1992 740 non turbo starts hard, bogs, sputters, front-fires
#1
06-26-2010, 10:01 AM
1992 740 non turbo starts hard, bogs, sputters, front-fires
Hi guys,
Glad to have found this forum. I checked the onboard error codes via http://www.matthewsvolvosite.com/for...hp?f=2&t=24944 and found no errors except ones I expected.
My 1992 740 non turbo starts hard, bogs, sputters, front-fires (backfires out the air intake tube), and will stall under full throttle (in park). If I baby it it will rev up OK. If I squirt some gasoline in the intake tube while revving it, full throttle doesn't bog it down.
It started hard before this, but ran fine once warm. Recently started bogging down under full throttle. Bad enough now that I don't feel comfortable driving it.
Replaced plugs and wires (looked serviceable, but I bought it used, so who knows), no joy. Have not replaced distributor and rotor (looks serviceable, but due for a change).
Disconnecting the air temp sensor didn't change anything (but it did register 1-2-2 on the fuel self diagnostic, which is good to know). It also threw 3-1-1 on the fuel diagnostic, but my speedometer is intermittent (I use my GPS for a speedo). Ignition diagnostics threw 1-1-1.
Was told by a mechanic to disconnect the MAF and see if it changed anything. I cannot locate the MAF sensor! The air temp (charge?) sensor is readily visible (first sensor after the air box), but there are no other sensors in the tube up to the manifold, and I see nothing that resembles pictures of the MAF from Rockauto.
Halp!
TIA,
Dave
Glad to have found this forum. I checked the onboard error codes via http://www.matthewsvolvosite.com/for...hp?f=2&t=24944 and found no errors except ones I expected.
My 1992 740 non turbo starts hard, bogs, sputters, front-fires (backfires out the air intake tube), and will stall under full throttle (in park). If I baby it it will rev up OK. If I squirt some gasoline in the intake tube while revving it, full throttle doesn't bog it down.
It started hard before this, but ran fine once warm. Recently started bogging down under full throttle. Bad enough now that I don't feel comfortable driving it.
Replaced plugs and wires (looked serviceable, but I bought it used, so who knows), no joy. Have not replaced distributor and rotor (looks serviceable, but due for a change).
Disconnecting the air temp sensor didn't change anything (but it did register 1-2-2 on the fuel self diagnostic, which is good to know). It also threw 3-1-1 on the fuel diagnostic, but my speedometer is intermittent (I use my GPS for a speedo). Ignition diagnostics threw 1-1-1.
Was told by a mechanic to disconnect the MAF and see if it changed anything. I cannot locate the MAF sensor! The air temp (charge?) sensor is readily visible (first sensor after the air box), but there are no other sensors in the tube up to the manifold, and I see nothing that resembles pictures of the MAF from Rockauto.
Halp!
TIA,
Dave
#2
06-27-2010, 01:41 AM
You probably have the Regina system, since it's a non-turbo. No MAF - or, as Volvo calls it, Air Mass Meter.
You're going to need a book, at least a Haynes or Chiltons, that covers the Regina system. Lots of things that can make it run as you describe - like crap - but I'd start by looking for a vacuum leak..
You're going to need a book, at least a Haynes or Chiltons, that covers the Regina system. Lots of things that can make it run as you describe - like crap - but I'd start by looking for a vacuum leak..
#3
06-27-2010, 06:59 AM
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