ferchja

Just did a full engine repair to a 97 Civic EX Auto. with 130k. History: The original threw the #3 rod. So we pulled the engine and replaced the Y8 block with a used Y7. We swapped all the parts off the old engine to the new block.

When done the engine ran perfectly no issues. However after a week and pretty much straight after the repair, it is slow to accelerate from stop to Xmph. It mostly is tied to the engine RPMs. 500-3000rpm the engine feels like is trying to start in 3rd/4th gear. After 3000 it runs fine. All fluids are new, tranny is at the proper level.

Questions:
1) It threw a generic P0700 tranny code. Reset and waiting to see if it pops on again. Could the solenoids be bad? Seems odd after the swap for those all of a sudden to go bad.

2) It also threw a P0122 Throttle position sensor low voltage output. I hooked up the multimeter and the voltage level sent back to the ecu was in range (.04 at 0% throttle, to nearly 4.8V at full throttle) So sensor was fine. Could this be a MAP or Temp sensor issue?

3) It seems to work perfectly within the first 1-2 miles of driving then the acceleration goes away. as if the engine warming up causes something to go sour.

Like I said it feels like your are acclerating in 3rd gear from a stop. With the tranny in neutral the engine seems to lag a bit from 500 to 3000, but not to the extent as when the engine is under load.

Need help! Thanks in advance.

Jeremy

00Red_SiR

When you first start an engine up, it runs in open loop which bypasses certain sensors (usually the O2 for one) and then goes to closed loop after that and takes readings from all sensors when warmed up. Knowing exactly what sensors are ignored would possibly help track down the problem area. Also how does your engine timing look? When you pull away from a stop you said it feels like you take off in 3rd..what if you try to manually put the tranny in 1st from a stop does it improve at all?

ferchja

Only thing swapped was the short block. Took all the crap off the donor engine to the bare block then moved everything from the original engine to the donor. The only part we used of the donor engine was the block with oil pan.

ferchja

Timing is dead nuts on. The auto only has manual 2nd, 3rd, 4th. When you drop the throttle all the way it takes a second, but the car will accelerate more normally after it kicks down. But this could be related to 100% throttle puts some sensors into a open loop. Any guesses as to what sensor may be on the fritz. When at normal cruising the car seems fine. I am trying to rule out the tranny and see if I can get to the engine to trouble shoot.

Any advise will be considered.

Thanks

Jeremy

ferchja

Would a vacuum line cause slow acceleration? I thought those mostly effect your idle conditions. Could the PCV valve be bad, causing unnecessary back presure?

EE_Chris

The TPS should be measuring .45v - not .04v. This could be why you're getting a TPS low output voltage code.

ferchja

You are correct that was a misprint on my post it should have read .4V.