Missfire Issue

[TOOLOW91]

At work thinking and would like to hear you opinions. I did the gt40 intake swap over the weekend . I used the explorer gasket set . Start the car up and it runs first shot. No vac leaks , Nothing but i have a miss fire.

Now if it was a slipped gasket or an issue I would have a huge vac leak. I re dropped the dist on tdc, I haven't pulled the upper yet maybe i missed an injector plug on the driver side? Plug wire bad ? What do you guys think ? I really don't want to pull the lower again so i am just waying my options and am bored at work.

 

[jcgafford]

you sure you stabbed the dizzy correctly? a tooth off is problems...

 

[TOOLOW91]

you sure you stabbed the dizzy correctly? a tooth off is problems...

3 times i even had my friend come and do it because i thought i was going crazy!!! i feel like a dope it has to be something so stupid

Edit- But thats the joy of DDs. I put the car away and said monday after work i will try again

 

[jcgafford]

well, what else did you move? sounds like dizzy or a vacuum leak is the only possibility

 

[TOOLOW91]

well, what else did you move? sounds like dizzy or a vacuum leak is the only possibility

Just pulled intake, Cap and wires - left the wires on the cap, Dizzy, Injectors. My only other thoughts and i believe you had the same issue is maybe the inake gasket is slipped under the intake in the valley? It is not leaking any vaccum up top at all. It idles 850-950 all day long.

 

[mikestang63]

did you run the codes? Go back and recheck all the vacuum lines, spark plug wires,. It doesnt matter if the tooth is "off" one as long as you can dial in the timing correct you are fine. Either the distributor will adjust to the correct timing or it won't regardless of being one tooth off. You also need to retorque the intake after a few cycles. One of the bolts may have backed out,

If you think the intake gasket slipped, spray some carb/TB cleaner around the perimeter of the lower intake and see if it smooths out.

 

[jcgafford]

not me, i never swapped intakes. did remove the upper and replaced the gasket between upper and lower after painting.

 

[jcgafford]

did you run the codes? Go back and recheck all the vacuum lines, spark plug wires,. It doesnt matter if the tooth is "off" one as long as you can dial in the timing correct you are fine. Either the distributor will adjust to the correct timing or it won't regardless of being one tooth off.

true, poor choice of words on my part. once the dizzy is in you can adjust it with the car running by leaving the bolt just barely loose and rotating it slightly till the engine runs the best.

 

[TOOLOW91]

did you run the codes? Go back and recheck all the vacuum lines, spark plug wires,. It doesnt matter if the tooth is "off" one as long as you can dial in the timing correct you are fine. Either the distributor will adjust to the correct timing or it won't regardless of being one tooth off. You also need to retorque the intake after a few cycles. One of the bolts may have backed out,

If you think the intake gasket slipped, spray some carb/TB cleaner around the perimeter of the lower intake and see if it smooths out.

Already sprayed the intake no leaks anywhere , car idles normal just missing , timing is adjusted to 10deg base spout out , if I don't see something obvious later I am gonna pull the intake and set a new gasket in it because I don't get what else it could be


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[jcgafford]

i had a miss after putting the top end back together. turned out it was a loose egr. i sprayed everything and it never changed rpm. went back and rechecked all the bolts and found it.

 

[TOOLOW91]

i had a miss after putting the top end back together. turned out it was a loose egr. i sprayed everything and it never changed rpm. went back and rechecked all the bolts and found it.

Will look into thanks man ! Just looking for ideas while work is slow today lol only so much you can milk a coolant level sensor out for haha


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[jcgafford]

Will look into thanks man ! Just looking for ideas while work is slow today lol only so much you can milk a coolant level sensor out for haha


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just saying it could be anything you removed and spraying does not always work. i say redo the install.

 

[TOOLOW91]

just saying it could be anything you removed and spraying does not always work. i say redo the install.

I am going to , I just am gonna poke around anyway before hand , shouldn't take long since all bs work of swapping from intake to intake is done


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[TOOLOW91]

2 fouled plugs and it's alive .... back of intake has a small leak down the bell housing so it has to come
back off anyway to get revealed


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[TOOLOW91]

Re sealed *


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[mikestang63]

2 fouled plugs and it's alive .... back of intake has a small leak down the bell housing so it has to come
back off anyway to get revealed


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Glad to hear you got it fixed.


That is a common place for a leak as the gaskets tend to slip and slide if they are not given enough time to set or get bonked/crimped when laying the intake. Can't say it hasn't happened to me in the past, especially when you mill the intake or heads.. I like to use some threaded rods as studs on the intake corners to set the intake on and then remove the rods once it is set and then replace them with the bolts. I would go back and retorque all the bolts once it goes through a few heat cycles.

Hopefully you didn't use those crap cork end gaskets and either used the blue rubber ones with some RTV at the ends or just a nice bead of RTV and let it set up. I also like to put some red RTV around the water jackets.

 

[TOOLOW91]

Glad to hear you got it fixed.


That is a common place for a leak as the gaskets tend to slip and slide if they are not given enough time to set or get bonked/crimped when laying the intake. Can't say it hasn't happened to me in the past, especially when you mill the intake or heads.. I like to use some threaded rods as studs on the intake corners to set the intake on and then remove the rods once it is set and then replace them with the bolts. I would go back and retorque all the bolts once it goes through a few heat cycles.

Hopefully you didn't use those crap cork end gaskets and either used the blue rubber ones with some RTV at the ends or just a nice bead of RTV and let it set up. I also like to put some red RTV around the water jackets.

Yeah man no cork for me just rtv, when I layed it the first time it made a pin hole and coolant made it past , resealed and today it's good , changed the oil last night , have a set of motor craft plugs to put in today as well , I new it had to be something dumb and I was just mad and missing it , but thanks guys , cars feels stronger up top with the gt 40


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[jrichker]

My favorite trick that saves time and effort is the stay in place gasket. Be sure that you scrape (don't use a wire brush) all the old gasket material off, then clean all the surfaces with acetone or MEK.

When the surfaces are clean, use weather strip adhesive on the head to manifold surface. Also use the weather strip adhesive on the side of the gasket that mates to the head. When you are done, the head surface and the gasket surface that mate together will have weather strip adhesive on them. Follow the instructions on the tube or can and when it gets tacky, press the gasket down on the head.

Clean the area where the rubber rails mount to the block in front and in the rear with more acetone or MEK and do the same trick with the weather strip adhesive that you did to the heads.

Coat the rubber seals and the gasket area around the water passages with lots of Blue Silicone gasket sealer and put it together. Bingo! no leaks, and no gaskets that shifted out of place.

 

[84Ttop]

Leaks don't even think about messing with the right stuff!!