1985 z28 new engine issues

hi, this is my first post on these forums =D

i have a few problems with my car that im having trouble with and i need some help, let me start off with a little history of my car

1985 z28 305 with TPI, automatic transmission - 700r4

i bought this car a year and a half ago, for $1500, had to tow, the wiring harness was in the trunk lol

we were told that the engine and transmission were rebuilt

worked on it over a period of 4 months for a lack of money, it was supposed to be a project car anyway so its ok...

i drive it for 3 months, then one day going about 70 on the highway, i brake a little cause of a cop....then when i go to re-accelerate, there is no gas, i notice the car is OFF, so pull over, tow home and see that the cylinders were so full of fuel it was under high pressure (i couldnt even turn the engine it was so high)

i removed all the spark plugs and that solves that, i found out that it was the injectors fault for filling the cylinders so i replaced them, they were 20 years old...lol

then it runs but with a hard knock and shakes the car violently, and tries all it can to die, if i hit the gas the knock goes away at a higher rpm, but there is hardly any power

over the next year i have replaced the engine with a remanufactured shortblock and new remanned heads with my TPI

i just put the engine in 6 days ago and today its running, but with a catch

in park it idles at between 1200 - 1500 rpm, with a soft knock and yes it does shake the car, but its alright, kinda

if i put it in drive, it drops down to about 800 - 900 rpm with the same violent knock and shaking of the whole car, when i put it in reverse the rpms go up for a second but then back down to what it was in drive, with the same behavior

its soooooo off and i dont know why, everything is new, distributer and cap, wires, plugs, IAC sensor, O2 sensor, so many sensors i cant remember them all, the IAC i replaced today, and good thing i did, cause it was nasty...lol

i read alot of these threads and i think im fairly certain that its a misfire somewhere, by reading these forums i see that maybe some codes can tell me what might be wrong, but im unsure about them, there is no CHECK ENGINE light on, so would that even help me?


thanks in advance

What you need is to hook a scanner to it and see what is going on.
Start with a laptop like this one http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6786466539&category=42206&rd=1
Then down load WinALDL here http://winaldl.joby.se/ and alos on that page is a link to how to build the interface cable for it (simple 1 transistor cable, costs about $2 to build)

thanks for your response, ill try that, but dont you find it odd that it would behave the same even with the new engine, i mean, the old one had bent push rods, a messed up crank, the list goes on....and it does the same as it did before i pulled it, just thought its a bit wierd

well i found the problem, even though my guage says there is perfect oil pressure, no oil is being pumped....................................yea yea i know



i just put this engine in a week ago and now i got to pull it back out

well i found the problem, even though my guage says there is perfect oil pressure, no oil is being pumped....................................yea yea i know



i just put this engine in a week ago and now i got to pull it back out
Before you pull the engine! Pull the distributor and make sure the oil pump drive rod is in there. If it is, get a pump priming tool and 1/2" electric drill. Pull one of the valve covers and use the priming tool (with the drill) to turn the pump and see if any oil comes trickleing out of the pushrods/rocker arms. If it doesn't, jack the car, support the engine with a jack on the harmonic balancer, remove the engine mount bolts.
Now VERY important! Don't put the distributor in yet! Jack the front of the engine a bit, remove the oil pan bolts and drop the pan...is the pickup screen still on the oil pump? If it is, remove the pan and look towards the back, there should be a plug for the oil galleys back there. If that plug is missing, you won't get oil to the engine parts.

well this is what happened, i looked under the valve cover on the driverside and there was no oil coming pushrods, so i assume no oil is pumped, the oil pump drive rod is there....

i am now faced with 2 problems

#1 i suspect the oil pump defective now (some history is that i bought a short block from city motor supply that happened to have an invisible crack in the first cylinder, i found it the hard way, so water was getting in the oil, with this pump, and this pump was new too)

so i think i messed it up because it was pumping a water/oil mixture and i bet there is rust all throughout it now, and thats y it wont pump, i think

#2 even if i replace the pump, the way the car sounded with that hard knock sound i bet all the bearings are now scarred, which would mean i got to re re rebuild it :sadface: