I was out for a ride today in my 87 D150 and it started bucking and jerking violently.I tried to give it more throttle but when I did it would nose over and almost shut off.I managed to get home at 10 mph.It has all new tune up parts and filters.I still have the ESA hooked up but the vac line is disconnected as it does not advance timing as it should.

First thing that comes to mind is a secondary ignition fault- weak coil output, arcing thru the rotor under hi load (new parts can still be bad). I'd use a spark tester & see if you get a big spark at the end of the plug wire. If that's good, I'd check for a gross ignition timing error, or a fuel pressure/carb problem (gross lean run). Another possibility is a broken up/ clogged cat converter.

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63 Valiant Wagon
225 - 4 bbl

If the vacuum line is not hooked up to the ESA computer then the timing and fuel mixture will not function as they should. You need to (A) hook the line back up and (B) determine if the vacuum transducer on the ESA computer still holds a vacuum. If it does hook the vacuum hose up to a source of MANIFOLD vacuum (not ported vacuum like for a distributor). If it doesn't you need to replace it with oner that does.

The ESA system relies on the MANIFOLD vacuum signal to determine the timing as well as the fuel mixture. It is a rudimentary engine load sensing system that MUST be functioning for the ESA to be in any kind of condition other than non-working limp-in mode.

Get the ESA working right and your problem should go away.

When you say the ESA does not advance the timing "as it should" what do you mean by that? What tests have to done to check the timing advance?

I have the timing set at 16 btdc as per the underhood sticker.When I set the timing I revved the engine and it never moved off of the 16 degree mark.I am not sure if it only advances under load or not,so I assumed it was not functioning properly.I unooked the vac line on the side of the road to see if it would run faster than 15 mph.I also put a gauge on the vac line and have 20 hg of vaccum.

The ESc senses the vacc reading and adjusts the timing from that (much like a slightly evolved vacc. advance can on the normal EI vehicles. Unfortunately since the engine demands different "advance" at certain loads/rpm sticking it at 16 with no advance is not going to be good for the engine (which typically if a dual pickup distributor will use the first pick up at 10 degrees retarded from your current static setting, then once the engine 'lights' it switches to the other pick up for your normal static setting, then controls advance from there). Worst case, the 16 BTDC isn't helping the engine at low rpm and the carb is not calibrated for it (is it a late feedback carb?), and at higher rpm you are just getting crappy gas mileage with no extra advance of any kind.

Sounds like it's time to refit the vehicle for a regular EI distributor before things get worse (of course finding a normal carb is going to be the spendy part of the whole operation).

-D.Idiot

The 16 degree setting is what it called for I do have a Clifford intake and headers for this truck.I also have a msd 6a and blaster coil.All I need is a dist. and throttle and kickdown to do the conversion but I was trying to get it to run better till I can do the swap.I am disabled with a heart condition at 49 years old,so I don't move as fast as I used to :oops:My truck does not have the feedback carb it has a 1945.

If its not a feedback carb then IMO I would start with the HEI swap and cut all that ESA (Lean Burn) out. (hope you dont have vehicle inspections) Theres plenty of write ups on here and highly recommended. Start small and work your way up. Start by first getting the spark figured out and running right, As it would only make it worse when you switch to the clifford intake and headers. That keeps from wondering if it is still spark or the new intake/exhaust. Look at it like an improvement and weight savings in one

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225, Offenhauser, Holley 350, A833OD, 3:55, GM HEI,99 Durango starter
BOOSTED! WH1C, BIG FMIC, 10#
Operation Noble Eagle 03-05
Operation Iraqi Freedom 05-07
Operation Enduring Freedom 12- 13

Yes the manual says that, but the manual also is written on the idea that the ESC is fully functional, and it sounds like it's not advancing anything...which puts you in a not so great spot. With fixed timing like that, it's similar to a human being asked to run a few events at a track meet, but the human's pacemaker will only keep his heart beating at one speed-no increase when exertion is placed on the body.

There are a couple of options depending on how you want to go about it.

The cheap and easy retrofit if 'temporary' is to retrofit to a points distributor (no need to buy an HEI or mopar EI module), that might get you buy for a few months while saving up for the kickdown and an EI distributor, and all the wiring etc. needed.

The other way is to install the HEI or Mopar EI system (here you will need either a new or reman distributor for a 1976-1980 vehicle- crap shoot on curve from Cardone.)

I would offer to curve one for you, but I have run out of EI cores and local junkyards don't have this kind of thing anymore...


-D.Idiot

I have thought of getting a reman ESA and doing a carb rebuild,selling the clifford stuff as Delaware has yearly sniffer testing.

After all that it was a slimy,soft collapsing fuel line from the tank to the fuel pump a $2.00 fix

Sometimes it's the simple things that give us the most trouble. Glad you found it. You could have chased that one for a month and not found it.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

Mine does something similar when it's cold, and I did drop the tank to change my leaf springs a month or two ago...might have to check my lines as well. It'd be nice if it was that easy of a fix!

Replacing the fuel line will not correct the fact that the timing is not advancing. You need to either repair the ESA system or convert to a point, electronic, or HEI ignition system. I find it very difficult to believe that a 1987 truck was not originally built with a feedback carburetor. My suspicion is that someone swapped the original 6145 carb out for a 1945. At the very least, reconnect the hose between the ESA computer and the constant vacuum on the carb.

Reed, there were 1945s in 87, as well as 6145s.

I have one in my van (which I inherited from my dad who was the original owner, and I am the first person to ever remove the carb.)

Eggman,

Have you tried attaching a vac line to the ESA, a tach to the coil, and sucking (or vacuum pumping) the vac line and watching the tach?

(also serves to check if it holds vacuum, is clogged, etc)