scrappy76

Quick situation. I took a worn out 2.8 out of my chevy s10 and stuck in a 3.4 from a camoro. the engines are practically the same just alot more h/p in the new motor. anyways, I used the same distributor from the 2.8 with the ignition module on the inside. I used the same coil,cap,rotor,and plugs. the 3.4 has a edelbrock manifold and a 390 holley on top. Ok here the deal. I get it to start, rev and run for a couple minutes, then it starts coughing and dies. I try to start it and it wont start and I start smelling gas, So I assume fuel is not the issue. I check for spark from the coil to the cap, and its like a bright orange. I pull a plug wire off a plug and I am not getting anything. I decide to change the cap and rotor with new ones. I try to start it and after it burns off all that extra fuel she starts and runs for a few minutes then again coughing and dying, and again I try to restart and just start smelling fuel. So at this point I check the coil and again at the time I check it, I get spark orange in color. I think maybe the holley 390 I got that was used is a pc of garbage so i pull it, and throw on a holley 600 that I was on my corvette before and know it works great. I try to start it and once I clear out all that gas, she fires up and actually runs better and longer, then she starts coughing again and dies. I can throw parts at it but I thought maybe I can get an opinion or two before I do. I do not have any meters or testers. I plan to change the plugs today.
I am thinking either a going bad coil ? ignition module ?
I am sorry for asking about something besides a vette, but you guys are pretty smart, figure you might help me on this.

MelWff

you make no mention of what year you are dealing with? does the S10 have an oil pressure sensor that will shut off fuel if no or too low pressure is sensed?

scrappy76

Well the year is a 89, but the oil pressure sensor switch is not even being used. Lets just say that every wire is still being used for the new motor that was used for the old motor. the old motor was running just worn out, weak oil pressure ready to be put to pasture. I stuck another motor in using all the same wiring, including the distrib and coil. The gas is not an issue, I can smell it when I am trying to restart it, I can see it squirting when I open the throttle with my hand. The engine will run for a few minutes then die. Then when I try to start it I smell gas.

mikem350

What happened to all the sensors, was it carb or FI?
Like MAP, IAC, TPS etc?

scrappy76

I bought the truck, the 4.3 motor was removed. the original owner threw in a 84 2.8 carbd motor in it. only hooked up what was needed to run the 2.8, ie ignition, fuel, oil pressure gauge and water temp gauge, vacuum lines, electric choke. I used the truck for about two years and the engine was just getting more worn out, whow knows how many miles on it. The oil pressure was getting weaker and weaker and going up hill was just too hard on it. So I found a 3.4 motor, installed a edelbrock intake and holley 390 carb. I took all the stuff off the 2.8 including the distributor, accessories sensors. And here I am today.

Jebbysan

If you are using the in tank pump....you need a regulator.
I bet that is your problem.....stock 89' TBI was 12-13psi.
You need 6-7.....

Jebby

Jeffs82c3

The spark should be blue colored, orange color usually means the coil is dieing...

scrappy76

Hey Jebby,

Good call, but actually the tank pump was removed when I bought the truck. The 2.8 that was in it had a block mount pump. Now on the other hand, the 3.4 I just put in it has no place for a fuel pump, so i put an inline e-pump for fuel @ 7-15 lbs.

scrappy76

Thanks Jeff. You are correct. I just ordered a new coil so i will install that today. I did however find my problem. The p/o Had mounted the coil in a way I could not see, so When I hooked up the e-pump to the coil for a key switched circuit, I hooked it to the wrong side, so the pump was drawing all the wrong juice, killing the coil thus led to it heating up,and cutting off and the engine flooded. Even the the coil needs to be replaced, she is running awesome. Thanks all for your thoughts. I didnt mean to throw something different atcha, just some old school wrenching.

Jebbysan

That is what cornfused me as 3.4's do not have fuel pump provision on the block....
Glad you got it fixed....
I have owned 14 S-10's since the 80's.....sold the last S-Blazer one month ago!
Sometimes it takes listening to ideas to track down the issue....and that is really what forums are for!
Good job.

Jebby

scrappy76

Love the s10's, this is my second one. This is also my second 3.4 swap, though the first one was a crate motor and tbi, pretty much plug and play. This one though simpler with a carb, the truck itself is a frankenstein truck that is an 1989 that had a tbi 4.3, that was ripped out when it died, then the p/o stuck a carbd 2.8 from an 84 did a bunch of hacking of the wiring. The truck itself was is awesome shape no rust at all. had to have it.
Anyways back to corvettes

bluedawg

I agree with Jeff and think the next course is with the ignition module or the coil. The spark should be blue and if your not getting spark at the plug after it dies but are at the coil. Better yet go with a v8...if I read the entire thread I'd seen you figured it out. Good deal.

scrappy76

I like that, go with a V8. Well if I didn't have to change the tranny also, I probable would have. Though, this 3.4 I just put in it, will be pushing about 200hp. I did solve the problem and I will be changing out the coil and the plugs this weekend.