bugsjeep
04-02-2018, 01:13 AM
Mine is a 90 Renix and as some of may know I had a weird idle (hunting, stumbling) had a hard time finding it until I finally found a tiny....I mean tiny crack in MAP hose at throttle body. I had done the spray around with starting fluid thing no changes anywhere. I finally just replaced the vacuum harness and took the others off to inspect them. With a loop I saw a tiny crack on the inside of the 90 deg bend right out of the throttle body.
I started thinking that because I had already changed the crank sensor, cam sync, IAC and TPS, I thought why not do a full tune on everything.
First I did the ground on the block, added another ground, pulled and cleaned all the relays, tightened intake bolts, soldered the ground wires in harness on firewall.
So, that stuff out of the way I started with the tune....so to speak
New parts list -
air filter
oil filter /oil
manifold air temp (from tomco)
coolant temp
throttle position
idle air control
crank position sensor
cam sync
ignition coil
o2 sensor
egr valve
fuel pressure regulator
fuel injectors
fuel filter
fuel pump
plug wires
spark plugs (copper core)
dist cap
rotor
Well, I think that's it. I know some of it (most) was not really needed, but I know now that March 2018, everything I could think of was replaced. I mean it's all easy stuff to put on, I did put ground wire on pos side to drain the ecu so it could learn all the new parts. If i had to say which was the biggest pain to change I think I would say the cam sync., dumb design, you have to take it all apart just to change the sync. Some say the fuel pump is a pain, but that's easy, jack the back up for room, and I have a wrench I machined for the ring nut.
It had the wrong injectors in it as well, the nozzle end did not go into the small hole going into chamber, only went to bottom of larger bore so spray would have been bad into chamber. New one go all the way through into chamber as they should.
Drove it 160 miles and did 4 1/2 miles to gallon better than I had ever done before all this, so to me, worth every penny.
Long story short, as others have said, that vacuum line to MAP needs to be perfect. I put a fitting in the body and used a 3/16 fuel line (because it's reinforced).
Don't really have a moral to this story, well sort of.....these engines use pretty simple systems, good vacuum lines are the first thing to check.
I started thinking that because I had already changed the crank sensor, cam sync, IAC and TPS, I thought why not do a full tune on everything.
First I did the ground on the block, added another ground, pulled and cleaned all the relays, tightened intake bolts, soldered the ground wires in harness on firewall.
So, that stuff out of the way I started with the tune....so to speak
New parts list -
air filter
oil filter /oil
manifold air temp (from tomco)
coolant temp
throttle position
idle air control
crank position sensor
cam sync
ignition coil
o2 sensor
egr valve
fuel pressure regulator
fuel injectors
fuel filter
fuel pump
plug wires
spark plugs (copper core)
dist cap
rotor
Well, I think that's it. I know some of it (most) was not really needed, but I know now that March 2018, everything I could think of was replaced. I mean it's all easy stuff to put on, I did put ground wire on pos side to drain the ecu so it could learn all the new parts. If i had to say which was the biggest pain to change I think I would say the cam sync., dumb design, you have to take it all apart just to change the sync. Some say the fuel pump is a pain, but that's easy, jack the back up for room, and I have a wrench I machined for the ring nut.
It had the wrong injectors in it as well, the nozzle end did not go into the small hole going into chamber, only went to bottom of larger bore so spray would have been bad into chamber. New one go all the way through into chamber as they should.
Drove it 160 miles and did 4 1/2 miles to gallon better than I had ever done before all this, so to me, worth every penny.
Long story short, as others have said, that vacuum line to MAP needs to be perfect. I put a fitting in the body and used a 3/16 fuel line (because it's reinforced).
Don't really have a moral to this story, well sort of.....these engines use pretty simple systems, good vacuum lines are the first thing to check.