rebuilt but will not run

90blackbird

Registered User
My 90 has been down for 6 months. rebuilt engine, all back together. When I try to start it runs extremely rough and shuts down. Checked all connections, fuel pressure, sc tube connections, doubled checked plug wires. Ripped engine back apart to check timing to make sure I didn't screw up the marks. All appears OK. I have had it at a tech school with 5 (count'em 5 master mechs) to no avail. I followed the manual when when tighting the rockers, looks to have no adjustment. I had .003 taken off the heads when they were rebuilt. Is that enough to change the push rods? Book says .09-.019inch clearance. I do not have that. More like .009-.012inch. Any ideas, I am about done!!! But despite all these issues, I like this car..........
 
Man I feel for you

I just got done doing a minor porting of the SC, new power steering pump and a raised SC top. got it all together and it runs so rough and wont idle. Im at my end of my rope and have had thoghts of getting rid of this pig. It just seems like when you mess with anything it all goes to hell. Just a thought on your car
did you mark the cam sensor position? This is one area where most go wrong. you can buy a alinement tool for that as well.
I have rebuilt 2 of these motors so far and they are a challange to say the least. Oh well back to the garage for more punishment.
Mark J.
 
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I have spent so much time on this beast. AI detailed the heck out of this thing, looks so good...Just let me drive!!!! I am in the process of putting it back together for the second time. Is there anything I am missing with the valve adjustment. Looks simple by the book. Would .003 mil require differnent push rods?
 
should require diffrent push rods, the lifter should be able to compensate for that.... besides even if it had to much play they would tick alot before it would start to run bad......

When it shuts down, is it because of NO SPARK, or because of NO FUEL, try spraying carb cleaner in the pcv valve if you have spark if it doesn't have fuel it will run off the carb cleaner.

Let me know what happens.
Tim
 
will try carb cleaneer when I get it back together. I checked fuel pressure, it was correct. Someone, can't remember who said if the sc tubes were not sealed it would run extremely rough. Is this true?
 
It looks like someone already had the vacuum leak idea, but maybe my tow cents will help too...

I had the same problem when I reinstalled my motor. I had a cracked EGR tube and thought I could do the first start without it. The motor ran like crap. Just like you described. I plugged the EGR openning on the manifold and it purred like a kitten. Check you tube. For that matter, check for any vacuum leaks because they all have the same effect.

It sounds like it only starts because the computer dumps more fuel into the engine during startup and then stalls when running with the correct mixture(actually too lean with vacuum leak).

Good Luck...
 
Thanks for all the info. I had sealed the tubes with red rtv, let dry 48 hours before starting. Don't believe I used anything under the SC top. What should you use. Also when the flanged tube mounts to the back of the SC there was no gasket. Looked like metal to metal. Should it have a gasket or some type of sealer.
 
There's your promlem. Use Lock tite 518, you can buy it from Graingers. You could also use RTV although since you have to pull the blower back off anyway I would use the 518.

Jeff
 
Check vac,egr, and cam sensor.....

That cam sensor has to be right on the money, any vac leak will screw you,and if the egr gasket is not sealed, or the tube is cracked, you'll have problems. Fortunately you can still get the tube from ford, but by all means make sure you do not have any vacuum leaks.
 
Just the top and inlet plenum. RTV on the tubes, or contact Wynn (tbird88) he's got some teflon gaskets that are reusable.

Jeff
 
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