sdoolin

1987 22RE short block with new head, 286 "RV" Cam, and all else stock installed into a 1988 4Runner.

The fuel injectors, the TPS, all of the vacuum switches, the knock sensor, the MAF, the ECU and everything else are from the 88. New cap, rotor, wires and plugs.

MAF indexed to be 3 teeth "richer" than stock settings. This did make a difference in how well the engine pullled, but had no effect on the st-st-st-stuttering.

The thing runs sweet and pulls well so long as you have your foot in it. Also idles well. At constant, small throttle openings the engine will surge and st-st-st-stutter. Also will hunt for an idle speed when the brakes are first applied.

I have been driving it this way since the engine swap was done 200 miles ago. I _cannot_ figure out what is up with it and am ready to shoot something (maybe the doner 1987 4Runner).

Anyone have any ideas about the st-st-st-stutter?

black diamond

i would start by checking TPS, may need to be cleaned and or adjusted

de6w6it

I had a similar issue in my other rig. I ended up changing the ECT and the AFM, as they were not within spec. Also, if you say it runs better with your foot in it, I would think maybe the timing is too advanced for when it is lower in the rpm range.

sdoolin

The TPS is fine, and the timing is set at factory. I checked the TPS and I set the timing. Have also checked, re-checked, and re-re-checked vacuum lines and connections. I have a good running 87 runner to compare vaccuum lines with. So I don't believe that is the problem.

Anyone else have any ideas?

gametom

i have a similar problem but when mine's cold it's fine

Perdurable

umm kinda sounds like my truck it would run fine when it was first started but when she warmed up and idled down it would start to rev up and then sound like it stalled for half a sec then rev back up over and over if your not touching the gas so i was informed that with older trucks nasty crap in the tank gos into the injectors (makes sense) so put a bottle of fuel injector cleaner in it and half a tank later she was fine but im not sure if thats what your describing but just trying to help

Targetnut

I would suggest to test the output voltage from the airflow meter (AFM).

It should change in a smooth sweep with the movement of the flap door.

It is possible that you may have contaminated or otherwise damaged the circuit while you were adjusting it.

the symptom you describe could be caused by a problem with the AFM

gametom

i know my injectors are clean

sdoolin

Yep, mine too, I had them serviced. Also know that I didn't contaminate the MAF while making the adjustment - I was WAY (WAY) careful (but thanks for the idea).

So it doen't seem like anyone on these forums has run into this and managed to resolve it? That is fascinating. I figure it has something to do with the cam - but have trouble believing that......

azcoma

I have the same issue with my '86 22re built pretty much the same as yours. RV cam/ bored .020" NWOR header. It Studders and misses at partial throttle 1800rpm- 2800rpm and a little at idle. I disconnected the O2 sensor and the miss went away. Currently running a NWOR header and will be replacing it with a LC engineering unit with the O2 bung down at the collector instead of hanging off the #2 cylinder runner. hope this will finally clear this up!!!

sloppy85toy

mine has a stutter right after it warms up with my foot barely on the throttle kind of like when u side hill with a carb truck.i cant figure it out either.and like u said it still has plenty of power.wierd.if u find out what it is pm me and if i do ill pm u.i put a new head on mine but it was several months later when it started this im thinking its a fuel problem.not bad fuel but some how not enough fuel.

mikilu88

My 4runner has a new headgasket. Also i have a engnbldr cam i think the 268. what it does is that if i am revving on neutral then it hits the 2000rpms it goes down to 1500 and then revs up again to 2000rpms and just keeps on going like that. My 02 sensor is dead. I checkd the code for it on the diagnosis box and i ma getting code 25 and 26 i believe and i took out the o2 sensor to the the exchange and i sounded like broken inside (i was going to replace it but got a different model). If i step on the break and i rev it to 1300 rpm it will fall down to 1000rpm.

muddpigg

iTrader: (1)

Check:
computer codes
vacuum lines
EGR
grounds


281* sounds like a pretty radical cam, perhaps your idle is too low.

As for RPM's dropping when braking; it's a safety feature.

As for moving the O2 sensor further down the exhuast flow; caution those things work at a certain temp range.

Guys not not trying to sound like a jerk, but get the FSM. Not Haynes or Chilton there not the same as the FSM.

sloppy85toy

bump!

scuba

same problem

im basically stumped