A Little MFI Help please!

[deoxford]

I know I always asking for help, and as soon as I get my car sorted out I will be able to help everybody with the same.

Now for the question: I have a 2.4 MFI and the gas seems to stick
I found that the sticking is on the MFI not the pedels.
Has anyone had this poublem and how to you fix it?
What make the throtle return to the correct spot on the MFI?

Is there a proublem spring I should be looking for?

When I reach in the engine bay and pull on the linkage I can get the throtle back do , but It never really goes down all the way
So It idles at about 1200 , once since I start the car on Sunday has the idle be low at about 800.

I can't drive the car till I get this fixed.
Jim where are you?
Thanks For the help
Derek

[deoxford]

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[KevinG]

Derek -

I had the same problem with my 72. A temporary fix is to get a carburetor return spring from your local auto parts store and attach it to your throttle linkage somewhere. I found that this extra spring was enough to ensure that the throttle returned to the stop when the gas was let off. I got one about 14" long and attached it to the throttle linkage pivot mounted to the transmission.

I really don't know what the cause was, because the problem went away after I rebuilt my throttle bodies and MFI pump. Could have been as minor as hardened grease in the linkage cups or as major as binding throttle body shafts.

Good luck!

[deoxford]

Kevin,
Thanks for the idea, does this look correct?
I want to make sure nothing is missing

[deoxford]

Kevin,
Did you rebuild the trottle bodys or did you have someone?
Derek

[304065]

Derek,

This could be a whole bunch of things. Start at the gas pedal and work backwards.

Behind the pedal there's a metal linkage with a ball on the end. This fits into a socket on the pedal. Gently pull the ball out of the socket by pulling the pedal forward. Don't rip the pedal off the floor! You should be able to move the linkage around and see if it's binding on anything. Pull the carpet up. Use a 10mm socket and remove the pedal board. Look in there to see if some french fries or something is blocking the pedal. Clean and lubricate as needed.

Your next step is the exit of the throttle cable from the tunnel. Jack and support the car solidly in the rear. Put the rear tires under the car for safety, as illustrated in Wayne's pelican graphic. We don't need you getting crushed flat like Wile. E. Coyote, now.

Once under the car, check to see that the throttle cable is not binding at all where it exits the tunnel. If you still have the old rubber coupling, replace it with the rubber coupling with the metal sheath, this will allow you to get home. The cable goes to a bellcrank on the transmission, and from there to a metal rod that runs up into the engine compartment that actuates the throttle linkages. Verify the rod's not binding anywhere. Clean and lubricate the bellcrank, it's probably greasy as hell.

Now, with all that done, in the engine compartment, check to make sure the linkage is not bent or otherwise out of whack where it connects to the cross link. This is the metal pipe that connects both banks of MFI stacks. Clean, lubricate, etc. etc. etc.

If it's a throttle linkage problem that should take care of it. If it's a mixture problem, that's an entirely different question.

Good luck!

[Jay Auskin]

There is a spring needed. It's part number:
901 110 131 00
It will cost you ~$8.50

This spring is connected to the linkage attached to the throttle body. Check to see if it's broken...mine was. I replaced it, and it returns all the way.

#29 in the picture------>

[Flying Toaster]

My problem was the rubber boot under the car where the cable exits the tunnel. The boot was getting bound up somehow. It was not only preventing throttle return, but also wide open throttle.

I have a 2.4 w/MFI in my car as well & I agree to also check the #29 spring. -John

[Zeke]

I had one long piece of linkage that rubbed. It was the one from the engine bellcrank running past the t bodies to the one that hooks up to the pump. I had to bend it just a tad after lowering my gas pedal for heel and toe. Don't know why it rubbed then, but it did.

[Jim Richards]

My first thought was just what Jay posted. Check the spring on the crossbar.

[deoxford]

I went and disconnected the linkage and found two things,

A. something is keeping the gas pedel from moving, all the way.

B. On the MFI itself the very far cylinder on the left bank is sticking...
I WD40ed it but it really didn't seem to help... I will work on some on weds.

I will post more when I find it.

I am ordering a new spring also, the thing is 31 years old!!!
Thanks for the help
Derek

[thastings]

Derek,
Check your hand throttle to see if it slipped.

Terry Hastings

[warment]

I had the same problem. Mine was caused by the Warm up regulator. There is a little black plastic arm with a "roller" tip that was no longer a "roller" tip. The tip was worn flat and would bind up. I just removed the WUR and my problems were fixed.

Bill