951 used 1/3 of a tank of gas to go 70 miles, bucks at part throttle
12-29-2004, 05:07 AM
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951 used 1/3 of a tank of gas to go 70 miles, bucks at part throttle
So...I haven't driven the 951 in about 3 months (no money and having another fun reliable car that gets 35 MPG on 87 octane fuel are the main reasons), but the clutch hydraulics went out on my MR2 last week so I decided to charge up the battery (completely dead) on the 951 yesterday so I could leave my house. I went out on a date tonight, and besides an intermittent problem I think is cold weather related (happened a couple of times last winter but went away) where flooring the car would cause the engine to die, the car worked marvelously.
Anyways, after dropping said female off at her house, I had a 30 mile return voyage home. Everything was working fine until I got up on the highway and was cruising at 75 or 80, and the engine started bucking every few seconds and black clouds of smoke would pop out of the exhaust. The car started to smell like a diesel truck too. The bucking got worst, and went to a "only 2 cylinders are firing" thing whenever the car was on part throttle. At low throttle or wide open throttle, the car ran proper, but the idle was a little low and irradic. Oh...When the car switched to the 2 cylinder part throttle thing, black smoke poured out of the exhaust.
On a 70 mile voyage, the indicator shows the car used more than 1/3 a tank of gas. I am guessing that black smoke is insane amounts of gasoline being dumped.
I am just going to make a guess...Throttle Position Sensor? The funny thing is that I bought a new one when I had this problem last winter, but I never installed it as the engine cutting out at WOT problem went away. Almost everything in the fuel injection system that would affect fueling problems had been rebuilt/replaced (injectors, FPR, damper, lines, etc.), so it seems like a fuel miscalculation by the computer. Any thoughts on this? I'll try putting the new TPS on tomorrow and see if that fixes it at all. Thanks for reading.
Anyways, after dropping said female off at her house, I had a 30 mile return voyage home. Everything was working fine until I got up on the highway and was cruising at 75 or 80, and the engine started bucking every few seconds and black clouds of smoke would pop out of the exhaust. The car started to smell like a diesel truck too. The bucking got worst, and went to a "only 2 cylinders are firing" thing whenever the car was on part throttle. At low throttle or wide open throttle, the car ran proper, but the idle was a little low and irradic. Oh...When the car switched to the 2 cylinder part throttle thing, black smoke poured out of the exhaust.
On a 70 mile voyage, the indicator shows the car used more than 1/3 a tank of gas. I am guessing that black smoke is insane amounts of gasoline being dumped.
I am just going to make a guess...Throttle Position Sensor? The funny thing is that I bought a new one when I had this problem last winter, but I never installed it as the engine cutting out at WOT problem went away. Almost everything in the fuel injection system that would affect fueling problems had been rebuilt/replaced (injectors, FPR, damper, lines, etc.), so it seems like a fuel miscalculation by the computer. Any thoughts on this? I'll try putting the new TPS on tomorrow and see if that fixes it at all. Thanks for reading.
12-29-2004, 07:19 AM
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Get a vacuum gauge and check the vacuum on the hose going to the FPR. You should be seeing 20 in.Hg at idle or so. If less vacum or zero vacuum, then that's your culprit, too much fuel pressure. Could also be the dampener, but most likely the FPR.
12-29-2004, 10:45 AM
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What he said. I had that happen to my early n/a. Drove me nuts. Ended up being a very small and otherwise unnoticeable split in the "Y" connector by the FPR / Dampener. Once that was fixed it ran like a new car.
12-29-2004, 05:18 PM
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You guys are geniuses. Indeed, the vacuum line coming from the rear of the motor to the front tee blew off of the tee and I was getting no vacuum/boost to the FPR and whatever else connects up there. A 3 mile trip to advance auto, $3 worth of thicker rubber vacuum line, $1 worth of plastic tees, and 5 minutes later, and the car runs like a champ again. THANK YOU!!!! I CAN LEAVE MY HOUSE AGAIN!!!!