matthewpims

Ok, well this is a rather odd problem that its seemed to of had sense I bought the car. Its an 84 se, stock except for a straight pipe, wired open aux ports, and an electric fan. The car idles like crap which I think is a vacuum leak I havent gotten to yet. However above 6k rpm the car almost falls on its face, every now and then. When it does lack power, the pull fades at 6k, power comes back at 6500 and then is gone around red. It almost seems like ign break up, It has new plugs and wires in it and sometimes it pulls well twords 8k but then other times its a complete dog through the entire powerband im about to give up, the odom has 216k miles on it, and im not for sure that it doesnt have the origional engine, so if it is the factory engine it doesnt owe me anything, im just curious to hear what you guyz think. also! is there any kind of cold start idle up for the 13b 6port??? in the morning I have to keep my foot there for a few mins to keep it goin till the engine warms up a hair then it idles ok.

BigJim

Fix your vac leaks first, also check your Throttle Positioning Sensor(TPS) That probably isnt your problem, but adjusting that then your idle and that again will help a ton.

LongDuck

The SE's automatically adjust for cold start conditions using one of several mechanisms - some effective and some not. The basic system is the 'thermowax pellet' which is located on the left (rear) side of your throttle body and when the engine coolant is cold, this termowax pellet is hard and presents resistance against the secondary throttle butterfly valves, keeping them closed. With the secondaries closed and unable to open, this restricts airflow thereby resulting in a rich mixture to the chambers.

The other cold start system is the 'subzero start assist' which actually squirts an 90/10 mix of antifreeze to water through the separate reservoir into the intake path via a temperature registering switch. This results in a continuous flow of antifreeze to the engine chambers during startup to increase compression and hopefully get the car running in the first place. This is only operational at extremely cold temps, however, and is likely not a factor in your case.

For the standard 'cold' startup, you should press the accelerator pedal to the floor ONCE, release it, then turn the key to start until it starts up - this procedure sets the primary and secondary butterfly valves in the throttlebody to the correct position which allows for a richer mixture to warm up the engine faster and also to increase compression during cold engine states.

The problem that you described about loss of power at specific RPM ranges could be due to fuel injectors not flowing smoothly (or clogged), fuel pressure fluctuations (due to vacuum leak at fuel pressure regulator on the fuel rail), bad injector harnesses (essentially 'cutting out' injector electrical pulse when the engine torques on it's mounts), spark cross-talk between plug wires or coil wires, or any number of vacuum leaks under the hood.

With an engine with that many miles, I don't think I'd be revving it up past redline very often at all if you want it to last, particularly if it's cold out where you live. But, hey, that's me...

matthewpims

Interesting, didnt know about the antifreeze thing or the wax pellet, hmm oh and im sure my tps is a little outta wack, I cant get it adjusted correctly, the best I can get it is around 1.75ohm reading on the 20k scale of my dvom, any lower and the car doesnt idle, it starts hitting fuel cut. I dont have the two little lights and when I try to use two volt meters I always get either 12v's on one and .02 on the other or 5v's on one or .02 on the other and the car runs like ***

LongDuck

Take the time and build the test light fixture. Once you have it, you will find that you can use it quite frequently just to check that it hasn't changed. Anything you do to affect throttle position (i.e., butterfly valve position) will require you to reset, so just bite the bullet.

Once you have it built, install the fixture; if both lights are on, turn the TPS adjusting screw until both lights go out, and then find the position between when both lights are out and ONLY one light is on.

Simple as that. If you insist on using the ohmmeters, disregard the values you're getting. Light on equates to 12v or close thereabouts. Set the TPS halfway between both meters getting 12v and ONLY one meter getting 12v. Follow? Good luck,

matthewpims

Yea I get ya, I guess I will just have to rig up one of those light things, thx

bizarro

iTrader: (1)

haha...i learn something new with longduck everytime he posts...yeah longduck you are a little long winded but man do i learn! i had no clue about that pellet thing...keep it coming!

but yeah i had issues yesterday with my tps...when i rev it up between 1000 and 1500 it would miss...updownupdownupdown...wierd...so i decided (from one of longducks pasts posts) to finally rig up the test light with 2 turn signal bulbs i had laying around and some wire...hooked it up as per the instructions in the haynes manual...turn the screw LOTS till i got just one light on and done...no misses, idle is perfect 800 and i feel much better about it

Thanx longduck!

GavinJuice

Well **** thats going to fix my problem exactly. I am having the same problem bizarro. This forumn is GOD.

Rotofire

the test light thing works on all first gens?