rburn

1988 4runner 22re DLX man. trans.

I feel I've done adequate on-line searching and tune-up procedures to seek out the problem, so I'm posting here to get some feedback.

There seems to be a slight hesitation, fairly rhythmic, when I'm trying to maintain a speed like 25mph or 30mph. Nothing drastic, no major surges or power loss, mpg normal (like 19-21). I just get a fluctuation in rpm. Kind of like a hesitation.

Don't have any error codes. I've checked plugs and wires, new cap and rotor, ignition timing at 5 deg. BTDC, new pcv, new vacuum lines.

Checked out the 4crawler info on TPS. Inserting the jump from TE1 and E1 to do my timing, and the motor did idle "slightly" lower, so I guess that tells me the TPS is working at idle. I'm having difficulty getting to the lever and screw to get my feeler gauges in there. Before I disassemble the TB (which looks OK through the butterfly) I thought I would jump on here. I did check the Ohm resistance of the TPS as it sits. VTA-ED2 is good (300 ohms - cheap ohmeter, might not be calibrated properly, but it registers), but I'm not registering anything with WOT. The TPS was slightly loose - unplugging it did move it slightly, but the problem is identical with the slight movement of the TPS, and with the TPS plug disconnected. Maybe just a dead spot?

I'll remove the throttle body and do a full test maybe later today (with a better multi-meter) - Any suggestions out there?

rburn

TPS checked out fine, actually. It seems to be a vacuum leak.

Thanks for everyone's help. Couldn't have done it w/o ya!