Majere

5 days ago I had just filled her up with gas, then was hauling *** (55ish mph - still accelerating) to pass some cars, RPM stuck at 4k, then went to 1k, bouncing back up.. .. made it home... now she runs like this.. started to notice the missing as i pulled in. Since that i have replaced the distributor (magnet was shattered), wires (old), plugs (fouled), coil, fuel filter, fuel regulator - Ordered, cap and rotor to replace soon as I get it (looks a little worn). thinking this may be a timing issue, tps or afm? is it possible for the timing to go out? last month I had the head machine and gaskets replaced (because I noticed bubbles in the over flow). When that was done the mechanic said that the timing chain was off and had fixed it - related? Just not sure where to go from here... ideas please?

Twiggs280zx

I cant watch the video (my laptop hates me) but I would say start with what the mechanic claims to have changed, especially if it started after he "fixed" it.

Majere

it ran for weeks after the head gaskets were replaced.
just an update. so far i've replaced the chts, fuel pump, wires, plugs, distr, check for vacuum leaks, timing , etc ,etc... gonna replace the afm soon. ... looked at the ecu and saw it was re-manufactured in 2007... :/

so it runs okay when i first start it up, can hit 60mph... even though it misses at around 2500 rpms - idles well even with some missing. as it heats up though it become more and more harder to past 2000 rpms - when the temp shows it's in the middle of the gauge the car wont rev past 1500 rpms and wont go faster then maybe 10mph, it just bogs way down but doesnt stall... sometimes doing a back fire////

anyone in the orlando florida area that would be able to help?

Majere

Majere

does anyone have a good AFM and the boot that goes from the AFM to the throttle body - 1983 model for sale?

Majere

working on this issue for over a month now. (i'm no car mechanic) car is almost drivable while cold but soon as it is at operating temp it will not revv pass 1,500rpms - So I am going over timing again.... this is what i have - the red is where i found TDC but.. the car will not start with the #1 plug there - it just drains the power and wont even crank... it will run with them plugged in as seen in the picture. I don't think this is right based on my research... Can I get some pro to tell me how it is and what I need to do to get it right if it is wrong??

Majere

Guessing i am on ignore?..

anyways... think i've narrow it down to one of the following...
intake manifold leak?
injectors leaking?
timing chain?


new AFM, CHTS, AFM to Throttle body boot,

new video -
https://www.facebook.com/photo.php?v=10151883501458453

Majere

massive backfiring when car warms up, cannot get past 1,000 rpms...
Okay - so i've checked at the fuel pump and it is showing 0 with the ignition in the on position with a multimeter - Once I get her to idle I get readings of between 11.5-12.5v - Is this correct? I saw that one of my fuseable links was burnt out so I've replaced it but with no changed in the car's behaviour.
using the fsm i am unable to located where the fuel pump relay is, i've looked all up under the passenger side foot area.

replaced the middle fuseable link - was burnt out - no change in car
https://sphotos-a-mia.xx.fbcdn.net/h...28244636_n.jpg

what do these control - fsm is no help...
https://sphotos-b-mia.xx.fbcdn.net/h...85287903_n.jpg

cannot find fuel pump relay...
https://sphotos-b-mia.xx.fbcdn.net/h...57144802_n.jpg

1983 NA
https://www.facebook.com/photo.php?v=10151892828803453

NismoPick

Did you buy the gas from a cheap gas station, or top tier? I had this happen once on my 87 Toyota pickup. Ran fine... filled it up at one of those "cheaper than average" gas stations, and about 20 min later it started puttering and lost all power. I quadruple checked every single thing on the truck (SERIOUSLY), did a million tests, and finally decided to drive it super-light-footed for a few days. Filled it up again and it came right back to life. Not a single problem since.

Also, have you done a compression test?
Read the spark plug tips?
Checked / disconnected the TPS?

Majere

I bought the gas from 'wawa' - what's would be the best way to get it out? especially the injectors?

replaced th tps, nothing changed,
spark plugs are black and rich - changed them and they are black again.
just bought a compression tester kit today - will post results.

