Rough acceleration?

[chris142]

A customer brought me an 87 F350. It's got a 6.9L with a Banks Turbo. He bought the truck not running, Bad Injection pump he was told. He got a pump from Autozone : : and got it running. He brought it to me so I could time it.

The timing was very retarded. My timing light is not as awesome as Gary's but I've got the timing somewhere between 8* and 9*. The truck has an auto trans. I take off foot on the floor , it makes 15ft of coal then falls on its face. It gets to about 2000rpm and it starts to sputter. If it was a gasser I'd say it had bad plug wires or plugs. It spits and stumbles to 3300 rpm or so then shifts.

So I'm wondering. Bad/unmatched injectors? (they are "B" codes) or could the turbo be opening the intake valves too early? Any other ideas?

Oh I put a new fuel filter on it. that helped some.

 

[vegas39]

I don't understand what you mean about the turbo opening intake valves too early, no connection there.

You may have a fueling issue, I'd check to make sure the lift pump was doing its job, also check the fuel filter. Pickup assembly in the tank should also be checked.

I wouldn't trust an Autozone injection pump any further than I could throw it!

How old is the fuel, the filter may be plugged again if the tank is real dirty.

 

[79jasper]

Valve lift aka valve float is when boost or exhaust pressure overcome valve spring force.


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[vegas39]

Valve lift aka valve float is when boost or exhaust pressure overcome valve spring force.


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I see now.

 

[FarmerFrank]

Mines been doing that but the lift pump is on its way out. Check fuel pressure to the injection pump

 

[chris142]

Thx. I'll ck pressure and report back. Prolly tues or wed.

 

[Zxmazza]

You say it blew 15ft of coal and "choked". I would be concerned about lack of air first, check to make sure theres nothing wrong with the intake in terms of blockages, if not an issue id be looking towards the fuel screw on the new ip immediately; probably set wide open out of the box.

 

[chris142]

K&N air filter is clean. Has 4 psi of fuel pressure at that tire stem looking thing with it running and tons of volume. I pressed on the Schrader and it shot fuel almost to the other valve cover.

The truck sat 2 days behind my shop. Started right up this morning. No burping or farting.