I just finished rebuilding my redtop with new pistons, rods, etc.. I took it for a drive around the block yesterday and it was bogging and very close to stalling. I started it today and there was blue smoke coming out of the exhaust and from the exhaust side of the engine I assume do to an exhaust leak. I put some gas in it and some fuel cleaner and the smoking stopped and the idle was normal. I was unable to drive it then so I don't know if it was still bogging. Later in the day I started it up again and the smoking and bad idle returned. I checked the injector, coils, plugs, and maf and they were all fine. Im thinking that it might be bad gas since the car was sitting for about a year while I did the rebuild. Would a bad fpr cause this? The reason I did the rebuild is because one of the hoses came off of the fuel pressure regulator and I was running too lean. I also cleaned out the IACV.

Old gas is never a good idea... Drain your tank, and add 91 or 93 octane fuel. (depends on location)

was everything running good when you pulled the motor out to rebuild it, alot of times bogging and burning oil are part of the break in procedure. just got ot get them rings to seat. how old is this fuel, they say when you park a car for a while you want at least a 1/4 tank of fuel

yeah i doubt its your gas, just the rings. what are the engine specs and who rebuilt it, ring gap set correct and clocked correctly?

idahotuner wrote:was everything running good when you pulled the motor out to rebuild it, alot of times bogging and burning oil are part of the break in procedure. just got ot get them rings to seat. how old is this fuel, they say when you park a car for a while you want at least a 1/4 tank of fuel

I had a quarter tank of gas but it say for about a year. I did put some 91 octane gas in before starting so I now have about a half a tank. I know the burning oil was expected but I just thought it was weird that it would burn oil on my 1st start up and run ruff, 2 hours later upon start up run decent, and then the next day go back to running ruff. I am going to start it up tomorrow and run it for awhile and see whats goimg on again.

yeah i have had my car sit a couple times for a year if not more with that much fuel and no problems. hmmm

1 start up rough - normal
2nd start up decent
3rd rough

so what i am thinking it was warm the 2nd time you started it. so thats why it ran smooth. check for boost/vac leaks though, those along with rings not seated could make bogging worse.

do a boost/ vac leak test

start it up,
let it idle tell warm,
double check your spark time

check your grounds
double wires.

i was retarded when i started my motor up after my rebuild i didnt tighten one of the spark plugs down so it wasnt gettinn a good connection on the spark plug it was drive able. so went through and pull each coil pack out one by one and listened for a change, tell i got to the one that the didnt change the engine sound. figured it was the spark plug gap, bought new plugs waited for them to come then when they came in went to pull the old plugs and wala found the one wasnt tighend down.

so it could be something simple, just double check yourself.

also a old mechanic trick if its getting fuel and spark good for sure is to put a tea spoon of oil in each spark plug hole let it sit fora few mins put the spark plugs in and then fire it up. it will burn the oil that is inside it,but it will help get oil to the rings to seal them from the top, see how that affects how it runs

I fixed a small part of the problem. I cleaned the maf and sprayed some carb cleaner on the plugs which were fouled out. Doing this caused it to run better, and not to smoke anymore. Still not sure why it is running so rich to cause the plugs to foul out, old gas again maybe? Over the weekend I am going to install a boost gauge to see if I am getting boost and dbl check the timing again. Would a bad fuel pressure regulator cause this? I never replaced it after the problem I had with it running lean before my rebuild.

a bad fpr would cause it to run lean because the spring inside it would be wore out so it wouldnt keep pressure up. you might check to see if your injector orings are leaking. i still dont think old gas will cause it to run rich. i would try to narrow it down before you throw parts at it, sometimes that can complicate the hell out of a easy fix. deff check spark timing.

what is the car idling at? 800-900? how is it idling, are you getting back fires when you shift? what kinda of bov set up do you have

idahotuner wrote: what is the car idling at? 800-900? how is it idling, are you getting back fires when you shift? what kinda of bov set up do you have

Sorry for the delay, the idle isn't too bad. It is around the 800 to 900 area. I am using a greddy bov but it is just vented to the atmosphere. I took off the valve cover and found that I threw a rocker..again. I've been trying to find the tool used to see what size shim I need but have been haven't found anything so far. By the time I get it running I will only get to drive it from the garage that it is parked in now to the garage where I am parking it for the winter. I do have a new fpr on the way so hopefully I can find the tool I need and get a little fun out of it before I park it for winter.

the tool for measuring them is spendy, it sucks, i made my own,

So I am still having the same problem after I replaced the rocker that was thrown. I did unplug the maf while it was running and the engine did not change at all. Does that mean that the maf would be the problem? I am going to check the wiring on the maf and the o2 sensor over the next couple of days.

When you installed the springs did you check spring load and bind? Or did you just replace the springs? Its possible that the springs are not shimmed properly.

I used a tool to measure the shims so I believe those are correct, plus I haven't thrown any rockers since installing them. The springs should be fine, I didn't have to replace or uninstall the springs when I did my rebuild. I am going to order a new wiring harness since the one I have could be better. Im still trying to figure out if the maf could be the problem since when I unplugged it while the engine was running it made no difference.