yotaman35

I am hoping that some of you fellow Toyota lovers can help me. I have an 87 Toyota 4runner with a 22re engine. I bought the 4runner about 4 months ago and have rebuilt the engine myself. The engine sounds good and runs good all except at cruising speed it is cutting out. It doesnt do it on acceleration or idle, only at that sweet spot when driving that im trying to keep a steady speed. Also while it is cutting out on me I notice that the rpm's are not affected. When its really cold outside it doesnt seem to do it as bad if at all. If anyone has any ideas of what my trouble may be I would appreciate your help, thank you.

yotaman35

Again any feedback would be greatly appreciated, thank you.

JonnyBoy

You rebuilt all the mechanical stuff, but what about the electrical? Basic tune up with new wires, plugs, timed properly with a timing light? What efi parts have you tested so far?
My gut says throttle position sensor, but I don't have lots of experience troubleshooting efi engines without consulting here, usually and just researching symptoms. If you give more details about what you've done so far, others with more knowledge will probably chime in.

Buck87

I have the exact same situation on my rebuilt 22re except that I would describe it as a miss not a cut out at about 2800rpm to 3200rpm (cruising speed). I suspect the TPS. I have lived with it so far. I tested the TPS according to the FSM on the vehicle but it was a bit awkward. I next plan on removing the throttle body and cleaning it, changing the o-ring on the idle adjusting screw, all new vacuum hoses and doing a more accurate test of the TPS on the bench.
How is your fuel pressure?

Co_94_PU

iTrader: (-1)

That is a odd (to me) description. Is it sputtering/missing, clutch slip(should be an rpm diff), or just a lack of power?

That sweet spot.. Is where the TPS and AFM wear out, test them!

yotaman35

I rebuilt the engine, new rings, bearings, timing chain, oil pump, water pump, belts. I put newvalve seals in the head. i replaced plugs, plug wires, and distributor cap and rotor. when driving and trying to hold speed it cuts out as if it stops firing, just a constant jerk or miss. i also did replace one valve because one of the exhaust valves was broken, the whole side was broken off. I did not lapp the valve but did turn the head upside down and poured gas in the valve bowl and let sit for 20 minutes without it leaking any by, so im pretty sure it is seating well. besides, the valve was broken and never did this so im thinking its not that anyways. it doesnt do it all the time, seems like it doesnt do it when its really cold outside. The only sensor i replaced was oxygen sensor, i didnt touch anyother electrical. i also replaced clutch, pressure plate, pilot and throwout bearings. thank you guys for your help...i will try tps but not sure what afm is if you could help me with that. thank you guys for your help.

That sweet spot.. Is where the TPS and AFM wear out, test them![/QUOTE]

Buck87

AFM is the Air Flow Meter and is on top of the air filter. I have one for sale because I did not read my meter correctly and bought one that I did not need when I tried to solve my problem. Do you have a Factory Service Manuel? Check out these links. They explain the procedure very well.
http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml
http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml

Buck87

How many miles on the rebuild?
If you have enough miles to break in the rings (500 mi) please check the compression and let us know what they are.

yotaman35

Thank you for the links, i will start with the tps. The engine has close to 100 miles on it since the rebuild. it will probably be this weekend before i get a chance to check the tps or afm but i will for sure let you know. Thank you for your help.

yotaman35

Ok guys...i solved my problem with the cutting out. I decided to replace the ignition coil and while i was at it the plugs as well. i dont know if it was the coil or not but the number for plug had zero gap. it runs great now. every now and.then when its just sitting at idle the rpm will all of a sudden drop almost killing engine but will immediatly jump back up to normal. anyways always something. Thanks all of you for the help. I love this forum.

yotaman35

Sorry....i meant number four plug...

Co_94_PU

iTrader: (-1)

Check all your new coil connections make sure they are clean and tight, since that is what has been altered last worked on. Bummer about the spark plug it was most likely your major issue, this happens when you drop them most often. if you can get your hands on an inspection camera it would be a good idea to look inside that cylinder to make sure there isn't anything funny going on, eg piston contact.