NismoPick

If it's running rich, either the AFM or CHTS is having issues. Have you ohm tested them from the ecu plug side?

Twiggs280zx

Not sure how bad your gas is but, mine sat for almost a year and after talking to another zdriver member I dropped a bottle of this http://www.summitracing.com/parts/luc-10003-1/overview/. Now , other than dead batt/alt it was running without issues from the fuel system. And yes I used the whole bottle... And filled it up. If yours is already full I think this should still work, maybe shake the hell out of the car to mix it.

mrprofile

The fuel pump relay can sometimes be hard to find, they are bolted down and often when they are replaced the people replacing them don't bother re bolting them down so they wander, I found mine floating around deep in the dash, where it wasn't supposed to be. I found it to be easier to find by keying the engine on and off because you can hear it clicking.

Majere

seems like the gas is fine, as i've just used a water treatment, and octane booster, let it ran for 30 minutes with absolutely no change.

Is it normal that the gas line after the fuel filter to be pulsing? If it isnt normal, would the fuel relay be possible fault? I still haven't located the relay - but i will check for it using the method above - thank you.

while testing today - reving high once the car is warmed up, it backfired so hard into the intake the AFM jumped and one of the vacuum lines pop'd off.

when it is cold, it doesnt backfire - it just misses a lot, especially around 2krpms

Gonna do the compression test this weekend..

do you guys think i should order a new fuel pump relay?

what are the chances it is the injectors, even though i can hear them all firing as expected?

Was thinking about getting an in line fuel pressure gauge, do you guys know of a good one to get?

alien4fish

My "guess" is its a vacuum, leak it sounds like youre sucking air into the vacuum advance possibly(but don't take my word for it) I would check ALL the Vac lines running into your intake mani etc. Pay attention especially to the Vac lines that 90' around in go into the manifold don't forget to check under the lines that you cant see from the top. Good Luck and keeps us posted, there are some of us who are lurking and reading along

mrprofile

Just FYI, vacuum lines should be soft, not hard, I bet the vacuum line that popped off was hard, and needed to be replaced. Also while you are looking for a vacuum leak think about this stuff, a vacuum leak will not always be on the intake manifold, the brakes have a vacuum line from the intake, the cruise control does, the climate controls do (that's what the hissing noise is when you switch vent settings), etc... and any one of those things could be leaking vacuum. now it doesn't mean you tear apart the dash and go looking around for a leak, no you stop it at the source, remove the vacuum hose and plug it at the intake manifold and that will cut off the entire circuit, if your idle doesn't change then that vacuum circuit isn't the problem and you should move on.

Majere

think i finally pin pointed the cause of this issue...
with the car idling...
i sprayed some starter fluid right where the intake manifold meets the head...
well the RPMs raised....
so is it safe to say that i have a leak at the gasket there?

mrprofile

Possibly, but dont tear it apart yet, the fluid could just be sucked in through a vacuum hose still. Do a smoke test, go to youtube, and search scotty kilmer smoke test, that video will show you how to do it.

WildmaN

How about also checking the intake and exhaust manifold bolts? Make sure they are pretty snug. Maybe they need to be tightened because of the gasket adhering more to the surface. Just a thought, never hurts to check the easy things. Good luck man.

mrprofile

just don't over tighten them, tightening more then torque spec can be just as bad as tightening below torque spec

Majere

okay so 3 months down the road now and still no resolution. I've taken her back to the mechanic who did my head gasket, he is claiming that the new distributor replacement i bought is at fault. that is absolutely not a vacuum issue... I got this new dizzy from rockauto as it was my first idea of what my issue was and replaced it right away when the car started acting like this, but since I didnt see a change in the car behaviour i moved to other parts. He says it is the ignition control module specifically... but I wonder??.. because he also states I should find and replace the whole dizzy again, but with an exact OEM and not another aftermarket 'CARDONE reman'. dizzy that currently in there.

What should I do?

Majere

solved - Ignition Control Module.

The replacement distributor from rockauto was bad - so when i had replaced it (first thing i replaced) it wasn't fixed. i bought a new ICM from ebay and now she's purring as expected.

Thanks for all the above advice. I hope my post will help others.