iworkalone

Need help BAD! This just started happening out of no where. It's an 87 w/ a plow on it. When I bought it (couple of years ago) it had a high idle, no 02 sensor and was getting about 85 miles per TANK! The electrical system is pretty wacked also, about a year and a half ago I was pushing some snow & hit something pretty hard, caused the truck to die. Got it towed into the drive, 2 days of troubleshooting in sub zero weather & the only way to get the thing running was to put a jumper in the interior fuse box to get power to a circuit that had lost its power source (the same circuit operated the windows & radio). I could not find a break anywhere and since the jumper got it running I didn't care. So after that the fuel regulator was replaced, wires, plugs, cap, rotor, coolant sensor (only the green one, can't find the proper replacement for the black one next to it, the threads are always too small but it seems to working properly). Timing is spot on, mileage is up to about 125 per tank but I couldn't get the idle down. I replaced the TPS last year (which with the fuel regulator helped with the mileage). Then suddenly this past fall it started acting up. I replaced the TPS AGAIN and it made it worse. The thing starts right up, even a few weeks ago when it was almost 40 below, it purrs but I cannot get it to go more that 25mph soon after warm up. It has ZERO POWER. If it is cold I can floor it and it goes but right after it warms up (I mean RIGHT after) if I floor it rpm's won't go above around 1500, starts sputtering/ backfires. The only way I can even get to 25mph is if I barely touch the gas pedal.
Also after i start it up no check engine light but right above 2k rpm it comes on. When I check for code none show up! I can turn it off while driving dump the clutch to start and no cel, hit that 2-- 2.5k rpm and it comes right back on. i just replaced the 02sensor AGAIN no change. I can remove the connector from the tps and no change. I can disconnect the 02 sensor and no change.
I have purchased a cold start injector but have not installed it thinking that is was dumping fuel after warm up but when I disconnect the electrical connector there is no change after warm up but if I leave it disconnected while cold it won't start.
Is it possible that the coil is bad? I have checked spark on each wire and looks fine but when I operate the plow under load the truck will die (it doesn't because I just bump the switch) but if I operate the plow when not giving it gas it works fine. It is a newer alternator but I was going through belts, I thought that maybe the alternator might be defective. After the last belt change, about 2 weeks ago it has not squeeled.
I put the old TPS back on today (again no change) but the idle was much better. After sitting in the shop for about an hour after install/ adjust I started it and it had a nice low idle which caused the brake & whatever the light just above it to lightly flicker but after I pulled it out & drove it same problem then the idle went back up. As far as the idle goes I cannot get it down, even if I adjust the idle screw all the way tight stays @ 1k. Throttle cable is adjusted properly.
What would cause a check engine light to come on but no code to be stored?

Any help/ idea's would be greatly appreciated, I have been messing around with this thing for a couple of years now. Have always been a huge fan of the 22re (have an 83 celica gt runs perfect) but getting to be too much.

combatcarl

Have you ever adjusted the TPS? I see replacement, but not adjustment.
http://4crawler.com/4x4/CheapTricks/TPS/index.shtml

iworkalone

Yes I have, multiple times. Even so I will check specs again but this time at the ecu per your link. I have suspected the connector before but have not come across the schematic. Thanks for the advice

Stuwy123

iTrader: (1)

What's the intake gasket look like? The one right behind the throttle assembly. I managed to put that one on upside down and gave me a nice high idle.
A ridiculously high idle means an air leak usually or it's set high.
Does the throttle valve return properly? Does the dashpot (1" black plastic cylinder w/ piston on the throttle) work properly and only limits the return?
A bad coil or wrong spark plug wire order can limit throttle.
Any holes between the intake manifold to the air filter?

iworkalone

I will check the intake gasket hopefully later today. The dashpot seems to working fine. But what's up with the cel then no code stored? I am going to check the alternator, in my post I mention it wanting to die when I bump the plow. Also on the rare occasion that the idle is below 1k a couple of lights flicker (lower right part of the display, brake and forget what the other one is). It's just wierd because I have a near brand new powerful battery and it seems like it is getting charged, I drive around all evening with lights on and doesn't kill it. Also those 2 lights sometimes flicker on when I am driving around. Alternator belt is brand new. When I do check it I am going to throw an O- scope on it, maybe throwing some noise to the ecu?

iworkalone

So I didn't check the intake gasket, after I thought about it couldn't be that, this problem just started happening.
Yesterday I replaced the cold start injector, no change. OHMed out the AFM and all was good but the temp sensor seemed off. The spec's in the worthless haynes manual did tell me that the values didn't seem right although with the huge gaps in temps it I couldn't really tell. It was about 40F in the shop I was working in and the closest values to that temp told me that it was not reading right. Could this cause the problem? It definitely has to do with either temp or electrical. I was in the shop for a couple of hours and when I left I could hit 35mph pretty easily but it was night time and bitter cold so I had the lights on. When I bumped the plow under load as usual it wanted to die THEN the power loss was immediately noticable. But every time I check voltage on the battery it shows a steady 15v. Going to try & disconnect alternator during the daytime and see what happens.

Terrys87

iTrader: (1)

I had a vacuum leak cause similar problems. Check from AFM to Plenum and all other connections and gaskets.

Check engine light and No Codes is a sign of vacuum leak as well from my experience.