Ok guys here's a goood one. I have a 1994 850 Turbo wagon with 50,000 miles on it. Well, the kid drove it to vegas a few weeks ago and a heater hose let go and it blew the engine. So had the engine rebuilt and away we go...
Now I have a miss-fire under load (no blinking Check Engine light).
When the car is cold, the misfire is only under full throttle full load top-end power (3500+). As the engine gets warmer, it misses/surges under heavy load, the progressively lighter loads from there (and you can smell the cat getting really hot - lean? IDK).
I have no idea what spark plugs are in there (but they were part of the tune-up kid from IPD) and I am pretty sure the vacuum hoses were replaced for everything.

It wasn't like this before. It ran really good.

Any suggestions as this is a nice car with low miles and now a rebuilt engine I would like to keep for a while.

Thanks in advance for your help.

Demian

 

When they rebuilt the engine and put in new plugs, did they put in OEM plugs? Also, do you know if they were gapped correctly?

 

1. how did you blow the engine when you blew a heater hose? (rad hose?) he kept driving with it pouring smoke out of every crevase?
2. why are you beating your car when its cold..?
3. i would change the cat + check the plugs too,.

 

Bosch Plats were gapped at .022 I regapped to .028 and it runs much better.

Also the hose clamp attaching the intake hose to the MAF was missing.

I runs alot better, but it still misses/surges on the top end (when warm). No cat smell this time either.