85toy

1987 4runner 22re 5spd everything is stock.

ive had this problem since i bought the truck. if accelerate hard it runs fine but if i just cruise it sputters and jerks quite a bit and if i am on the gas and then let off the gas it will backfire.

things ive done to try and fix it.

new and properly adjusted TPS
AFM
ECU
coolent temp sensor
full tune up
o2 sensor
checked wiring to ECU

im not getting any codes

I need to smog and register this thing in june and I have no idea what else to do. Please help me YT

EDIT: forgot to mention it runs fine when the TPS is bypassed.
also when the TPS is not bypassed, as in everything hooked up, the tach jumps around alot but when the TPS is bypassed it acts normally.

85toy

no insight on this?

SoCal4Running

Hate to say it but sounds like a TPS issue. Does it do it at a specific rpm no matter the gear (say 2000 to 2200 only)?

85toy

nope, anything above idle, i should say that it runs fine at idle but if you give it any gas at all it starts running bad, my uncle has another tps i might throw in there just to make sure.

sb5walker

When you floor it, I think it runs in open loop, not using sensors to calibrate mixture/timing, so that kind of makes sense.

The jumping tach sounds like the igniter is involved since the tach lead comes from there: either a bad igniter or more likely the ground/wiring to the igniter, possibly the hall sensor (signal coil) in the distrib or the ignition coil.

Disconnect the coil and check the resistance of both the primary circuit (pos to neg terminal) and secondary circuit (pos to high-volt cable) per fsm spec. Clean up the igniter ground. Check resistance of signal coil in distrib. Try to wiggle the distrib shaft side-to-side while you're in there. Should have almost no play. Check wiring/connections between distrib & igniter, between ignition coil & igniter, and especially between igniter & ecu (igt, igf & ne) It sounds like a bad connection/ground, or possibly a short. Check that terminal E1 on ecu has a solid connection to chassis ground, and verify the engine grounds are solid.

85toy

thanks ill check that out tomorrow, luckly i have tomorrow off work so ill have time to mess with it. i dont think its the igniter itself but a bad connection is very possible.

another thing i forgot is that i have replaced the distributor.
but ill check all the connections tomorrow.

tried4x2signN

x2, Check all your grounds...

SoCal4Running

Off a tooth?

Moonfish

Checking the grounds is wise. I'd also verify the timing was set with the diagnostic jumper in place. When you put the jumper in, the idle should change. Maybe the TPS has to be set before you do it also? It's been a while but I trailed and errored it about 4 times before getting it right.

85toy

im getting code 3 on my 22re, vehicle is 1987 4runner. should i replace my coil?

85toy

guess no one has ever had a code 3 before hmm.

code 3 is ignition signal if anyone cares.

vital22re

iTrader: (2)

maybe the distributer?

85toy

already replaced that, but thanks for the input

DeathCougar

iTrader: (23)

Start with what the problem of the vehicle is, what you have tested, and what you have replaced.

You can't just start a thread saying "Code 3, please fix my rig"

85toy

https://www.yotatech.com/forums/f116...ly-bad-211099/

DeathCougar

iTrader: (23)

Combining the threads

85toy

Thanks !

85toy

bumppppp

sb5walker

You haven't posted any results of what you checked. Did you check resistance of both circuits of the coil? What were they? How about the signal coil? How is the wiring and how are the connectors? Corroded? Did you clean up the igniter ground & verify it? How many ohms between igniter ground (probably a solid brown wire) and the neg batt post? How many ohms between that wire on the igniter & its place of connection to the ecu (terminal E1)? How many ohms between the chassis & neg batt post? Between the engine & neg batt post?

The fsm says code 3 is no signal from IGF 4 times in succession. IGF is one of the four wires between the ecu and igniter - it's the black wire with yellow stripe. It's the ignition confirmation signal from the igniter to the ecu. If the ecu doesn't receive it, it stops firing the injectors, which certainly could cause your bad running. A code 3 could be caused by a bad connection on the IFG wire between the igniter and ecu, so I would check it. You need connect a jumper wire to one end of IGF and lead it to the other end where you can check ohms between the other end of IGF & the jumper. If you don't have a jumper wire, a jumper cable with clean clamps will do the trick. If you don't have back-probe adapters for your multimeter test leads, you can connect to ecu terminals by pushing a sewing needle into the connector and holding the test leads firmly against it.

If the IGF wire is okay, could be a bad igniter, but also could be something preventing a good spark, such as a bad coil or bad connection/ground. Check the ohms on the cable from coil to distrib. Or the power supply to the coil/igniter could be intermittent. Check the positive lead of the coil for solid, unwavering power when ignition is on. If it's intermittent, probably a bad efi main relay.

While you're checking IGF, may as well check IGT, the spark triggering signal from ecu to igniter (black wire white stripe) and NE, the crank position signal from the signal coil, through the igniter to the ecu (black wire red stripe).

Let us know what you've checked and what you found - we need info to help you.

swampfox

i had a nissan that ran fine with no tach,but if the tach worked the truck ran like crap and would die.the po had replaced about everything you have plus the coils. it turned out to be bad grounds. i cleaned every ground under the hood that i could find, and finally hit the right one.