alk687

Hey guys. I just swaped in a motor that I bought. Its seems as though everything is installed and plugged in perfectly fine. The engine cranks but will not turn over. It turned over for a few moments with starter fluid, but then dies out. So it is getting air and spark so I believe I have a fuel problem. The fuel lines going to the engine itself are fine. We checked them out and fuel came out of them, kinda messy, lol. The engine was running before I bought it too, but sat for a while. Could it be it just needs to be cranked over for a while to get it going? Sorry as I am new to this all. I thank everyone for their help ahead of time. Dieing to get this thing running. First FC and been waiting 6 years to drive one, lol. Still yet to be driven. Poor FC.

greener_dude

chances are if you use the search button you can narrow down your problem to something more specific. that way people can help you better.

Killert2

maybe injectors arent opening. cheack all fuses

farberio

iTrader: (7)

If it was sitting for a time you could have stuck seals. Try putting some motor oil in the leading(I think leading) plugs to help build compression.

alk687

its seems that it is definetly the injectors. they dont seem to be working. but im not sure if its the injectors themselves that are bad, or some kind of electrical problem. I have spent a bunch of time searching the forum but not to much avail. does anyone have any advice? i know it must be the injectors not working because we had a small leakage at the injector, but when we took the injectors out, they werent functioning.

CliffIV

I don't know if it makes a difference or not, but the engine is an 88 and the car is an 86. Are the computers compatible? I wouldn't see why not but I read that is has different fuel injectors, though they plugged right in so I don't really know.

I'm going to try and find some noid lights to see if the fuel injectors are indeed firing.

The previous owner of the car turned the wiring into a hellish rats nest, which doesn't make anything easy.

Davidov

iTrader: (2)

I know some people on here might not approve of this method...
When I had a fresh rebuild(complete), I had it installed within a matter of days, quadruple checked the wiring and fuel lines, and still was getting slow cranking even with a battery charger attached.
I used ATF, a small amount, and for some reason that allowed the engine to spin over fast enough to build compression and fire up.

alk687

any ideas guys? anyone have a similar problem when they swapped something like a 88 na into a 86 na?

farberio

iTrader: (7)

An 88 and an 86 are the same computers.

Try
or



And report back.

RX7Tuner.

Cars run on 3 things: Compression, Fuel, and Spark. Spend $30 and buy a compression tester. This tool will be valuble the rest of your life. Pull an injector off and apply 12v from the battery and see if the pin at the tip clicks. You can test it further by running fuel through it. Pull out a spark plug and reattach the wire. Ground the plug tip to the block and turn the engine over. Look for spark. These tests will give you a better idea of where the problem is. If everything checks out, we can do more tests to narrow it down. Let us know.

Brian

CliffIV

We're getting compression and spark. The engine runs quite smoothly and beautifully on starting fluid, but as soon as I take my finger off the nozzle the engine cuts out.

It basically fires right up and runs (so smoothly too) on ether. Really looking towards a fuel issue. I'm waiting for alk to come back so we can mess with it more, but we'll be sure to test the injectors,and we'll throw the compression tester on for ***** and giggles.

misterstyx69

iTrader: (142)

Check the Fuel Lines at the engine.Make sure that the Primary Rail is the first to get Fuel.If it isn't then the Car won't start.This may explain why it fires when you Put Starting fluid into it...You can always try another thing,which is Swapping the wiring on the injectors..that will tell you that the Fuel is being delivered Backwards anyhow..I hope that is As simple as whet I just said..POST with results..a Newly Started swap is like a newborn..you never forget the first sounds of it!

alk687

Well we checked everything. Injectors are getting fuel and they are working. We used a stethescope and can confirm they are going click click click. The either fuel pressure regulator or the pulse valve thingee on the primary fuel rail looked like fried **** so we replaced it with the one off the old engine. Swapped the wires in case they were backwards and still nothing. Spark is confirmed, compression is fine, and it's getting tonnes of air. The only problem seems to be that it's not getting any fuel. It runs right up on ether and it's not a problem, just won't live on it's own will.

One other strange thing, when we crank it, it will run on ether, until you let go of the key, then it turns off right away. The ignition wiring looks pretty straight and actually looks to have been replaced, but the thing that we keep coming back to is the fact that the old motor started right up even with half a rotor and none of the other one.

All of the wiring looks fine and we pulled the huge rats-nest out, all the wires are stock now.

Any ideas? We checked and everything is working. Injectors, pump, ignition coils, plugs, wires are diesel high performance MSD wires.

We're pretty much stumped over here, any ideas anyone has would be greatly appreciated.
Thanks lol

wtdpn115

try holding the flapper in on the maf.. see if it will run while u push it in..
maybe vac. leak?
i kinda skimmed though what people wrote but yeah try that see if it will run
and if it does run um check for leaks

RX7Tuner.

I would check the timing. When you say it runs until you let the key go, are you saying the starter is keeping the engine's rotation? If so, I would say it is not running from ether at all. Sounds like it's catching but not running. Might still be a fuel issue. Is the ecu known to be working?

Enthu

iTrader: (1)

To the OP, did you use new Gaskts on the UIM and LIM? When I put my engine in I had a similar problem and checked everything. I was ready to give up when in an unrelated search I was lead to discover the UIM gaskets MUST be replaced in nearly all cases for engine swaps!

If you have a vacuum leak at the UIM your engine will behave as you describe. So go and get new gaskets for the UIM to LIM and see if that fixes the issue. Chances are it's some kind of vacuum leak.

CliffIV

It seems like it's some kind of vacuum leak. We pushed the flapper on the vane air flow in and cranked it up and it actually ran by itself for a bit. Nice and smooth, smoked for a bit then cleared up. But it keeps on dying if you take the screwdriver out of the VAF meter.

The gaskets are fine.

RX7Tuner it catches and runs, we let go of the key and it actually stays running now but only with the VAF pushed in.

I checked and rechecked every damn vacuum line, they all go somewhere, and being old as hell they all are bent to pretty much where they go to.

May have to bust out the vacuum pump now and some vacuum diagrams.


As far as we know the computer and everything is good. The old engine, even in its horrid state of disrepair, cranked and fired right up, and ran.

micah

Are you sure you got the fuel supply and return hoses hooked up properly? Might be backwards..

CliffIV

We checked this about 10 times before moving on to other things. As far as I can tell, they are on properly. Do you know which one is which? Can't seem to find in any manual.

micah

FSM has it... for sure. Check rotorwiki (in my sig) for these manuals..

Specifically: http://www.rotorwiki.com/index.php/S...cal_Schematics

Have you tried just swapping them for giggles? If you couldn't figure out which is which... I would have atleast tried them backwards for fun. hehe.

Anyways, enjoy,
Micah

CliffIV

She's straight with the fuel lines.

CliffIV

...or not. We swapped them over and ta-dah she fired up and ran on her own will. Still have some kinks to work out but I can't believe it was the ******* fuel lines after all this. I must have switched them 8 times in the beginning before ruling them out, then dicking with everything else fixed the original problem, but the lines were swapped. How simple.

Now to hammer the kinks out and get this baby humming.

RX7Tuner.

Good to hear

Davidov

iTrader: (2)

Hah, I know the feeling. You want to kick yourself in the head, but you're happy that is was a simple problem and not something major.

MidnightOwl

Wait, is the OP still having the same problem? I think someone hijacked the thread. Anyway, I had this issue when I first swapped my motor, and it turned out that I didn't plug in the resistor pack for the motor. Woke up the next morning, plugged it in and it fired up on the first try.