Backfiring- No power- generally bad running-SOS

[HackofDestruct]

So here's the story. I picked up a 92 Plymouth Laser RS AWD for 1100 it needed a head. The car has 94k good body, mint interior and is in pretty good condition. So I put a head on it and got it running a 16g. The car came with a Walbro 255 but no AFPR. the car does have a MBC and has the taboo vacuum setup. So the problem is. there is a vacuum leak that you can hear that sounds like its next to the throttle body. So we rebuilt the throttle body with new o-rings. Didn't fix it. So then I went to the injector seals. didn't fix it. So mean time while I am messing around with the stuff. The car runs very badly. The timing is all correct. Did it with a timing light. The car idles at about 1k back fires when you push on the gas in any gear and has absolutely no power hardly enough to move itself down the road(well it moves down the road but not very well) the boost is set at 7 PSI and once you get above 4k the backfiring stops and it runs fine but still no power. Also the boost gauge shows about 17 vacuum so I don't know. This is my first DSM but I've worked on lots and lots of cars doing this stuff but this one is kicking my butt. I need some help I'm feeling very defeated.


Any words of inspiration would be good to hear.


Thanks-
Alex

PS the ecu looks perfect so its not that. I have also searched up and down the forum for about 2 weeks in my off time between the car and bed so I need help bad

 

[alex99gst]

You don't think it could be possible that you are running very rich and that is why its backfiring and being very slow? I assume your gas mileage sucks as well. Maybe just as a test try to borrow an AFPR from one of your friends and set the pressure and see if that changes anything. It's a start, or you could go ahead and spend the money on one if you were going to buy one to begin with.

 

[AlumRodLaser]

Check for boost leaks. Make sure you have the cam timing correct, since you just swapped the head that looks like the most likely source of your problems.

 

[alex99gst]

Check for boost leaks. Make sure you have the cam timing correct, since you just swapped the head that looks like the most likely source of your problems.

I believe he did.

The timing is all correct. Did it with a timing light.

 

[gurmanator]

backfire=timming or ignition.sounds like your base timming is of.what happens in a backfire is the intake valve and exhaust valve are open at the same time which causes low compression which = no power.sounds like you are 180 degrees off on cam timming.a timming light will still show the marks are ok(false readings).

 

[HackofDestruct]

So how do I correct the timing?

I was going to get an AFPR as soon as possible and it was on my list but I should still be able to get some decent get up and go out of it.

I am going to check the MAF and coil pack today and hope something works.

Any help on the timing would be great these DSMs are all new to me. Cars aren't new to me at all though. So you can be as straightforward as you want.


Thanks-
Alex

 

[91talonawdtsi]

did you ever find out whats wrong mines doing the same thing

 

[HackofDestruct]

No I haven't figured it out yet

We pulled the plugs and they were pretty sooty so I'm ordering an AFPR this weekend and hopefully get it all tuned. We are going to take off the lower timing belt cover to check all the timing marks and make sure nothing skipped a tooth. Hopefully it didn't because that would SUCK. On monday however we are getting the car scanned for the check engine code. Hopefully they come up with something and can give me another clue. I am also going to swap out the coil packs for a known set of working. Again hopefully that yields something.

Once again the offer goes out if you have any advice please tell.


Thanks-
Alex

 

[91talonawdtsi]

Check the injectors i just got mine fixed and i had an injector that was hanging up.

 

[ECLIPSEESPILCE]

Those camshaft marks can be tricky be sure that they are properly aligned. A compression test may help with this. Ignition timing is different than valve timing.

 

[HackofDestruct]

yea I know I'm going to do a compression test on it this week and see what I'm at.
Its harder that all hell to turn over by hand so I'm assuming its good but we'll have to see.
I'll keep everyone post on what happens. Right now though I'm in search of a CHEAP AFPR
and I mean cheap. Any ideas on where to find one?

Thanks-
Alex

 

[qtxdevilz]

sounds like a problem with your timing...when you did the head did you make sure all your marks were lined up...

also do you have a logger...that will tell you alot of what is going on under the hood...

 

[kelvinb]

an easy way to see if you are running rich, is put your hand over the exhaust, or let it idle for alittle bit and see if the ground has turned black . afpr isnt really required, but highly reccomended if you want it to run right. good luck