Thread: Putting or sputter?

Will do. I'm going out of town for easter tomorrow I'll check out the compression on monday and see where I stand. Thanks for the advice guys.

Did a compression test today. I think I need to redo the test tomorrow though I read in the FSM that well you crank it you are suppose to hold down the gas pedal to open up the throttle. I did not but any way here are the results from this test, as you guys recall its cylinder one not making a difference when I pull the plug. Any way here we go: cyl#1 =140, cyl#2 = 150, cyl#3 = 150, cyl#4 = 130. Any opinions on this? Like I said I'll try again tomorrow holding the throttle up this time and post those but it seems #1 is decently healthly to me.

ok holding the throttle down does sometimes help, i've had cases where it dirasticly improved the numbers, an cases where it didnt matter at all..

but from what i can tell, you have compression! so thats good, chances are you have a bad injector, change it an be on your way.

i'd be really surprised to find out it was something else..

to test my theory and not spend a dime, swap injectors 1 an 2 over (think u said cyl #1 is the one not working?) , start engine, the problem should have moved from the first cylinder to the second. if so im right, go to the junk yard an grab a whole fuel rail with all 4 injectors (incase u have to do this again u will have injectors ready) and swap the problem one out for one of the new ones.

Well I tested this theory already by buying another used set off the forums in the rail still. I swapped out the whole rail. Still nothing so I thought well may be injector #1 is bad on this rail as well so I swapped #3 off the old rail with #1 off the newer rail, still nothing.
I'm starting to wonder if MAY BE the harness is bad after a certain point. I guess I need to get a volt meter and do some testing. If nothing else I might take apart my intake manifold and inspect everything around it. I really need more tools in my garage we just moved here out of some apartments and I'm slowly building up stuff.

Summary things I've tried so far:
Newer injectors in rail
all new OEM ignition parts (cap, rotor, plugs, wires)
Iacv replaced
cleaning throttle body
compression test was decent

yep check the harness

Clean your air filter. In the past I noticed more of a sucking noise when the filter was dirty. Cleaning it always helped. This will not fix your problem though.



^ This could still be an issue here...



Possible, have you tried to do a proper test (pressure/smoke) for vac leaks yet? Also, when you pulled your injectors did you change the upper and lower o-rings for some new ones? I have dealt with bad o-rings before, where I didn't use enough lube when re-installing my injectors. The damaged o-rings caused a horrible smell of fuel and something else, a bad idle and just poor running at idle. It also ran poor under throttle too. New o-rings upper/lower are $10 for all 8, from Greg V. You mentioned that the issue got worse in your second vid so maybe a damaged o-ring made the problem worse? Not sure of your timeline of actions though??



Definitely re-do the test! Make sure all the spark plugs are removed and the throttle plate all the way open. I have done compression tests with all plugs removed and also with only one plug at a time removed and noticed differences all around. Having all the plugs removed will put less strain on your starter and battery as well as making it easier to hear the compression cycles when you are trying to count them. Doing it this way changed my results too! Hot engine, ignition/ignition coil disconneted, fuel pump fuse removed, throttle full open and all spark plugs removed.

When you re-do it with the throttle fully opened you may see a greater variance between the individual cylinder readings. Right now you have a max difference of 20 psi. If that changes to 30 psi it might indicate some issues other than the current one. If it does, a leak-down test is in order as it will give you way more info then any compression test ever will.


Before all of this though, you need to grab a DMM/Volt meter and do some testing. I would check each injector for battery voltage at idle. I would also check each injector while under load to make sure each one is getting proper power. If everything checks out there and you have tried different injectors, fuel is not your issue. If you have a voltage issue there you can then check the voltage at the ECU (carefully) for the injector wires. If all is good there and not at the injector, you have a harness issue.

Have you tried switching out the distributor? It controls fuel and ignition via the rotor plate. I have had issues there before as well.

Personally, I would check a bunch of different stuff with the DMM and re-do the compression test, with a leak-down being next on the list, depending on the new compression numbers.

Beyond all of that I wonder if you could be having issues internally? Sticking valves?? Not sure....

I dealt with a lot of gremlins on my last swap so I feel your pain. Good luck, hope you find the problem.

^^^^like this Guy said, try new dizzy and check for power on the harness also check for maf voltage. Best of luck

Its a 6 month old filter that doesn't seem dirty







Have not had a proper vac test done I can't really afford to take it to a shop. When I swapped out the fuel injectors they were still in rail so I just swapped out the rail and no I did not change the o-rings but I do have a set I ordered from Greg V when I got the rest of the tune up stuff so I could try that. What do you lube them with?





Re did the test the right way this time and the results got better, they were: 140, 140, 145, 150



This is what I'm trying next I just need to get my hands on a voltmeter.



I have not I don't have an extra laying around. I just put a new cap and rotor on it though and checked to make sure the rotor was contacting all the points.




Thanks I appreciate the wisdom and your time. I'm going to get my hands on a voltmeter and do some searching. Thanks again.

I would give it a clean, you'd be surprised how dirty they get. I clean mine every 3-4 months to keep the horsepowerzzz up!




Well, if this is the case then the seals probably aren't your problem but new seals won't hurt. I used oil in the past but had issues with that. Forum member Chriscar suggested I use vaseline last year and it worked like a charm. I put a thin coating in the injector housing in the rail (metal area in the rail) all the way around, and then a decent amount rubbed onto the upper and lower o-ring itself itself. Work the injectors in slowly when putting them back in. You will be able to tell if you have enough lube on them.

When taking the injectors out u need to try and pry them out with a big blade flat-head screwdriver. Place the driver between the back of the injector and the rail (where the rail is closest to the injector) and twist the driver, they injectors should "pop" up. They can be a pain in the ass to get out. Also, be careful on the phillips screws that hold the injector caps on. They strip easy.




Numbers are a bit low but you probably have some solid miles on the engine so it's just old. Variances between the cylinders are max 10 psi, so that is good. You can stop worrying about that dead cylinder now.

Another way to tell if you have a dead cylinder is by cecking the exhaust manifold. If you have an aftermarket header you can check to see if all of the primaries are nice and hot. If one of the cylinders is not working, more then likely the corresponding primary will not be nearly as hot as the others.




Sounds like you are on the right track. Get a copy of the FSM for your car (you may already have it) and find out what the voltages should be on all of the items you are checking. Injectors, fuel pump (pump relay - if pump voltage issue), MAF, TPS, O2 sensor, IACV, etc. etc. Also, load test the battery. Might as well go over everything to eliminate possibilities.

Also, check all of your grounds and make sure they are all clean and not rusted out or weak.




Maybe somebody close to you has a spare dizzy you can temporarily try out?
Any forum members in N.C.? I would try and get a spare one, even if just to test with.




You're welcome on the time! Not sure how much wisdom I have but I do try! Also, I stalked my local hardware stores last year when I needed to buy a fresh DMM/volt meter and ended up getting one at half price! I don't pay full price for tools if I don't have to!

if its not firing only on that 1 cylinder and changing the plugs, wires, cap an rotor and injectors hasn't fixed it i'd say its gotta be the injector wiring or possibly ecu. it could possibly be the dist but i doubt it, never know though..

a fuel filter wont cause just the one cylinder not to fire, same with fuel pump ect.. how ever i could see how the injector seals might be an issue worth looking into.