90f150beast

I'm having engine problems with my 90 f150 302 5.0 I bought it two months ago and it had a high idle problem like 2500 rpm high so found leak and found intake manifold gaskets bad so I replaced them plenum and upper intake gaskets, new orings on injectors and replaced valve cover gaskets put it all back together and marked timing on distributor new plugs and vacuum lines it wont stay idling it runs rough and blows black smoke any suggestions

Chris_1

iTrader: (1)

Black smoke usually means too much fuel (blue is oil and white is coolant).
Doesn't solve the problem, but that's the first direction to be looking.

wde3477

Consider -
1) Disconnecting the battery for 10-15 minutes to force the computer to reset.
2) Verify the timing, be sure the SPOUT connector is pulled for this.
3) Forget which year the switch was made from MAP to MAF - if MAP, be sure the vacuum line for the MAP sensor is connected and the vacuum line is intact (no leaks).
4) Be sure your reconnected firing order is right for your engine - IIRC, there are two different orders for the 5.0 depending on model year. Also be sure the #1 wire is on the correct post - many caps have a big ol '1' there - an error here should be picked up by your timing check too.


Hope this helps...

Chris_1

iTrader: (1)

It kind of sounds like you're getting too much fuel. Check the fuel pressure regulator vacuum line for leakage of fuel into the intake. Check the TPS signal wire for proper voltage. And since you changed all the injector o-rings, is there a possibility that you might have messed something up there ? Just a possibility.