won't rev past 4500

[sts76]

91 240sx with ka24de. rebuilt engine with great compression. No ECU codes. Cleaned MAF, checked MAF with multimeter, checked TPS with multimeter. Checked all vaccuum lines. Checked cam timing.

Engine starts and idles fine. Does not pull very well through the rev range and cuts out completely between 4500 and 4800 rpm. Will pull past this point if done at part throttle. Cruises nicely at 85 mph, just doesn't accelerate worth a crap.

Has anybody experienced this and have specific suggestions? The next step seems to be fuel filter. I have a feeling that is not it though. I doubt the fuel filter would clog up while the engine was being rebuilt. I'm sure it's something I did, just don't know what. I have checked and rechecked every electrical connection and vaccuum line.

Thanks

[drjohn]

Fuel filter would be a good place to check first. You can have good pressure but not enough volume. 91 I believe has 2 connections at the tps. 1 is hard contact,idle position and 1 is soft contact which gives throttle position to ecm. When checking this the center pin is common and the ends are signal. Check this with a anolog meter and as you open the throttle wide open watch the needle for any uneven movement when slowly opening and closing the throttle. Any deflection indicates a bad tps. The hard contact just needs to read on or closed with throttle closed and open curcuit with throttle opened just off idle.

[sts76]

changed fuel filter today. No change. Checked TPS with meter, but mine is digital. It was changing the reading, but I don't know if there is any uneven movement. The other 2 pins check OK.

[EZcheese15]

Also try checking the distributor. The infrared plate in the distributor can get dirty (or oily) and it will cause the car not to rev right. Or atleast the tach won't pick it up right. This *should* cause a check engine light though, but it might be worth checking.

You can check it by simply unbolting the cap on the distributor and looking at the plate.

[Chezedik]

What specs did you use to check your MAFS?

[sts76]

The specs in the FSM. checked fuel pressure today and it was 38psi at idle raising to over 40 when opening throttle. still no change. Tried revving in neutral with no load. Can ease revs up to about 6500 rpm. At that point it cuts out and drops to 4500 and starts surging between 4500 and 5500 with throttle held wide open.

[QuinGarcia]

what about exhaust system? clogged? how is your oil pressure? are hydraulic lifters bleeding down maybe? or pumping up? Just a shot in the dark, but probably not your problem.

[sts76]

Replaced cat with test pipe today. Still no change..

[sts76]

Gave up and took it to a shop. Diagnosis: cam timing. Even though the silver links were lined up with the dots the cams were not in the correct position. Got home tonight and set #1 to TDC. The links were 1 off the dots. Moved the cams 1 tooth each and TA-DAAA!! It's finally fixed.

[Gregs240]

Had same Problem w/ my '92 I replaced the plug wire and it fixed my problem. before you replace the plug wire check them. If they are cracked or have visible damage replace them.