Jump to content
66-96 Ford Broncos - Early & Full Size
rcunningham711@gmail.com

High idle and white smoke after head removal and install

Recommended Posts

Hi everyone and thank you in advance. I’ll start by telling you that there was nothing wrong with the heads as far as a blown head gasket. I broke a spark plug off and then an eze-out off so that left me no choice. Pulled it all apart sent the heads out and had them checked and new seals installed. Reassembled everything but did not mark distributor. Found TDC got it to start but it is running at 3500 RPM’S and white smoke was coming out. Ran it for a minute or so then cut it off. Next day started it again and had no smoke but still had the idle issue. Thinking the smoke was from coolant that got in the exhaust pipes. Messed with the timing moving it one tooth to each side but wouldn’t start. Moved back to original position and 180 around.

 

At this point back to original position that runs at 3500RPM. I’ve triple checked plugs for everything and vacuum lines. I’m I off track? Could it be a vacuum leak, pvc valve or still a timing issue.

Share this post


Link to post
Share on other sites

Yo R,

Welcome!

Vacuum leak us a usual perpetrator; 

See  my vacuum leak test in post #20 @ 

http://broncozone.com/topic/23994-90-58l-getting-continuous-code-33-and-running-code-44/?p=125535

 

One way to do a quick check is to grab a vacuum gauge. Bring the engine to normal operating temperature. Connect gauge to the intake manifold tee. BEWARE OF FAN, BELT, PULLEYS & HIT ENGINE. 
The vacuum gauge should read between 15 and 22 in-Hg depending upon the engine condition and the altitude at which the test is performed. SUBTRACT ONE INCH FROM THE SPECIFIED READING FOR EVERY 1,000 FEET OF ELEVATION ABOVE SEA LEVEL.
The reading should be quite steady. .

When engine is rapidly accelerated (dotted needle), needle will drop to a low (not to zero) reading. When throttle is suddenly released, the needle will snap back up to a higher than normal figure.

When vacuum leaks are indicated, search out and correct the condition. Excess air leaking into the system will upset the fuel mixture and cause conditions such as rough idle, missing on acceleration, or burned valves. If the leak exists in an accessory unit, such as the power brake, the unit will not function correctly. Or Air Conditioning when in MAX mode may switch to Defrost.

 

Timing, see if these are steps you took to determine TDC and time it:

http://www.fuelinjectedford.com/page71.html by Ryan M.

 

WILL ADD MORE LATER.  THIS SITE IS KILLING ME WITH ADs. Had to re type this 3 times because screen refreshed.

Share this post


Link to post
Share on other sites

Yo,

Ok, then inspect the lines cited in leak test.  Pull suspect hoses off, cap one end with a golf tee, etc. And draw a vacuum with your lungs.

 

Is it equipped with cruise control?  If so, ensure the chain to the throttle body linkage isn't causing that high idle.

 

1990-bronco-315-speed-control.jpg

1990-bronco-314-speed-control.jpg

 

1990-bronco-312-speed-control.jpg

Share this post


Link to post
Share on other sites

Checked all the vacuum lines and everything seems to be ok. Pcv valve is working too. When I ran it for about a minute the exhaust manifolds got cherry red. Could it possibly be an o2 sensor. With the white smoke at the initial start up I wonder if I got coolant in the exhaust pipes when I pulled the heads. Is that a possibility?

Share this post


Link to post
Share on other sites

Yo,

The exhaust manifold does get very hot but if it is glowing cherry red it could be a restriction in the exhaust/ restricted catalytic converter, it could be a lean air fuel mixture, or retarded ignition timing all of the above should cause a loss of power or fuel economy.

 

for plugged exhausrexhaust,  see http://www.walkerexhaust.com/support/inspections

Share this post


Link to post
Share on other sites

Alright so I decided it must be the lower intake manifold due to rpm’s. Sure enough the front gasket moved. Cleaned it all off reinstalled everything. Better idle is 3100 instead of almost 4000. Where do I need to start now? Timing? I checked vacuum prior. Any ideas

Share this post


Link to post
Share on other sites

IAC valve and throttle Body adjustment screw, also check TPS. Sounds to me like the butterflys are cracked open. Check throttle linkage.

Share this post


Link to post
Share on other sites

Yo,

Buy or borrow a vacuum gauge. The vacuum gauge should read between 15 and 22 in-HG

 

Try unplugging the IAC. If the idle drops, its usually due to an input signal to the computer which results in the EEC raising the idle speed. If this is the case, look at all of the EEC inputs to make sure everything is up to par. If the engine RPM does not drop when the IAC is disconnected, then either the IAC is not functioning properly, or, there is a vacuum leak in the engine. Stop the engine, remove the IAC  and block off the passages. Re-start the engine to see if there is any change in engine RPM. An idle speed higher than base idle specs indicates a vacuum leak. If the engine RPM is at base idle specs, then the IAC  is bad. Resistance specs are 7-13 ohms. A good resistance reading does not necessarily mean that the IAC is good. Occasionally, an IAC will become weak, and will actually bypass too much air, causing a high idle condition even though everything else is operating properly.

 

 

As Skitter advised;

Throttle Position Sensor (TPS) Overview & Testing by Seattle FSB

How to Clean and Test your IAC by Seattle FSB 

 

Has the throttle Body  screw been "adjusted"?

 

Rotate the throttle lever and allow it to return. It should not stick or bind. It should return to the closed plate (idle) position freely when released.

Share this post


Link to post
Share on other sites
Guest
You are commenting as a guest. If you have an account, please sign in.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×