79 Econoline 351 - no power uphill and rubber smell

[Paisley777]

Hello all,

1979 Econoline, 5.8 351
only 9mpg (had been getting 12 before the 37yo dirty tank was allowed to run nearly dry and fouled everything up)

I've been trying to chase down this issue for some time. Got my 79 2 years ago - leaking oil like a sieve, overheating, no power - the whole 9 yards.

Engine rebuilt last year. All else good except it still loses it's butt up a hill. ('hill' here in NM is mountain)

Since last year - new tanks, lines, filters, pump, rebuilt carb (though I suspect it needs it again from allowing old tank crud in ~after~ the rebuild

). New radiator & trans cooler. (no more overheating in 100+ temps)



So, this weekend I took her on a shake down. About 3 hours each way. 100deg out and mountains.

Mostly ok but...
-drops to 55-60 uphill with foot all the way to the floor.
-just before hitting its highest output it sounds like it really, really working hard, barely making 60, then it sounds like ~something~ kicks in and starts to get more power. Can really hear a switch over in the engine sound.
-smells like burning rubber under those conditions.

Thoughts?

ps - at one point about 200 miles in, it lost all power. Felt like when a fuel pump goes out. I let off the gas - got some power. Foot down - lost power. I stopped, put in park & revved her up a few times. All cleared up after that. No problem before or after. Maybe just some junk in the line and a one off? unrelated to the more chronic hill trouble?

Any help would be appreciated. I have to leave for CA in 2 weeks!

 

[Gary68]

does it idle and rev smooth? or is it rough,missing or stumbling?

i would start with
clean air filter,check that butterfly in the exhaust make sure it is opening,if it has one,and set the timing

rubber smell i would check belts and see if anything is near or on your exhaust

 

[highdesertranger]

couple questions. what type of Carb? how much does your vehicle weigh? what does the trans fluid look like? do you see any smoke in your mirrors when you smell the rubber smell? highdesertranger

 

[Paisley777]

does it idle and rev smooth? or is it rough,missing or stumbling?

i would start with
clean air filter,check that butterfly in the exhaust make sure it is opening,if it has one,and set the timing

rubber smell i would check belts and see if anything is near or on your exhaust

Very smooth otherwise. 

Butterfly in the exhaust?  I only know about the carb butterfly.

The smell only comes with going uphill.  Not dependent on any other factor.

 

[Paisley777]

couple questions.  what type of Carb?  how much does your vehicle weigh?  what does the trans fluid look like?  do you see any smoke in your mirrors when you smell the rubber smell?  highdesertranger

Carb: not sure about brand, but stock 2B

Weight: I added a fiberglass high top/removed the steel roof, removed the std seats and added2x2 framed cabinets and no sides. Basically frames.  Point is, it doesn't weigh much different then standard

Cleaned the transmission last month.  My mechanic friend helped.  He said it looked pretty good.  The fluid was old but no large metal bits.

I did notice smoke when I pulled over and revved it up.  Didn't notice on the hills

 

[ZoNiE]

New Mexico? High Altitude...

 

[Paisley777]

New Mexico? High Altitude...

Yes it is

 

[Gary68]

i have had them stick on me,car ran just fine but when you got on it,nothing,i remove them

when they rebuilt the motor did the put in a rv cam? if so you might need more carb,a edelbrock intake and 600 carb has improved everything i have put them on

follow up on the trans angle,if its slipping it could be your lack of go and smell

 

[Dennis]

Change out fuel filters, inline and carb, and see if that helps with power issue.

 

[Paisley777]

i have had them stick on me,car ran just fine but when you got on it,nothing,i remove them

when they rebuilt the motor did the put in a rv cam? if so you might need more carb,a edelbrock intake and 600 carb has improved everything i have put them on

follow up on the trans angle,if its slipping it could be your lack of go and smell

"i have had them stick on me"
What is 'them?'  The thing in the pic?  (I am self taught, so if I haven't had to fix it yet I likly don't know what it is yet.  : )

"hen they rebuilt the motor did the put in a rv cam"
Yes, I think so.  He said he knew I have a trailer I two sometimes, so he said he put in a cam for towing.

"more carb,a edelbrock intake"
I don't understand

As for trans - I had read that the rubber smell could be clutch but they were talking about manual trans.  Can an auto also do that?

