibilities I can think of are either
1. Weak battery. I actually had to jump start it after pulling the code as I was monitoring fuel pressure after shut down amongst other things. Key was in on position for maybe 10-15 minutes. And the fuel pressure rose up to about 2490 after shut down then started dropping pressure slowly after about 10 minutes. After I jumped the battery, I let it idle for a minute to charge and then shut down. Fuel pressure was then at 400-450ish. Not sure what's going on there..
2. Wot box. I had to tap into injector ciruit for wot box which I will be checking also.
Just want to gather ideas for now. Not much info around here about injector control circuit related issues.

SR Tech

iTrader: (2)

I'd be willing to bet its the wot box

LNFwagonSS

Wot box internally?

LNFwagonSS

Completely forgot that the wot box injector control circuit was spliced into injector control #3 circuit at the ecm. looks like i need to route the wiring a little differently and away from the natural bend of the harness plug. These wires are friggen tiny! Wire must have been hanging on by a thread because it just came right off of solder joint when I touched it.

firehawk618

iTrader: (2)

Glad you found your issue so quickly.

LNFwagonSS

Thanks. Me too. I forgot the tach signal for the wot box was on this specific wire. I'm just glad I was able to find the stored code right away. I tried looking for an alternate wire for tach signal (because the smaller low voltage wires a super brittle with only 7 strands) but was unable. Seems any other tach signal must come from a tach driver.