causes of hesitation?

[gary]

motor is a stock 22r, carb'd, with headers...nothing special
hesitates very noticiably when you floor it...
changed plugs, distibutor cap and rotor, cleaned air filter, cleaned fuel filter, set the timing (0 with the vacuum lines plugged) and messed with the carb settings, including mixture...all to no avail...
can't see any fuel in the little glass window on the carb, pretty much ever...manual says it should be about half full...can't get it to fill...
any suggestions? truck needs to pass smog asap, and i want it running as well as possible for them...

[tre5]

fuel pump??

[JasonHutter]

Isn't your timing a little retarded. I think it is supposed to be 8 deg BTDC with the vacuum line plugged or a jumper wire or paper clip in the plug on the fender well. I don't have my Toyota book here, but I think that is what it should be. The only other thing would be that you might need to rebuild your carb....?

Jason

[JasonHutter]

I just found my Chiltons Manual and here is what it says about hesitation or stumble during acceleration.

1 Ignition timing incorrect.
2 Ignition system not operating properly.
3 Dirty or clogged carburetor or fuel ingector.
4 Low fuel pressure. Check for proper operation of the fuel pump and for restriction in the fuel filter and lines.
5 Carburetor out of adjustment.


Jason

[gary]

fuel pump is fairly new...might be worth switching, just in case

carb was rebuilt maybe 2 -3 yrs ago....think it'd need it again?

[gary]

does it say what correct timing is? my manual is a haynes, or something, and says refer to hood for the timing #...i dont have it anymore...called a few shops, they said 0 with vac. plugged...

[JasonHutter]

You never know with the abuse we desert junkies put on our vehicles. We just rebuilt the carb on our race truck after about 3-4 years and that was too long. It was a noticable difference after the rebuild in power. We also found a lot of dirt in all the little ports and nooks and crannies.

Jason

[JasonHutter]

My manual says the same thing. All of the trucks I have had with the 22r says 8 deg BTDC including my 22re I drive every day. We run our race engine a lot more advanced than that, as long as it doesn't ping you are usually alright advancing it some.

Jason

[gary]

with or without the vac lines ?

[JasonHutter]

The hood always said with the vacuum lines plugged 8 deg.

[BlueCoyote]

Gary,
Timing should be 6 to 8 degrees with the vac advance removed and plugged.
Doubt it is a fuel pump or filter. You would notice a problem with no high rpm power if it were a lack of fuel.
You say no fuel visible in the glass window - your float level is too low. Need pull the top of the carb and adjust the float. Rule of thumb is the float top should be parallel to the top of the cover. This will cause a hestitaion problem. Toyota carb float level is very important to correct operation.

[partybarge_pilot]

Bail the vacum advance and run strait mechanical. Total advance shoud be about 22 DEG. Toy distributors are horrible in this respect. This is the mod LC does to there "PRO" distributors. Trust me, you wont be sorry.

[gunny]

this might be out in left field but how old is your cat converter
those things get clogged up and most times they will cause hesitation flow is good under normal but when you push alot of exhaust their way at boggs down

[Travisfab]

I just got my carbed 22R smogged, and here is what I learned. Timing has to be set at 0 degrees @900rpm, I failed because mine was advanced 5 degrees. I put mine back to 0 and it passed. My truck also had the hesitation like you are talking about but I just went for it. Believe or not I also failed because I needed a new gas cap, crazy? Just go to one that lets you re-test free.

[gary]

holy crap!!!

it passed, just like it is, this morning...time to put the cell back in it http://www.race-dezert.com/vb3/attachments/old/images/graemlins/smile.gif

and get it running better now...

lc shows 2 different distibutors, one with and one without vacuum. says vacuum is better for street use...worth the trouble?

i've never disassembled the carb before, even a little bit....any tips?

timing is interesting. i called a toyota dealer, and asked a tech guy there..he said 0 with vac. off/plugged...

[partybarge_pilot]

Yes they are worht the trouble. It made a night and day differance in My old yoty. Go with the full mechanical one. Run 10 deg's initial and 32 total advance. This was the best mod I ever did to My truck. It's not that hard to do yourself. I have done several for people.

[BurnIndustires]

I agree that it may be time for carb work.. unfortunately. Sounds like either carb or ignition, your problem could just be ditributer related.. not just cap and rotor.. or maybe it just runs like a toyota with a 22R in it. Drive it til it will not drive anymore, then worry about it... Isn't that what Toyota's are good at?