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Stumble when goosing in in 4th 89 Renix 4.0

C

ComancheColt

NAXJA Forum User
Location
Southeastern Ontario
With no load, it wont stumble if I gently rev, or pound on it. In 3rd and 4th gear, if I give it a good shot to bring it up to shift point, it bogs down and stumbles like its flooding. 397,000KM on the entire drivetrain.

Any ideas as the cause? Ive had a friend follow me and he says he cant smell any unburnt fuel.
 
Check and make sure the EGR valve is functionong properly or with that mileage just replace it.

I had issues with the Knock sensor retarding timming for no reason on hard accel. I just unplugged it and have had no issues with det/valve ping. I think I'm getting slightly better mileage and a lot more power on accel. If everything is in good shape and you run good gas you may be able to go with out the knock sensor.
 
chadd_raylee_389@h said:
is it safe to unplug the knock sensor? im not being a smart ass i just dont know
Click to expand...

As long as the engine is in good tune and you run good gas. The 91+(OBD1/2) do not have it or any other means of detecting detonation that I know of.
 
Where's the knock sensor on the block anyhow?

Ive got a harsh, loud exhaust, and it will normally only do it after I ran down a hard rough road or if the exhaust is resonating off the frame and underbody.
 
knock sensor is on the drivers side of the block, about half way back, just above the oil pan rail. IIRC, it has a shielded wire covered in an aluminum sheath
 
Yeah, no dice on the clogged air intake.

So what should I be looking at now? Ive got a new gascap, checked all EVAP lines and everything, nothing seems to be helping.

When I get paid friday, Im going to fill it up. If it stops doing it, then I should be looking at Fuel Pump.

Anyone have any ideas? Its also got a high-idle.
 
ComancheColt said:
where would I find the EGR? Under the heatplate that sits ontop of the intake manifold between mani and injectors.
Click to expand...

its attached to the side of the intake manifold under the intake tube. it will have a vacuum line running to it
 
In this pic the EGR is the round shiny thing on the side of the intake, dead center. Unplug the vacuum line there at the round black thing and plug it with a golf tee. Go for a drive and see if the stumble goes away.

BTW, This is a pic of the engine in my 90.

engine2wb9.jpg
 
I found the issue with the stumble.

PO said that he bent the pickup on the pump when he installed a new tank. Bent it toward the front of the WarWagon, so I pinned it to only doing it when I get it in those gears due to the slung-back force and whenIm heading uphill.
 
ComancheColt said:
I found the issue with the stumble.

PO said that he bent the pickup on the pump when he installed a new tank. Bent it toward the front of the WarWagon, so I pinned it to only doing it when I get it in those gears due to the slung-back force and whenIm heading uphill.
Click to expand...

did you fix the problem or is this just what you think it is?
 
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