Fuel smell is gone! Fixing that hose did the trick.

Unfortunately, the driveability issues returned last night. It was 70 degrees Fahrenheit on my drive home last night, and the car was back to bogging down under WOT. Temps were in the 40's this morning, and the car ran fine. Should I still try to check the fuel pressure under WOT, or should I be looking at something else altogether?

In summary, the problem only occurs under WOT. The warmer it is outside, the worse the problem gets. The cooler it is outside, the better the car runs.

 

" . . . and swapped the two wires that attach to the center of the the gas tank (on the side facing the trunk)"

Why did you do this? What happens if you put them back to where they were?

Is the throttle plate and bore clean? Plugs? Any codes?

 

I'll try swapping them back. I didn't notice a difference either way. I just thought I'd give it a try, as it was possible they could have been put on in the reverse order.

Is it possible the plugs were fouled during the numerous times the shop cycled the key checking the fuel pressure after one of the pumps they installed failed immediately? The car was started about a dozen times during that period, as well. Each time it ran for a few seconds, then stalled, as the new primary pump I supplied was faulty.

The only code that appears is the P0400 that has been there since the day I bought the car.

Throttle plate is clean, as I clean it along with the intake tube a couple times a month. I cleaned all of that along with the MAF sensor a few days ago.

 

I've speculated on quite a few things. Here's what I know:

When the outside temperature is below 60 degrees, the car runs almost normally, except for the random hestitation here or there. Above 60 degrees, the engine bogs down under WOT, and clears up upon repeatedly stomping and releasing the gas pedal.

Anything around 3/4 throttle or less, and the car runs perfectly throughout the RPM range, regardless of outside temperature.

The fuel smell was a broken hose at the canister to the left of the gas tank, which has been fixed and is no longer an issue.

The fuel tank is not quite installed properly, with the filler neck sticking up just a little too high.

The pain in the butt fuel lines apparently were broken during tank removal, and were replaced by the repair shop.

I have a P0400 trouble code, which has been there since I bought the car. Never affected performance before, but may be an issue now?

The car ran perfectly before the primary fuel pump failed. It has not run correctly since I had both pumps replaced.

I used Onix fuel pumps, as I had to get it back on the road as cheap as possible.

I have yet to check the fuel pressure under WOT. I was going to bring it back to the shop, but upon discovering that they broke the hose that I fixed yesterday, I'm pretty much done with them. I still owe $100 on the repair, and I'm not paying it, as I'm sure the broken canister and kinked hose are going to cost much more than that. As a result, I'm sure they're not going to be eager to check the fuel pressure for me... lol

 

Usually a bad fuel pump would run lean and would not foul plugs. what I THINK you proved switching wires may be important, though. It would seem both pumps are performing the same, so your problem may well be the power supply to the secondary pump. But check the pressure under WOT- that's next. Then you need to figure out how to test the secondary supply. I would rig a 12 volt test lamp to the circuit where I could see it under WOT-

 

The wires that I switched weren't for the fuel pumps. They were on the side of the tank, right in the middle, on the side that faces you when you're in the trunk. What is that, anyway? A purge valve or a level sensor? They were just two single wires that each pushed onto a spade terminal. I'll switch them back before I leave work today, and see if anything happens.

 

I just took a closer look at the diagram that Sean B. provided, and the wires that I swapped were for the fuel level sender. Gas gauge works the same either way, so I will assume that they can go on either way.

 

How did this work out?

 

Fuel smell has not returned, so that's a good thing, but the performance issue is still there. I'm probably just going to leave well enough alone, for now, as it is all I have to drive and I can't leave it at the shop for another two weeks.

It's up for sale right now, due to the need for a car I can drive this winter. If it doesn't sell before the first snow hits, I'll keep it and park it for the winter.

 

Update...

I am a moron.

I just now finally decided to dump some dry gas (Iso-Heat) in the tank, when I only had 3 or 4 gallons of gas in the tank. The car is running perfectly again. The shop must have gotten some water in the tank somehow.

I wish I would've tried the dry gas sooner...