tazmaniac_37752

My 91 4runner is hard to start and has no power, almost like it is out of time. I have checked the timeing with a light and by the marks and it is spot on, I their are no tell tell signs of a vaccum leak, the plugs are new, I pulled the plug wires one at a time while it was running and all cylinders seem to be fireing or atleast it makes a difference when each wire is removed! I hooked a rubber line to the vaccume line on the EGR valve and applied vaccume manually and it killed the engine, made sure it's not cross wired, anyone got any other ideas?

j2the-e

When did this start? Just all of a sudden? After doing work? Bought it that way? Is the distributor hold down bolt somewhere near the center of the slot?

tazmaniac_37752

when I bought they had changed the driver side head and couldnt get it running, They didnt have the pipes to the map sensor/ breather box hooked up, I hooked those up and it will run now. The distributor hold down bolt is just a little bit counter clockwise of center. To me it sounds and acts like it is running on 3 cylinders but as I said I pulled the wires and it makes a noticable difference when each wire is removed and then put back!

j2the-e

Maybe the timing belt is off a tooth. Also check that the timing changes when the jumper wire is hooked up vs not hooked up.

tazmaniac_37752

I checked the belt 3 er 4 times just to be sure and it is correct, i put the jumper in when i set the timeing but i didnt take it out to see if it changed while i still had the light on it, i will do that and let youns know thanks!

tazmaniac_37752

I checked on the timeing with and without the jumper and it made no difference! What does this mean?

j2the-e

It most likely means there is no idle signal from the tps. You can advance the timing to 20-25° and see how it runs. I wouldn't recommend leaving it there though, only for testing purposes. Do some searches on inspecting, adjusting, replacing the throttle position sensor. Base timing can only be set properly when the ecu sees the idl signal from the tps.

tazmaniac_37752

Ok thanks, I'll check it out and let ya know!

tazmaniac_37752

Finally got around to testing the TPS and it is adjusted correctly and test to be working, what do youns suggest I try next?

DeathCougar

iTrader: (23)

Yank it out and put in a 3.4?

j2the-e

I agree. Perhaps the engine is running normally and you just aren't used to how gutless they are. Have you driven one before?

bone collector

Have you checked for engine codes? Even if the light isn't on, the computer will store them. Check those.

tazmaniac_37752

Nope I haven't driven one before it maybe just gutless like one of ya said. I have also been told that a 3.4 wont fit. And nope I havent checked the codes because my book dosrnt tell me which terminals to jumper for the self diagnostics!

DeathCougar

iTrader: (23)

3.4 Won't fit? Who told you that nonsense. There are countless threads here on YT, as well as vehicles across the country that have 3.4's in them. It is a very popular swap.

Self diagnostic you jumper E1 and TE1 terminals, then start counting. Several threads here on that as well.

tazmaniac_37752

The owner of a local salvage yard checked for me because i asked him about a 3.0 and all he had was a 3.4. I myself haven't had any dealings with a V6 toyota engine. All of my dealings have been with 4 cylinders, mostly with the 20's and 22's.

Gamefreakgc

When you say it acts like it is running on 3 cylinders, what do you mean? Just lack of power or does the engine wobble side-to-side? They may have messed up the valves real bad when they changed the head and you're getting no compression. A compression check would let you know.

tazmaniac_37752

I finally got it to self diagnose and the code it showed was 43. someone suggested that they coulda messed up the valves so I borrowed a compression tester today and am gonna try the check that tomorrow! What I ment by seems like it's missing on 3 cylinders is that it shakes like it is missing, it sounds like it's missing on 3, and it has no power. However when i leave it idleing and remove the plug wires one at a time it makes a significant difference in the engine.

bone collector

http://personal.utulsa.edu/~nathan-b...26diagnosi.pdf

code 43 is something in the starter signal

Gamefreakgc

Yeah, it sounds like that compression check is going to tell you what you already are thinking. Those cylinders aren't holding pressure, most likely the valves are burnt or out of adjustment.

I had a similar issue a year ago. I did a valve adjustment and it was like I had a new engine again, ran super smooth and a lot more power, especially in low RPM's.

tazmaniac_37752

You just told me something that if it is so, makes me quite happy. If the engine has adjustable valves i'm prety sure thats going to be the problem. My haynes manual seems to be telling me everything except what I need to know.I will still do the compression check before I pull the intake and valve covers. This would also explain what the guy that I bought it from was saying that it ran good before he had the head changed it just had alotta noise in the driver side head. Then hasn't ran right sense! Straight up I am a toyota patriot but like I said I have only ever worked on the 4 cylinder engines. Ive owned only sold in order to get newer versions 4 trucks and one car.