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No Power....

M

[email protected]

NAXJA Forum User
Location
Courtenay BC Canada
Hey guys, So I've been having some problems with my jeep lately. About a week back when I was driving you along you could here the jeep backfiring quietly while giving it a little bit of gas, this gradually got worse. I ended up pulling the front cover off to check the timing and it was still aligned properly. I put it all back together and did a once over on the motor, I noticed that the bolt that holds the distributor was loose to I tightened that down. I fired up the jeep and it ran great, i backed it out of the shed and went for a spin. The only problem now is there is NO power, it just bogs down and will backfire. The only way you can get going any were is by lots of skinny pedal. The jeep is a 88 with the 4L and AW4. It has new Cap, Rotor and Plugs as of late November. I have a Wire set and O2 sensor on order to see if that makes any difference. I'm thinking its running rich (puffing black smoke when you rev it up)..... Any Thoughts?


Matt
 
The rotor in the distributor needs to be lined up with the #1 post in the cap when the timing mark on the harmonic balancer is at firing point for #1 cyl on the compression stroke. Do you know how to do that?
 
Check your fuel pressure and test the EGR.
 
Well i re indexed the distributor and it might have cleaned it up a little bit. I let it idle for maybe 15 mins i shut it off came inside for a few mins and then started it back up and now it idles at about 1700rpm and its idling with just the right amount of gas that it is backfiring really loud at idle. EGR tested out fine.... Dont have a fuel pressure gauge at the moment ill try and borrow one form work tomorrow.

Matt
 
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The high idle is gone now and it is idling at 7 or 800 rpm now. the idle will pulse thought. sit at 7 or 800 then go up to about 11 or 1200 then drop back down. it will sit at 7 or 8 for maybe 30 seconds then go up to 11 or 1200 for about the same...
 
Try pulling the IAC and clean it and the throttle body, use a TB-safe cleaner.

Once it is back together you should test and adjust the throttle position sensor.
 
[email protected] said:
I did clean the IAC and throttle body with throttle body cleaner. How do i adjust the throttle position sensor?
Click to expand...

Go here: http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

Bookmark the page, you will need it again and again.

Scroll down to the TPS. The only thing I would add is when you are checking for the .8 volts with the harness attached to the TPS you need to "back probe" the weather guard connector--use two small paper clips straightened out for the probes.

Also, repeating about the GROUNDS. They will make a Renix guy's life miserable. Battery to engine block, dipstick tube, back of head to firewall. The head-to-firewall is the ONLY ground for the unibody, it really needs to be in excellent condition.
 
joe_peters said:
They will make a Renix guy's life miserable. Battery to engine block, dipstick tube, back of head to firewall. The head-to-firewall is the ONLY ground for the unibody, it really needs to be in excellent condition.
Click to expand...

Not on mine any more. When I made 2ga upgraded battery cables I added a 4ga one directly from the battery to the body by the battery. :)
 
Ok, I'll do that tomorrow. Just throwing it out there, but could a head gasket give me these problems? A few of the guys from a local 4x site are thinking it could be the crank position sensor, what do you think?
 
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[email protected] said:
Ok, I'll do that tomorrow. Just throwing it out there, but could a head gasket give me these problems? A few of the guys from a local 4x site are thinking it could be the crank position sensor, what do you think?
Click to expand...

The CPS pretty much either works or it doesn't.

The problem is that without seeing it in person it's hard to advise. Not sure if it acts the same when you just rev it up from under the hood or not but on a friends you could see the EGR shaft moving a lot as you got on the gas (it should not move at all or much). His EGR failed and it was choking the engine.
 
[email protected] said:
Yea it acs the same when it's in gear or out of gear. I didn't notice much movment in the egr valve...
Click to expand...

You can temporarily block off the EGR and plug those vacuum lines to see for sure if it isn't the problem.

I am not advocating defeating the EGR, just temporary.
 
Well I brought it to work today and had one of the techs take a look at it and he dicked around with the distributor and now she is running great. Now I just need to figure out how to drop the oil pan so i can change the gasket ill be set.
 
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