Jcaldwell3607

I recently jerked my 305 from my 88 iroc and and dropped a 89 350 from a silver ado into the car I cleaned up the engine put shorty headers 2 1/2 inch exhaust with A flow master muffler I used accel shorty plugs but my problem now it when the car gets up to temperature which is usually around 210 it's start cutting out and missing popping and snapping I rePlaced the fuel Pump fuel filter blew the gas lines out change the Spark plugs wires distributed distributed cap rotor button change the oil is the problem electrical maybe Brian box? HelP Please

hdis2002

iTrader: (1)

Did you change the ECM when your changed the engine? Or have a new chip burned for a 350?

ninetyone

iTrader: (2)

So you went from 305 TPI to 350 TPI right? you will need 350 knock sensor, 350 injectors and 350 prom (chip).

Jcaldwell3607

I put the 350 injectors in and knock sensor but not a ECM is there another year or vehicle I can just pull one out of that will fit?

Jcaldwell3607

And I went from 305 tbi to 350 tbi

ninetyone

iTrader: (2)

You may need to get your prom re-burned then. If you had tpi then ,yes you could have used a camaro 350 prom.

rgarcia63

Being that they're both TBI, most likely the TPS & IAC need to be reset. Currently the 305 ECM has the baselines for the 305. Generally the sensors should be same with respect to sensor range. If the 350 truck motor doesn't have a roller cam you'll also need the 350 ESC module & Knock sensor. Hydraulic Tappet cams need wear additives in the oil, or oil with the proper additives. The ECM definitely needs to relearn the TPS & IAC sensor reference signals. You need to get a 350 MEMCAL pack for the ECM, or as said reprogram the one you have which would be more work than replacing it. I believe TBIs use 0° initial timing, but check to be sure, whatever the ECM thinks it is that is what you need to set it to.

Jcaldwell3607

Ok well I have heard that snagging. One out of a caprice would usually work is this right?

rgarcia63

If it's a 350 should work. Correct me if I'm wrong, but I believe the Camaro is considered a sports model, I don't the Caprice is in the same category unless it was used as a police car I don't think the programming is the same.
You haven't said if the 350 is a roller, or flat tappet cam.

Jcaldwell3607

I am not sure what it is u never tore the engine down cause I bought from a machine shop that rebuilt it to all original and the guy never had a chance to put it back in the 1988 Chevy 1500 before he sold the body and I bought it dropped it in a weekend cause it was my daily driver then one day I was driving home from work 10 mins from home and it started spit and sputtering then that's when I changed everything out but when it gets warmed up around 200 degrees it starts it does it again I never changed the ECM but I have changed the the injectors and knock sensor so I did the ECM burn out or what? And what can I do about a new one if so?

gmstrong

More then likely its a flat tappet cam some came with the roller previsions though.

justcallmeclassy

iTrader: (1)

Your best bet would be to tune for yourself, but yes this will hold you over if it is an L05 Caprice

justcallmeclassy

iTrader: (1)

And if you also didn't change your injectors there's a problem too.

ninetyone

iTrader: (2)

You know when an ignition module goes bad, they act up after the engine gets to temperature. Check into that to.

Jcaldwell3607

Everything in the ignition is new and double checked it's just acts up when it get up to tempurater

rgarcia63

"dropped it in a weekend cause it was my daily driver then one day I was driving home from work 10 mins from home and it started spit and sputtering then that's when I changed everything out"

How long after you dropped it in did it start to spit & sputter?
Everything new and double checked? How about correct parts? New parts doesn't mean good parts check your new injector resistance both cold and when it starts to S & S.
No CEL light?

Jcaldwell3607

It was prolly three or four months after I changed the engine and that when I thought was the fuel pump so started changing part after part and I went this morning and drive it it spit for a min then quit and now it seems to be idling really high between 1500 and 2000

Jcaldwell3607

And what do you mean by injector resistance?

rgarcia63

The injectors coils resistance is 16 ohms ±0.5 (don't quote on the tolerance.) The resistance controls the current needed to open the injector valve. Too much resistance will burn it out over time,or blow the fuse, too low and the valve won't open, or stay open for the length of the ECM injector pulse.

Jcaldwell3607

Well no blown fuses just idling real high I found a box on the fire wall that had a three prog plug and a vacuum hose to it the plug was damaged what is the box and would it have anything to do with this?

rgarcia63

Must likely emissions control, Google for the emissions diagram for your model. There should be one on the underside of the hood.

Jcaldwell3607

Well just found a bad plug wire but changed them an still acting up a little bit

rgarcia63

Read up on plug "wires", there are in fact not made from solid, or stranded cooper wire anymore and they don't take kindly to pulling, and twisting, which causes an increase in resistance.

Jcaldwell3607

Well now the car is idling super high maybe around two grand at most times what could be causing that?