volvo penta 7.4 gi runs bad

[villain3dusty]

I recently bought a 1989 chaparral villain and it wouldn't start unless you sprayed carb cleaner in it. It had some bad wiring so I started splicing them back and I got it to start. Wouldn't rev over 2200rpm without studdering and back firing, so I put in new plug wires, pumped out 50 gallons of bad fuel and cleaned the gas tank,also put in new water separator. no difference. Put in a new ignition module and it ran better but not great. Put it in the water and it just Boggs under a load. Just starts missing and backfiring but every once and a while it'll start to pick up (actually plained ones for a second) so before I start pulling injectors I figured I'd ask you guys. Ive been doing research and it says it has a limp mode where it'll only get 2500 rpm,but wouldn't it be a smothe 2500 and not missing?

 

[tpenfield]

Re: volvo penta 7.4 gi runs bad

Welcome to iBoats. . .

I guess you now know why the bot was for sale. . . It sounds like you have done a fair amount with the ignition and wiring. I would check the timing and run a compression test to see if that leads you to any issues.

post back any results and additional info. Is the engine a 1989 as far as you can tell?

 

[Bondo]

Re: volvo penta 7.4 gi runs bad

I recently bought a 1989 chaparral villain and it wouldn't start unless you sprayed carb cleaner in it. It had some bad wiring so I started splicing them back and I got it to start. Wouldn't rev over 2200rpm without studdering and back firing, so I put in new plug wires, pumped out 50 gallons of bad fuel and cleaned the gas tank,also put in new water separator. no difference. Put in a new ignition module and it ran better but not great. Put it in the water and it just Boggs under a load. Just starts missing and backfiring but every once and a while it'll start to pick up (actually plained ones for a second) so before I start pulling injectors I figured I'd ask you guys. Ive been doing research and it says it has a limp mode where it'll only get 2500 rpm,but wouldn't it be a smothe 2500 and not missing?

Ayuh,.... Welcome Aboard,.... I'd test the fuel pressure 1st, 'n if it's pumpin' at spec, I'm guessin' the injectors probably Need cleanin',....

 

[villain3dusty]

Re: volvo penta 7.4 gi runs bad

Motor seems to be around a 1999. It's got a new high pressure pump. If nothing else I have an intake and carb laying around I can throw on there and for the price I'm definitely not disappointed

 

[bruceb58]

Re: volvo penta 7.4 gi runs bad

Your first post said 1989 and now you say 1999. Can you take a picture of what you are working on and also get us a model number?

 

[villain3dusty]

Re: volvo penta 7.4 gi runs bad

The motor is around a 99 boat is a 89,where can I find the model number?

 

[villain3dusty]

Re: volvo penta 7.4 gi runs bad

 

[villain3dusty]

Re: volvo penta 7.4 gi runs bad

 

[Scott Danforth]

Re: volvo penta 7.4 gi runs bad

need pics of the motor.

a serial number would be best.

something is not adding up.