NEED HELP!!!

[FEARNONE30]

I have a 91 sho and it runs like crap. It is flat from idle-up. Hardly any power. I put new wires(motorcraft), plugs(agsp32pp), valve cover gaskets and plug seals and cleaned the IAB valve. Compression and fuel pressure are fine as is the timing. There are no stored codes either. It starts fine and idles but sounds even flat idling. The converters are o.k. also. I am asking for you guys to help because I am running out of patience with this thing. Any help or ideas would be appreciated. Thanks.

 

[jelloslug]

Check to see if you secondaries are working properly. If they are stuck open the low end will be very flat. Have a helper watch the vacuume actuators to see if they close when you start the car, you should be able to see the rod move. If thats your problem check the vacumme lines and the actuator that located on the backof the intake. Whan I got my '90 the electrical connection to the actuator was unhooked.

 

[sdpatt]

How about some history on the car. Did you just get it? Has it always been down on power? Any unusual noises? Other things that you have checked?

This could be caused by a wide variety of problems such as greatly restricted exhaust, a mistimed timing belt or the SPOUT (spark output) plug being removed. Help us narrow down the source with a little more information if at all possible. We want to help.

 

[FEARNONE30]

I just bought the car 2 weeks ago as is. Good deal. Besides all of the above, it has good oil pressure and the motor is quiet. The valve lash on all valves were all in spec. Other than that, I didn't know where to go. It has 103,331 miles on it and I have a new water pump(doesn't need one) and timing belt on the way. I drove this car 80 miles home and besides it running flat, it ran flawlessly. Driving it home was probably not a good idea but I don't own a trailer. Thanks.

 

[FEARNONE30]

Sorry, I forgot one thing. Does anyone have pics of the secondaries actuator and where it is located? Thanks.

 

[jelloslug]

There are 2 of them; one on the front tank (the part of the intake that says "SHO 24 VALVE") and one on the back tank (the part with of the intake that has the Ford logo on it). They are in between 2 of the intake runners and are vacumme actuators with 1 vacumme line running from each one to a T connector that leads to the controler on the back of the intake (it a black cylindrical
unit with vacumme lines and a 2 wire electrical connection).

 

[projectSHO89]

Watch the actuators as the engine is first started. You should see them move as vacuum is created.

With no vacuum, the secondaries are open. They should close on startup, then open up again at 4K RPM. Anyone with an MTX can ovserve this by reving the engine. (Sorry, ATX guys, you can't do that)

BTW what exactly does "runs flat" or "sounds flat" mean?

Steve

 

[FEARNONE30]

Last night checked the spout connector and the vacuum and connection to secondaries. All o.k. By saying it is flat, I mean it idles fine but it sounds like a riding tractor with a fouled plug. It sounds muffled but there is no restriction in the exhaust. Does this help?

 

[LaTechSHO]

so you don't have any misfires, you just have no power??


have you run the codes from the computer to see if there are any active or STORED codes??

Louis

 

[FEARNONE30]

Like I said above, Compression, fuel, timing and connections are all o.k. NO CODES. Soon to be a 91 SHO with a new owner.

 

[JaySHOguy]

Are you sure that you installed the new plug wires in the correct order on the Coil unit?

I know that certain repair manuals have the order listed wrong...

 

[SHO&'Vette]

can I ask a stupid question that adds nothing to this discussion? No? well I'm going to anyway ... what does "HIWABFH" mean? I'm thinking it's going to be as funny as the description of your ugly car ... if it's too raunchy to write it out, just give me hint.

 

[shojuan]

SHO&'Vette:
can I ask a stupid question that adds nothing to this discussion? No? well I'm going to anyway ... what does "HIWABFH" mean? I'm thinking it's going to be as funny as the description of your ugly car ... if it's too raunchy to write it out, just give me hint.

Hit It With A Big F'in Hammer

 

[AutoSHO]

FEARNONE30:
Last night checked the spout connector and the vacuum and connection to secondaries. All o.k. By saying it is flat, I mean it idles fine but it sounds like a riding tractor with a fouled plug. It sounds muffled but there is no restriction in the exhaust. Does this help?

Your problem sounds like a skipped timing belt and/or the plug wires out of sequence. Do a search on Plug Wire Sequence and you should be able to find an illustration with the correct order. Another thing to check: Disconnect your cat-back exhaust from the Y-pipe and use a leaf blower to check for any restriction. One member here had his car lose over 100 hp just because of a plugged catback. Another member lost nearly the same because his timing belt had skipped a tooth on one bank. Good Luck!

 

[91 SHOplus]

SHO&'Vette:
can I ask a stupid question that adds nothing to this discussion? No? well I'm going to anyway ... what does "HIWABFH" mean? I'm thinking it's going to be as funny as the description of your ugly car ... if it's too raunchy to write it out, just give me hint.

Thanx T! I have been wondering that, but didn't want to ask. thumbs_u

Now that I know, I agree whole-heartedly!

 

[SHO&'Vette]

thanks, Rick, I should've known. My variation on that theme has always been "if it doesn't fit, force it"... and now I know which tool to use!

 

[jelloslug]

I always called it "percusive engineering"

 

[sdpatt]

Here are the methods to check the alignment and tension of the timing belt. To check the belt's alignment, rotate the engine crankshaft in the clockwise direction using a 19 mm socket on the crankshaft damper bolt (or other method) until the second, white notch on the inside ****** of the crankshaft damper is aligned with the "0" line on the timing tab on the lower timing belt cover. This positions the engine to top dead center (TDC) on the number one cylinder.

Now remove the ten 8mm bolts on the upper timing belt cover and remove the cover. You may have to remove the single screw holding the power steering fluid reservior to the bracket and move it out of the way to access the bolts and remove the cover. Secure the reservoir with a tie-wrap and position it so that it won't leak fluid. Note that the two bolts in the center are slightly longer than the bolts on the perimeter of the cover.

Looking at the camshaft pullies, they should be positioned as shown in the two photos below. Ignore the position of the white marks on the timing belts as they are only used to position the belt during its initial installation. You are verifying that the index dimples on the cam teeth and cam spokes are aligned with the raised ridge on the rear, metal timing belt cover at the 12 o'clock position.

If they are not aligned as shown, your timing belt was either installed incorrectly or the tension was not set properly and the belt skipped on the pulley teeth. This will require that the belt be reinstalled. I recommend that if this is the case to plan on replacing the belt with a new Gates T248 belt from RockAuto.com for $34.77 (EDIT: no longer available).

The belt should be quite firm to the touch. If you press firmly on the span between the two camshaft pulleys, the belt should deflect no more than about 1 mm. If the belt is aligned correctly but the tension is less than specified, you can retension the belt with the timing belt covers installed per the procedure here.

Search keys: timing belt alignment and tension

Front camshaft pulley index mark alignment (ignore the white mark on the belt)

Rear camshaft pulley index mark alignment (ignore the white mark on the belt)