 

[highdesertranger]

ok lets see 2bbl carb + no computer + high elevation = 55-60 not bad. I myself would not push it so hard on the upgrades back of the foot to the floor try 45-55 mph. now on to the rubber smell you could be overheating you transmission. where is the smoke coming from? your weight cannot not be close to stock with all you have added + your gear you are way heavier than a bone stock van empty. weigh your van and compare to the numbers on your weight plate. do you have an aftermarket trans cooler? highdesertranger

 

[Paisley777]

ok lets see 2bbl carb + no computer + high elevation = 55-60 not bad. I myself would not push it so hard on the upgrades back of the foot to the floor try 45-55 mph.  now on to the rubber smell you could be overheating you transmission.  where is the smoke coming from?  your weight cannot not be close to stock with all you have added + your gear you are way heavier than a bone stock van empty.  weigh your van and compare to the numbers on your weight plate.  do you have an aftermarket trans cooler?  highdesertranger

As for weight, It had thicker cabinets, a bench seat, two other bucket seats, and a cooler/sink... all that was removed.  That is what I was comparing to, not empty.

If 50-55 is reasonable then I'll accept that.  It just seemed weak for a 8cy but I have no trouble being wrong. 

Yes, I have an after market trans cooler.

 

[Patrick46]

A 2BBL carb is not enough fuel for a V-8 mil pulling a big hill in a full size van. You need a smaller 4BBL in my book.
I bolted a Edelbrock 650 in my panel truck, and that was the last time I ever touched it.

Also...don't put your foot on the floor like that. You're gonna overwork your new engine...and that'll severely shorten it's life span. (which is why you rebuilt it in the first place...right??) Be nice to the equipment!

The rubber smells??? Recheck the tightness of your belts.


btw...that 'thing' is an exhaust manifold heat riser valve. It stays closed to add back-pressure to the engine to help with cold starts, and it gradually opens as the engine warms up (via thermostat spring)...unless it's rusted shut! Then it plugs off the exhaust system!!! (engine no runny!)

 

[Paisley777]

A 2BBL carb is not enough fuel for a V-8 mil pulling a big hill in a full size van. You need a smaller 4BBL in my book.
I bolted a Edelbrock 650 in my panel truck, and that was the last time I ever touched it.

Also...don't put your foot on the floor like that. You're gonna overwork your new engine...and that'll severely shorten it's life span. (which is why you rebuilt it in the first place...right??) Be nice to the equipment!

The rubber smells??? Recheck the tightness of your belts.


btw...that 'thing' is an exhaust manifold heat riser valve. It stays closed to add back-pressure to the engine to help with cold starts, and it gradually opens as the engine warms up (via thermostat spring)...unless it's rusted shut! Then it plugs off the exhaust system!!! (engine no runny!)

I've already started pricing 4bbl carbs.  <sigh>  I'm finding >$400, so I have to wait.

Yeah, I sure didn't want to floor it like that.  It's no habit to be sure!  I run 60-65 on the highway.  No interest in being speedy.  I was intentionally pushing the boundaries  on this trip.  I wanted to find any problems here, close to home base, instead of halfway to Cali.

Is is possible that it's going into a higher gear late?  I hear the engine sound change in a very distinctive way after a min or so of chugging up the hill.  After the change it then starts to show more power & sounds like it's working less.  I let off the gas and it drops back to the sound like it's working harder.  Like on a manual when you need to shift. 

ah.  Good to know about the heat riser.  Thanks.

 

[Gary68]

you would need an intake manifold and carb,swap meet,ebay, craigslist,i got my last edelbrock carb and manifold off ebay for $300 + 60 for a carb kit

do you have an overdrive transmission ?

 

[ArtW]

sorta starting to sound like the torque converter isn't unlocking when it should (if it has a lockup TC)
what transmission does your van have? AOD? C6?

 

[Paisley777]

Crap. I am woefully unaware of trans info. How can I find out what it is, overdrive or not, etc? ... I do believe my mechanic mentioned 'c6' when we got the gasket kit.

only 300 for both? I'm looking in the wrong place or at the wring thing. I was seeing on ebay 400+ just for the carb itself. I am aware that I'd need a different intake as well.

 

[ArtW]

I think if it's OD it'll be indicated on the shifter panel (don't hold me to that) If it's a c6 it's vacuum modulated IIRC, so check the vacuum going to the modulator
as for the torque converter I'm not sure if a 79 has a lockup TC or not, but usually they are electrically controlled I think
I mostly worked on GM product so I'm not fluent in Ford
HDR will be much more helpful here I'm thinking, as he is still wrenching for a living and has knowledge of a wider range of vehicles than I do
you might try manually shifting to 2 when pulling a big hill and see what that's like

 

[Paisley777]

A mech friend just said he thinks it's staying in 2nd and not kicking into the 'passing' gear until late in the climb.

So I'm wondering if that is the way it should be, can it be/should it be adjusted.

This of course is how I start to learn about these parts & repairs. Guess it's time to learn how auto trans work. :/

 

[Gary68]

http://www.ebay.com/sch/i.html?_odk...S0&_nkw=edelbrock+carburetor+600+cfm&_sacat=0

1405 is manual choke,1406 is electric


http://www.ebay.com/sch/i.html?_odk...w=edelbrock+intake+manifold+ford+351&_sacat=0