rough idle with new engine 2000 spi

[dc2000/2001spi]

Hello everyone,I've posted on other forums before but not for some time now.Probably because my car had been free of any big problems,until last week.Timing belt slipped and trashed engine at 162000 miles(2.0 spi)not bad on the mileage though.I had a salvaged spi motor from a 2001 with 80000 miles on it(almost new to me)put in it and it runs great but sometimes when it warms up the idle stumbles and drops down a good bit.I'm assuming it's a vacuum leak because i've dealt with something similiar on the previous engine that turned out to be the pcv down tube rubber elbows deteriorating.Any good ways to check for leaks?Isn't there something I can spray on the lines to find the possible leak?Also the coil pack(my original from previous engine)has some nice visible cracks in it on the two rectangular parts that stick up,would that have anything to do with my problem?I'm going to replace the coil pack with an aftermarket upgrade just don't know which on yet(screamin demon seems popular)Grateful for any tips you might have,thanks.Dave C.

[dc2000/2001spi]

another part to my first question,if my coil pack is going bad could it be giving me a weak enough spark that it would'nt be burning all the fuel and causing the plugs to foul up at low speeds and idle?

[dc2000/2001spi]

exaust gas in the antifreeze,turned out to be the head gasket

[wmach]

dc2000/2001spi,
Thank you for your posting.
Do you still the have rough idle problem in your Focus?
I have a 2000 Focus Zetec engine with similar symptoms as you indicated. Although I was not able to determine if there is vacuum leak I have replaced the PVC valve and elbow (reported in other threads as a common problem) and did not fix the problem. I have also disconnected the EGR valve output so the DPFE is disabled (as reported in Focus Hacks Focus Hacks: Ford Focus Style, Maintenance and Performance Instructions ) and did not work either. So, I'm thinking I might have a similar problem as you reported since there is a burnt oil smell after driving for a while.

[efnutton]

My daughter's car a 1999 Ford Focus had a rough idle problem also. I disconnected the EGR valve output so the DPFE is disabled (as reported in Focus Hacks Focus Hacks: Ford Focus Style, Maintenance and Performance Instructions ). and it did not fix the problem.
I replaced the plug wires ( one the wires did not to fit on the spark plug very well )
This fix the problem.

[BroncoJoe19]

When one has a rough idle, there are a few things one should consider before going any further.
Look for vacuum leaks,
check and clean the IAC
pull diagnostic trouble codes.

1. check and clean the Idle Air Control valve IAC
Ford Fuel Injection » Idle Air Bypass (IAB)

2. to rule out any vacuum leaks


Checking for vacuum leaks.
Some of the sensors and some of the actuators either read the amount of vacuum, or use vacuum to move controls, therefore it is important to the proper functioning of the engine that your vacuum system is fully intact. Otherwise one may get codes falsely indicating that there is a problem with a controller/actuator, or a sensor when in reality it is caused by a lack of vacuum.

Look at your rubber vacuum hoses (they are about 1/4 - 3/8 inches in diameter, if they are dry rotted or cracked, replace them. IF they slip on/off of their connectors too easily, they may have stretched out a little bit, cut the ends off, and put them back on.

You may listen for a leak. Sometimes using a cut off piece of garden hose is a good aid to listen with. Sometimes a cardboard tube (like from gift wrapping paper) is helpful. Just remember that whenever you stick your head inside a running engine compartment, that you are not wearing any loose clothing or jewelry that can get caught.

Another suggestion is to use a spray can of carb cleaner and spray around the bottom of the intake manifold, and the base of the throttle body assembly. IF there is a leak, you should hear a change in your engine.
Keep a fire extinguisher handy, or use water instead of carb cleaner (it works, but not as well.) Be aware that if you use water and the wires get wet and it runs worse... your wires may be bad, and the water is allowing them to arc instead of jump the gap of the spark plug.

Another suggestion is: to take a propane torch, turn it on (but don't light it) and move it over the vacuum hoses and connections. The engine RPM's will increase if there is a leak and the propane gets sucked in.

Courtesy of TheOldWizard... Don't forget to remind folks to check the PCV valve, hose and grommet !