Ok so a little info, I have an 86 iroc with a 350 in it we did the swap ourselves. We started 13 years ago ran into some major issues with the car and in my adulthood I took on the task ! After replacing engine wiring harness, computer and fuel pump, I finally got her started ! And it was all thanks to everyone here ! Ok so I'm gonna try and explain some issues I have point by point.

She started not super easy but she got there, now I have a pretty rough idle it seems as though the timing is off by quite a bit, i got it warmed up and put my foot on it and misfire !

After getting it up to operating temp I pulled the ESC plug ? For the distributor and fired her up again she ran great for a minute, then rough idle again and then out of nowhere a pretty loud knocking sound coming from I believe drivers side of the block.

So for the rough idle is my timing off ? Or vacuum leak maybe ? Also any ideas as to what this loud knocking sound was it scared me ! Considering I have no miles on this engine

 

Anybody out there ??

 

Ok so I pulled the EST and ran it and tried to advance the timing to 6 degrees but I can't get near it without the car dying ! Is it possible I'm off a tooth with the distributor ? Basically is the distributor out of place ?

 

If the distributor would be out of place, rotating it to 6*BTDC with timing light would fix that, right? Unless the timing tab is out of whack. Engine has to be fully warmed up before disconnecting the ESC. I assume you have a TPI? What ECM do you have? What was the original engine? TPS has to be adjusted, IAC has to be reset and Throttle Body screw has to be adjusted too. AT or MT?

 

Yes it would fix it I think, I can't get the timing to 6*BTDC when I rotate the distributor, it stops at about 0* and dies when i try to go further. it seems like maybe I have the spark plug wires all just out of place by 1 maybe ? This is my first time messing with timing in general, so I'm not sure what rules apply you know.

Engine was fully warmed around 220ish, yes its a TPI, it originally had a 305 in it, it's now a 350 with a beefier cam. It's an ECM from an 87 corvette with the stock chip without the VATS. Automatic transmission 700R4

I'm sorry, im not sure what TPS is, or what the IAC is anyway you can dumb it down for me on how to check these things along with the throttle body screw adjustment ?

 

Also does the timing have to be at 6* before I make these adjustments?

 

May I suggest you do some searches on TGO.
Lots of info on TPS, IAC and throttle body adjustment, etc.
Also, maybe you want to check your basics like fuel pressure and firing order.

I assume your ECM is a '7165 with $32B mask and your BIN could be ABTD or ABTF depending on which '87 AT 5.7 Corvette it came from. Were the injectors matched? Still have the CSI?
Be nice to datastream and see what's going on.

MAF don't adapt well (despite theory) to modified 350, specially at idle.



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You may want to start with the basics like make sure piston 1 is at TDC and distributor rotor is pointing to where it should point. the noise you hear sounds a bit like a rod bearing problem - hopefully its not that. Did you rebuild this motor, have the timing chain off, or remove cam or anything like that?

 

Hey sorry for the late response, I haven't had a chance to work on it, ok so it's a crate engine the only thing we replaced is the cam. Maybe this weekend I can upload a video. Also the knocking isn't all the time, I might even say it could be pre ignition ? Is that possible ? It only happens when I pull the ESC and I turn the distributor in a certain direction

 

the injectors are 22lb fuel injectors I think they are from Ford, and yes that is the model ECM, with the ABTF. What is a CSI?

 

Is it possible you got the cam in wrong position? That could cause all kinds of havoc such as you describe. You should be able to check by watching valves open/close has you turn motor by hand and make sure intake/exhaust valves are opening for the correct piston and correct time and watch distributor rotor while doing so to make sure it is also in correct spot.

 

That would suck, but once I get a chance to look at on Saturday, I'll keep you guys posted thanks for the help !

 

ok so we bought this engine from a guy who sold rebuilt gm motors, and replaced it with a beefier cam. I just started it today after replacing the spark plugs and I was able to get it to 6* and it ran well, I turned off the car to connect the ESC back up, now it won't turn over ! I know that if I retard it it'll probably start am I too advanced ? I left the distributor where it is at 6*. Is it possible with the beefier cam I need a more powerful starter ? I also replaced the starter with an OEM one a month ago. Any suggestions ? Is the marker for the timing out of place ?

 

Anybody have any tips?

 

Anybody out there ?!

 

are you sure you got the right timing cover with the correct balancer ??? also the starter you have should work fine. if anything, the beefier cam will bleed off a little more pressure and it may be a little easier to start, in theory anyways. kinda sounds too advanced if it doesn't want to crank after the engine is warm. i'd verify you all the correct parts as well. and since you got a non stock cam, you probably need to get the ecm tuned for it. hope this helps. god bless