First I'll tell what Ive been going thru this week and I'd like to hear any and all opinions on what to do next. Its a 78 F150 4x4 351M all stock except lift/tires. Just had it a few weeks its been runnin great but last friday cruisin down the interstate at 60-65 and it coughed/hiccup but kept runnin and I made it home fine but was a little concerned. Well Sunday I pulled home after a 20 mile or so drive and got out and antifreeze was puking out of the overflow. So I put new top rad. hose and thermostat in it. Still puking and really cutting out and running rough. So I put a new bottom hose and put a new water pump in it. Now its only puking a little but its running like total CRAP almost like its on 4 cylinders. No power at all. Well i take it up to my buddy at Goodyear he does a compression test says all looks good, he says I need a new intake gasket is all. I was actually relieved I was afraid it would need head gasket or worse. Does this sound right given the symptoms I have described? And if so I guess now is the time to get a nice edelbrock 4barrel carb and intake, right? When I buy my new carb/intake should I go non-EGR or stick with the EGR?

Thanks for the advice.

 

Sounds like a typical timing chain skip or ignition module to me.

If the 400 has over 80K miles on it check the timing chain slack with the process in the service manual. Replace the timing chain with a aftermarket multi-keyway setup set at "0". Running like crap will increase the amount of heat the engine produces and will sometimes overload the cooling system.

Otherwise a bad ignition module can also cause similar symptoms. Have it tested at a parts store. Replace it with a genuine Motorcraft module if necessary and mount it on 1/4" standoffs for cooling.

Occasionally a lean condition in the carb can cause overheating. A sudden shift of crap in the carb could cause the cough/hiccup.

Make sure you replaced the thermostat with the correct ~195°F thermostat for a 335 engine. It takes a special thermostat.

 

check the distributor gear roll pin. it can be broken but still hanging on inside.

 

Ditto on the dizzy. Check your timing with a light. If it's off you have the timing chain or dizzy problem.

 

Thanks for the responses, it sure is frustrating to have a broke down truck and not sure whats wrong.

OK well I guess we'll put a timing light on it, and if its off I got either dist. or timing chain problems, right?? We had a timing light on it less than 500 miles ago and it was OK but I will check it again.

According to the mechanic at Goodyear I got a bad intake gasket. Maybe he was just wanting to do the job and make some $$$ who knows. But my buddys got a brand new 4barrel Weiand intake manifold and a brand new 4barrel Edelbrock 600 carb that hes willing to let go pretty cheap, so thats all going on my truck this weekend. That'll get a new intake gasket in it anyways.

Hopefully theres no dist or timing chain problems and the bad intake gasket was causing it to run bad. Is this at all possible or am I wishful thinking????

Also the new carb/intakle is non EGR if that matters at all.

 

Yes, it does matter. You will have to recurve the distributor if you remove the EGR, or you will have pinging.

You should replace the timing chain and install the new chain 'straight up'.

 

What chain do I buy and where can I get it?

 

You want a good double roller 'True Roller' Timing Set. That includes the Cam and Crank Gear. Cloyes makes a good one. You should be able to get one at any good auto store. Make sure it has three keyways. One is 4 degrees retarded, the second is 'Straight up' and the third is 4 degrees advanced. You should use the 'straight up' key.

 

Well I been wrenchin on the old girl all weekend and we made some good progress but now a whole new problem arises. We got the new carb/intake put on there and got everything hooked up and.....she fired right up and ran extremely well. Had to pull the top part off that Edelbrock carb to adjust the floats and then it was running AWESOME. So we drove up to town to put some gas in her, 2 miles up the road and it died in the parking lot. So we jump out and make sure its getting fuel. Everything looks good it just wont start then the BRAND NEW one week old starter goes out. So I pay 40 bucks to get her towed back home, get a new starter put in and theres just no fire at all. Everything is hooked up right but the vacuum advance is loose inside the dist. cap. So I guess tomorrow we will buy a new distributor, coil, and have the ignition module tested and replace if necessary. If none of this works I think theres a wiring problem somewhere and I'll have to have a pro chase it down. Any thoughts/ ideas????????

 

I assume it cranks, but no spark.

Look at one of those DUI distributors.

Is the oil Pressure OK? You should see some oil pressure while cranking.

 

Yea it cranks but no fire. Tell me more about the DUI distributors vs the stock one......price, performance etc...

 

Here is the link. They are a little expensive.

http://www.performancedistributors.c...stributors.htm

 

i'v been running a cheaper vesion of the dui from pro-comp and another silent maker without any problems yet. paid $90 for one and 100 for the other to my door and can't remember how much for the third- some nut was selling them for $56 on ebay but they were bought out and now go for over 100.

So I imagion you might find some of those around and I'd caution you not to use one if you have to worry about egr-unless you get a spacer for the carb that allows for egr (which is farily common and not to spendy.)

Eric has just about convinced me to run a rebuilt stock unit on my new 400 propane build. I have had some issue of hot restart due to increased compression on a windsor build that is a 9:1 and change with a stock cam. But i run 87 without any problem. single wire is hard to argue against.

The ford unit has an automatic retard on start that helps with restart. I really dislike the wiring on the ford unit but didn't take the time to learn it either. If you have a problem it can be just about anywhere and is not usually a bad brain box. The wires become compromised somehwere and the chase is on. Connections seem to go bad on my rigs.

I think for everyday running the stock system is probably the best deal if you can figure out how to test it and fix it on the go if needed. But I have a couple more cheapie hei systems that i'll run until I can find all new wiring and convince eric to rebuild a custom distribuor for me.