Ignition Problem?

Hi All, first post here. I recently bought a 1990 Ram that seems to have some type of ignition problems (my speculation anyways). Under heavy throttle application the engine bogs, I tried adjusting the timing, although I'm not sure I got it right. The emissions tag says 10 BTC, but both the block and harmonic balancer have scale on them. I tried setting the 10 BTC on the balancer to the 0 on the block (idles poorly and will stall in gear if brakes applied), next I tried setting the 0 on the balancer to the 10 BTC on the block (idles nice but is gutless under throttle and bogs still.)

Also there have been a whole host of other mods:

Converted to run propane
Converted back to run gasoline
Headers with dual exhaust
Holley throttle body
Looks like the EGR valve is gone and blanked over.

Any input would be appreciated. Thanks

sometimes you got to play with the timing. might have to run at about 8* or 12* since there is most likely slack in the timing chain. also is there an oxygen sensor somewhere in the exhaust? i know sometimes when someone installs headers and duals they think the truck will run fine without it but it will not.

I'm not sure what marking to use to set the timing, the harmonic balancer has a scale marked 10 BTC down to 0 then down to 10 ATC, the block also has a scale from 10 BTC to 0 then to 10 ATC. What markings are supposed to be aligned? It does have an O2 sensor.

I'm at a loss on the timing thing.

just go with the ones on the block. stock timing only works good when the engine is new and there is no slop. with time stuff stretches. you got to play with the timing a couple degrees. most times i don't even bother with a timing light. just adjust it a bit and test it out and see how it does.

Update: I've tried every combination of timing adjustment I can figure out. No fix.
New cap and rotor, no fix.

My next change is the fuel filter (had a few guys suggest this) so if this works.

I've read about other guys with the Holley 3443 Throttle body having similar problems but have yet to find a solution.

Could it be something else like a clogged catalytic converter? Don't know if you still have one.

Won't be the converter, it's been gone long before I got this truck. From what I've read about this seems to be a symptom of low fuel pressure, so I'll eliminate the filter as the problem. If that doesn't do it I'll pull the pump.

Update:

It appears to have been a poorly seated plug, either the TPS or the MAP, I had unplugged them when I installed a new plug on the harness for the oil pressure sensor. It's now running like a top again.

Well, i thought it was running like a top, but its not. My next theory is that because the previous owner put a dual exhaust on it but it only has one O2 sensor, which is only reading from one bank is causing it to run too rich.

any suggestions? Thought about putting a crossover pipe and having the O2 sensor at the center of the cross, or if there is a way to parallel the O2 sensor and install one on the other side?

i don't think there is any way to run dual o2 sensors. if you new enough about electrical you could probably stick a resister in the 1 wire to possibly compensate for running true duals but you need to know exactly what size resister you would need to get it back in the right ball park. have you tried pulling codes to see what the computer is saying? if it is running rich the computer should have a code stored in it.

crazzywolfie said:

i don't think there is any way to run dual o2 sensors. if you new enough about electrical you could probably stick a resister in the 1 wire to possibly compensate for running true duals but you need to know exactly what size resister you would need to get it back in the right ball park. have you tried pulling codes to see what the computer is saying? if it is running rich the computer should have a code stored in it.

Click to expand...

That's the thing, no code. I think because the O2 sensor is only reading one bank, its always sensing that it lean so its running as rich as possible. Also the previous owner had removed the re-heater from the exhaust to the intake (which also tells it to run more rich.)