is the pump the problem?

[HondaEater]

The truck still runs fine at idle but wont accelerate. i replaced the pump. there was a yellow wire that ran back towards the distributor to its own connector that wasnt connected, looks like someone snipped it (i think this is the vacuum advance) so i just cut the connector and spliced the twice wires together. idle went up. sounded like it did before. but i drove it and it still runs the same. wont accelerate. sounds like theres a dead spot. this is my daily driver and i need it to get to work everyday. someone heeelp

 

[OilPatch197]

The truck still runs fine at idle but wont accelerate. i replaced the pump. there was a yellow wire that ran back towards the distributor to its own connector that wasnt connected, looks like someone snipped it (i think this is the vacuum advance) so i just cut the connector and spliced the twice wires together. idle went up. sounded like it did before. but i drove it and it still runs the same. wont accelerate. sounds like theres a dead spot. this is my daily driver and i need it to get to work everyday. someone heeelp

Hmmmm! I got a 1984 Ranger with a 2.8., surprised you didn't comment on how stupidly hard it is to change that pump!

Some things to check (good find on that wire)

Do you get any Throttle position sensor codes? (could be a dead spot in your TPS, but if no codes it should be tested with muti-meter(steadily increases in resistance with no dead spots)

Are you running clean fuel, and you DID replace the fuel filter with that pump change? (My dad works for Airtex, a Fuel pump maker here in the USA)

Is your Accelerator pump linkage connected or out of adjustment?(it has a summer winter adjustment slots, and I've had them pop off before, making it a bitch to start)

Also you COULD have clogged jets, when my truck got some contaminated gas(rust particles) it clogged up those two jets, the power valve and a carb rebuild restored most of the power, rust had plugged up the jets and how that rust got past my fuel filter I will NEVER know(1mm chunks made it through!)

I upgraded my fuel pump to electric: http://www.oreillyauto.com/site/c/detail/ATN0/E8090.oap?mn=Airtex&mc=ATN&pt=N0515&ppt=C0128

after my Purolator started sticking when that rusted fuel was pumped through the thing, I've learned a hard lesson, you need a name brand in a fuel pump, and don't trust a used sending unit. There is a lot of crappy cheap "mr gasket" fuel pumps out there, and if you bought your mechanical pump from Autozone, it's a Master brand of a Airtex pump.

 

[HondaEater]

It was a pita but I have larger problems right now Can't complain about a hard wrenching job. Let me try to answer all of your questions

The pump is an airtrex pump. I did get a tps code. I did replace the fuel filter (right in front of the air cleaner) I looked for the one on the frame rail but now I'm asuming that's only for efi vehicles. I don't know much about carburetors so I couldn't tell you about the accelerator pump.

 

[OilPatch197]

http://www.autozone.com/autozone/pa...mString=search&itemIdentifier=132993_40353_0_

That is the TPS, and that connector located on the pass side of carburetor.

It's hard to say, the ECC-IV is a complex system, I would test that TPS sensor.

It MAY have a dead spot allowing the engine to cut out

To test that sensor you would probe two of the three wires, as you open the throttle the resistance should change, gradually(with no spikes or dead spots) I can't find the info, but I THOUGHT the Autozone site had testing info for that sensor, but I can't find it.

It is a fairly expensive sensor, and since we have people like me running duraspark on their 2.8's, it might not be the culprit.

I would also check to see if your carb is shooting gas into the throat of the carb, simply shut off engine, take off air cleaner assembly, and move the throtle, that should shoot gas through two passages into the throat of the carb.

I suspect you just need a carburetor rebuild.

I would also check to see if plenty of fuel is being pumped out, just loosen your gas tube at the fuel filter, and if plenty of gas is pumping out, then it is good.

I would also check your base timing(with that yellow wire unplugged) and set it to factory spec.

 

[HondaEater]

The two jets are squirting plenty of fuel

What does the tps even controlled on a carbureted car. There's no fuel rail or injectors so its not like the tps is used to determined injector pulse width air fuel ratios etc

Its on the passenger side of the carb?? All I see on that side is the electric choke assembly..

I already did a fuel pressure test it was getting plenty of fuel flow. Timing was set 10 degrees BTDC.....

 

[OilPatch197]

The TPS controls your IAC!!!

That's the Idle Air Control valve.

Can you describe your symptoms in detail, like what happens when the engine is Idling and you gun the accelerator to the floor?

Does it do it when transmission is in drive?

 

[kimcrwbr1]

Actually the TPS controls the egr position and the advance of the dizzy. You can disconnect the egr vacuum and hook it to manifold vacuum at an idle the engine should stall. Just thinking about it you may be having problems with the knock sensor. That retards the timing under a load. It is in the block down by the starter and the connector usually gets pretty dirty pull it apart and clean it good with electrical cleaner and use some dielectric grease to put it back together. The easy way to test it is to tap on the block next to it with a wrench while your looking at the timing with a light. Dont tap on the sensor they are brittle. The timing should retard as you tap.

 

[HondaEater]

Its got a flat spot, a mean one at that. Before it felt like it wouldn't rev past a certain rpm. Now it'll rev way higher but its sounds like its choking. In gear it falls flat on its face then recovers and takes forever to get to ten or fifteen miles per hour in first. As it stands right now it'll only do about 35 in fourth tops. It doesn't backfire out of the carb. Doesn't snap crackle or pop. Motor doesn't shake violently.

Also. In the wire loom that runs to the distributor I have an unidentified, unconnected wire. I followed the wire as far back away from its end as I could and it was completly bare so I have no idea what color insulation the wire had. The other wires are black green blue two reds and the yellow wire. Then again. The yellow wire and this new found wire were problem disconnected when I bought the truck so I don't know if they're going to be the problem solvers (like I said hooking up that yellow advance wire didn't help much except for at idle it bumped the idle speed up)

 

[HondaEater]

In conclusion, it ended up being a clogged catalytic converter. thanks for all those that helped!

 

[OilPatch197]

In conclusion, it ended up being a clogged catalytic converter. thanks for all those that helped!

Ah, back pressure! I have not had a cat on my '84 for years, it is of course a "off road" vehicle, in case anyone screams bloody murder..

 

[kimcrwbr1]

Did the fuel pump work if not check the exhaust system for flow hold your hand in front of the tailpipe and have someone goose it if there is little change in flow with rpm probably a clogged cat or muffler.