Thought some of you might find this interesting...
03-21-2009, 08:55 AM
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Thought some of you might find this interesting... I work for a shop that runs cars at the dyno pretty frequently, so I had a chance to run my recently purchased '93 T/A there a couple times. I ran it basically right after I bought it, when it was running pretty weak and had a high end mis. It showed the car leaning way out pretty much after 1500 rpms until it pegged the chart at 3800. After that single run I decided to quit putting off the fuel pump replacement as I figured that's where my problem was for sure. The dyno run peaked at 211 hp at the rear wheels and the line looked like I was trying to sign my name with my left hand...I'll scan a copy of the sheet/run and post it Monday.
I replaced the pump...finding the one that whoever replaced it before me had replaced it with a Honda Civic pump or something awfully cute and tiny compared to the Walbro replacement pump I put back in. Went to the dyno again and it was night and day. The run had a clear smooth power line/run, the air/fuel mixture stayed below 12 the whole time...mostly ran rich at mid 10-11, and the peak power at the wheels was 252 hp...forget the torque number but it was equally acceptable for a stock 118K car.
The moral of this story, even though the previous owner says they replaced the fuel pump recently, never assume that just because parts are new that they are good. Case and point, the pump was new, but was the wrong size and could have cost a lot of money in unnecessary replacement parts of ignition or fuel components had I decided to trust the pump was not the issue. Anyway, though some of you might get a kick out of that...I'll post the before and after dyno run sheet copy Monday or so when I get it from work and bring it home to scan.
I replaced the pump...finding the one that whoever replaced it before me had replaced it with a Honda Civic pump or something awfully cute and tiny compared to the Walbro replacement pump I put back in. Went to the dyno again and it was night and day. The run had a clear smooth power line/run, the air/fuel mixture stayed below 12 the whole time...mostly ran rich at mid 10-11, and the peak power at the wheels was 252 hp...forget the torque number but it was equally acceptable for a stock 118K car.
The moral of this story, even though the previous owner says they replaced the fuel pump recently, never assume that just because parts are new that they are good. Case and point, the pump was new, but was the wrong size and could have cost a lot of money in unnecessary replacement parts of ignition or fuel components had I decided to trust the pump was not the issue. Anyway, though some of you might get a kick out of that...I'll post the before and after dyno run sheet copy Monday or so when I get it from work and bring it home to scan.
03-21-2009, 04:53 PM
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Thats not a bad dyno run. And as you said night and day with the fuel pump and good thing you figured that out before looking into any other issues that it could've been. I went through a similar issue but my fuel pump was just bad from running out of gas. lol. no good.
