After putting the head back on after having it at the shop, the engine revs itself to about 2200 rpm let's off to about 1500 and repeats. Have no idea why it does this. Any help would be appreciated.
Engine revs itself.
- Thread starter shadowsX9
- Start date
Does it do this with the gas pedal held to the floor? If so your problem is TPS related. If not, pinch off the ISCV hose and see what happens.
Pinching the iacv hose didn't do anything. The biggest change is when we disconnect the tps sensor, the idles climbs until we plug it back in or shut the car off. Any ideas? Have swapped manifolds once already it's, had this same problem with 2 different tps sensors and 2 different iacv
Also, as it revs up vacuum goes to - 20, as it revs down it goes to - 10. When you're on the gas it drives fine. It just at no/very low throttle, it keeps surging
I have to say it - have you got the memo about the TPS report? Only we're putting these new cover sheets on. I'll make sure you get a copy of the memo.
Hoses to the pcv and accordion hose are good, haven't been able to find any cracks or splits in any vacuum lines or couplers or anything. Car is okay under load.
What's the smartass thing about the tps? Care to specify?
What's the smartass thing about the tps? Care to specify?
Pinching the ISCV didn't do anything? That doesn't strike you as odd? And it can't be a vacuum leak. Not as long as you have the stock AFM on the engine.
No, those vacuum reading are when the engine is revving by itself in neutral.
We didn't calibrate the tps. It's done this same thing with 2 different tps sensors on it. We didn't remove just the sensor. His intake manifold had a stripped hole, so we swapped on one of my spare upper manifolds with the iacv and throttle body/tps that was on it. So if it was a bad/miscalibrated tps, or bad iacv wouldn't the new intake manifold with other sensors have fixed it?
The biggest difference we've found between my good running car and his is when you disconnect the tps. On my car, the idle doesn't change. On his, it immediately starts revving up instead of fluctuating. We let it climb to 3.5k before we plugged it back in. Idle dropped back down and went back to fluctuating.
Also, when it's idling up and down on its own it goes to 21:1 on the wideband when the rpm is dropping. But again, under load when it's driving the afr readings are normal. 14.5-15.5 while part throttle cruising, ~10.5 under boost.
We didn't calibrate the tps. It's done this same thing with 2 different tps sensors on it. We didn't remove just the sensor. His intake manifold had a stripped hole, so we swapped on one of my spare upper manifolds with the iacv and throttle body/tps that was on it. So if it was a bad/miscalibrated tps, or bad iacv wouldn't the new intake manifold with other sensors have fixed it?
The biggest difference we've found between my good running car and his is when you disconnect the tps. On my car, the idle doesn't change. On his, it immediately starts revving up instead of fluctuating. We let it climb to 3.5k before we plugged it back in. Idle dropped back down and went back to fluctuating.
Also, when it's idling up and down on its own it goes to 21:1 on the wideband when the rpm is dropping. But again, under load when it's driving the afr readings are normal. 14.5-15.5 while part throttle cruising, ~10.5 under boost.