Engine swap complete and ended up putting in a new OEM downpipe as well since I cracked mine while pulling out the engine.

After all this, I have a bad misfire. Engine starts but dies after about 30 seconds but if i give it a bit of gas it stays on but still will die. No CEL so gotta figure out if one of the sensors or connections are loose, doesn't sound like vacuum issue but I'll check PCV as well.

Any other suggestions?

 

Ok guys, I need some help. The car will start, it just won't stay running for long and if I go for a drive the car has like very little power. If i give it gas it will stay running but leave it idle for too long and she just quits.

I pulled the plugs, they were shot (junkyard motor) and 2 covered in oil. I pulled the valve cover, swapped the plug gaskets and put in new plugs (NGK). Also checked compression...3 were at 180 and one was at 210 so that all looks good.

I have no CEL at all...i did swap one coil pack but no difference. I am leaning toward clogged cat...i disconnected the downpipe at the bottom of the exhaust manifold but same result. I even pulled the air filter (dirty) but still same result

When I did replace the dp, i had to pull the 2nd cat....no rattling at all so i don't think that one is clogged. how do i figure out if the 1st one is clogged or what else should i try?

 

Just swapped coils and wires as well...do I need to worry about EGR or IAC?

after putting in the new coils and wires (working set from previous motor) it did sound better but then just like before, idle kept dropping and it just quit....I was able to start right away again but no better.

Why won't it stay start and why the loss of power?

 

and the answer is....clogged cat

I went for a quick test drive, came back and I look under the car to check the 2nd cat and i see the dp and exhaust manifold glowing red.

That's also why my radiator blew in the first place....now time to find me a header!

 

So everyone, I am bit stuck. I swapped out the stock exhaust manifold and installed an ebay header go for another test drive. Car still drives the same with like no power. I have the pedal all the way down but not able to get really above 30-40 mph.

When I got back, I see the 2nd cat glowing red now so I pulled that out and gutted it and still nothing different. My CEL didn't go off but I did manage to pull a code....P0132. When I pulled the O2 sensor from the header it was all black so is this just a matter of a bad O2 sensor or what else do I need to check?

 

Well considering that code is for high voltage at the 02 sensor I would say its toast. I would also check your wiring harness for any damage like frayed/melted wires etc.

 

Ok, so I swapped out the O2 sensor and now that code has come back. I am not getting any other code or CEL.

I did pull the plugs and you can see from the pic, cylinder #2 looks like new while the other 3 have some carbon build up on them. Anything else you can guys can gather from this? The gaps are fine...all 4 plugs are at 0.041

I swapped a coil out but still no better, so I am leaning toward injectors. I will try out my old 4 injectors from the original motor.

Also, the power loss is most from a dead stop and up hill...once I get going, the car does accelerate but it is severe power loss and very slow acceleration.

However the tranny seems to be shifting fine so I am quite certain its just a really bad misfire. The cats are no longer glowing red so I am getting closer.

Question, my old coil packs are quite old...one is original (230K) and the other much newer, had to replace it due to a stripped bolt. The ones from the junkyard engine have like 70K miles. Should I just buy 2 new coils? My wires are the aftermarket magnecor wires.

Will a misfire always trigger a CEL? like injector or coil?

 

A misfire will set a CEL after it has done it so many times. All it will say is misfire on cylinder ... or multiple cylinder misfire. It will not tell you why just that it is misfiring.

 

I went for a longer test drive today and finally through a code...P0300...random/multiple misfires...it seems like a lot of things can cause this

I do have 2 new coils on order but at this point I don't think its an injector problem (I swapped in 4 injectors from my previous engine) or wire issue but I am having severe misfire as my power loss causes the car to shudder at low rpm and then as the rpms increase, it just accelerates very slowly.

My gears are shifting very slowly but until I fix this misfire I don't want to divert my attention as this is the major problem

 

So this is a recently transferred engine yes? Did you check the timing/ sensors prior to installation? If the timing was off by a tooth I could definitely see that causing this issue. I am leaning away from a cam or crank sensor though because you would likely see a code for that along with the misfire code. I would check the timing belt and do a compression test on this motor as well. If they are low across the board that could also indicate timing being off.

 

I did check compression. 3 cylinders at 180ish and one at like 200...cylinder 4 was the highest one

I was thinking the same, to inspect timing as well but didn't do it before install...just wanted to get it running and do maintenance later

 

Ok....did my timing belt. I thought it would be it as the original one seemed loose but the timing mark wasn't off. I put my new belt in, off by a tooth, adjust the cam and then spun it a few times and everything lined up.

Car started up but still...it idles fine but you can hear it missing. I can give it gas and the revs go up but the acceleration is mad slow...gears seem to be better but its hard to say with such bad acceleration.

I know front and rear roll mounts are shot, would that cause an acceleration issue?

Also since I have gutted my cat, does the loss of back pressure have anything to do with this? I do have a low rpm shudder around 1500-2000rpm

I did hook up my code reader but no pending codes so I guess the misfires are better than before but still drivability is crap

I am literally out of ideas....no one rents a timing light by my house as I was thinking to check that to be sure

Any ideas...any one?

 

Timing light is for a distributor which you my friend do not have . So compression is good. timing is good, fuel is good new coils and plugs with proper gap. Something just isnt adding up here. The back pressure loss would not cause this dramatic of a mis. Only thing I can think of is ecu is toast. Or you have a bad wiring harness causing intermittent or no signals to something.

 

I would think you would at least have a pending code for the misfires. I can get a random/misfire code every once in awhile and I dont even notice any misfires

 

So yeah, I forgot to mention one thing...when I was turning the crank to line up my marks and to ensure that everything was lined up....I noticed it was really hard to turn the crank.

Yeah I know that you will get some resistance as the pistons go up and down along with the valves opening and closing but it was honestly difficult to rotate...does that mean anything?

I don't know why but I think I need to pull the engine and remove the TC and actually fully install that again or look for potential damage. I never fully took it out in the first place...I sort of dragged it out but when I figured out how to disconnect the flywheel, I never pulled the TC out....just spun it and heard one loud clunk...figured that meant it engaged and didn't think about it again. I never fully remove the TC in the first place....just to be clear...as I was taking the engine out, I saw the TC coming with and I was like there is no way I am going to clear this...lowered the engine back, disconnect the TC and then pulled out engine.

My first gear shift happens quite high....like around 5K rpm...but I am going to go on another test drive again and see if I can isolate the engine shudder and sluggish acceleration, one way or another