Dead in the water

[Sunbeam2]

93 Sentra, 1.6 Still misfires
We have changed all the injectors, the fuel Filter, plugs, dist cap and rotor.
and the plug wires and it is still misfiring. what to do now?????

[91STT]

Which cylinder? Have you done a compression test?

[Sunbeam2]

Just got a new compresion tester this morning, the old one gave me all kinds of diff readings every time I used it

What speciafically should I do and look for so I get this test right

[Sunbeam2]

I should have added this

Drove the car and at idle and low speed is misfires and shakes like mad but as I speed up it appears to smooth out????? Slow down and it shakes again

[91STT]

When doing a compression test, there is no set value you are looking for; only that they are consistent across all of the cylinders. A 10% deviation among cylinders is generally acceptable.

[RaeRae1]

Has anyone thought about looking into the MAF? Are you getting an engine code of any kind?

[Sunbeam2]

There is no engine check light.

I was thinking about checking for spark using a timing light on number 4 wire, if it flashes that would tell me if there is spark, I think????

When doing a compression check, should I do it on a cold or warm motor????

[Chiquae07]

Originally Posted by Sunbeam2

There is no engine check light.

I was thinking about checking for spark using a timing light on number 4 wire, if it flashes that would tell me if there is spark, I think????

When doing a compression check, should I do it on a cold or warm motor????

check your MAF. start the car with it unplugged and see if it runs better. if so, then there is your culprit.

otherwise you pretty much replaced everything.

i know that when my MAF was going out, that it was sluggish until i got moving, and replacing the maf fixed my problems.

[Sunbeam2]

what is the maf and where is it located???

[Sunbeam2]

First we put a timing light on each plug wire, they are all getting fire.

Pulled all plugs, cylinder 1 and 2 got 90psi first burst and built up to 155 psi
number 3 initially got 90 and built up to 120
number 4 got 60 and built up to 120
went back and rechecked number 3 and now it read 60 and build up to 120

As engine was running we pulled the plug wires one at a time and it appears to be running on number 1 and 2 only

I unplugged the maf and then plugged it back in and the engine ran a little faster when unplugged and when back in it then slowed again to where it was

What is wrong

[slideways...]

blown hg? 120 is low on the compression test...155 is a bit low too but not horrible. get your valves/head checked too you may have bent valves or something.