• Advertisement

4JB1 low power

Get help fixing your Isuzu from other club members

4JB1 low power

Postby magicdeo » Sat Aug 13, 2016 12:56 pm

Gday. I have recently suffered low power in my 2.8 rodeo. The injectors are only 40 000kms old and the IP was rebuilt 5000kms ago. The power was fine after the IP was rebuilt but has since lost some power. I have changed the fuel and air filters and blew out a blockage in the fuel tank breather which hasnt made a difference. I also jacked up all 4 tyres and spun them and none of them are dragging. The car idles fine and will run all day, just low on power. I dont have a boost gauge so I cant check the turbo boost but I can hear it spooling up. The engine doesnt have any other mods apart from a catch can and a 296 CAV style filter instead of the standard type. Any ideas what it could be?
Cheers
magicdeo
Isuzu Junior
 
Posts: 147
Joined: Mon Nov 24, 2014 9:35 am
Age: 21
Country: Australia
City: Newcastle
Vehicle: 1997 Holden Rodeo

Re: 4JB1 low power

Postby geeves » Sat Aug 13, 2016 2:39 pm

Check the pipe on the top of the pump to where it joins the intercooler or inlet pipe. I had that pipe split and performance went very flat despite still having good boost. That pipe sends a boost signal to the pump and if the pump doesnt recieve it it supplies less fuel
Sanding your knuckles before starting work can help. That way you cant skin them
User avatar
geeves
Site Admin
 
Posts: 8964
Joined: Sun May 10, 2009 1:36 pm
Location: Rangiora
Age: 63
Country: NZ
City: Rangiora
Vehicle: 94 bighorn 4jg2
2013 Subaru XV

Re: 4JB1 low power

Postby magicdeo » Sat Aug 13, 2016 5:49 pm

Thanks geeves. Yesterday i also noticed mine also had a small split right at the end. I replaced it but they didnt have the right size hose. The hose i bought is slightly too big could that make a difference? Also maybe the hose clamps arent quite sealing it properly?
magicdeo
Isuzu Junior
 
Posts: 147
Joined: Mon Nov 24, 2014 9:35 am
Age: 21
Country: Australia
City: Newcastle
Vehicle: 1997 Holden Rodeo

Re: 4JB1 low power

Postby geeves » Sun Aug 14, 2016 6:26 am

It doesnt take a lot of leakage to mess it up There are several things it could be
Sanding your knuckles before starting work can help. That way you cant skin them
User avatar
geeves
Site Admin
 
Posts: 8964
Joined: Sun May 10, 2009 1:36 pm
Location: Rangiora
Age: 63
Country: NZ
City: Rangiora
Vehicle: 94 bighorn 4jg2
2013 Subaru XV

Re: 4JB1 low power

Postby magicdeo » Sun Aug 14, 2016 9:15 am

I will check it out. Can you think of anything else it could be?
magicdeo
Isuzu Junior
 
Posts: 147
Joined: Mon Nov 24, 2014 9:35 am
Age: 21
Country: Australia
City: Newcastle
Vehicle: 1997 Holden Rodeo

Re: 4JB1 low power

Postby geeves » Sun Aug 14, 2016 11:00 am

Restriction in air intake ie filter etc
restriction in exhaust ie cold start device stuck on damage etc blocked muffler
timing moved
tappets loose
wastegate stuck open
turbo not free spinning
loss compression
blocked fuel filter blocked vent in fuel tank
etc
Sanding your knuckles before starting work can help. That way you cant skin them
User avatar
geeves
Site Admin
 
Posts: 8964
Joined: Sun May 10, 2009 1:36 pm
Location: Rangiora
Age: 63
Country: NZ
City: Rangiora
Vehicle: 94 bighorn 4jg2
2013 Subaru XV

Re: 4JB1 low power

Postby magicdeo » Sun Aug 14, 2016 5:57 pm

Ok thanks geeves. Will try work it out
magicdeo
Isuzu Junior
 
Posts: 147
Joined: Mon Nov 24, 2014 9:35 am
Age: 21
Country: Australia
City: Newcastle
Vehicle: 1997 Holden Rodeo


Return to Engine

Who is online

Users browsing this forum: Google [Bot] and 10 guests