94 FD Hard to start
 

So up until yesterday my 94 FD ran perfectly, but today I went to start it and it cranks, catches and then dies immediately. If I do this more than once or twice it wont even catch anymore just crank, I assume due to flooding. I have deflooded and was able to get it started and running normal once by giving it gas while cranking and then rev it up past all the poping an backfires, but after I shut it down 30 mins later it did the same thing all over. Once I get it started it will run and drive totally normal until the next time I try and start it. Ive checked for loose connections, vacuum leaks in all the obvious areas, checked fuses, swapped plugs when I deflooded the first time. If I let it sit for a while and then give it gas while cranking I can get it to start if I rev the shit out of it lol But the problem starts all over every time I shut it down.

What could this be? Ive spent hours and hours scouring the web and trying every suggestion, but to no avail. Any suggestions would be much appreciated.

First Check for codes.
Second guess is map-3rd is tps.
and the 4th is-------:wtf:

Check compression , smae issues with a low compression motor =(

Compression checks out, I'm begining to think it's a fuel related issue...could it perhaps be a malfunctioning fuel pump? When i turn the ignition "On" without trying to start it I hear a faint thump noise from the rear that lasts like a quarter of a second and that's it. Shouldn't there be an electrical humming noise?

, No the fuel pump will prime the system then shut off until you crank it then the fuel pump will turn on again .

do you have fuel in the tank ? when was the last time you changed the fuel filter?

"Compression checks out, I'm begining to think it's a fuel related issue".

Bingo.... You are a winner!!!

Sent from my iPhone using RX7Club

Plently of fresh fuel in the tank, over half a tank. Haven't changed the filter in......ever.....lol I heard it's a real pain in the ass...sigh....guess I know what I'm doing this weekend lol Hopefully that does the trick, I want muh baby back on the road lol

Check the plugs see if its flooded or if its dry , and you will see if your fuel pump is bad , or maybe your plugs are just old .

friend of mine had a similar issue car was starting , then stopped changed plugs and fired right up .

First thing I tried was new plugs and deflood procedure while they were out.

Would the plugs themselves be wet if it's flooded? And if after trying to start it a lot of times the plugs are dry that means it's not getting fuel?

So I pulled the plugs and the trailing plugs were indeed wet. After cleaning and drying them out the car started right up but would not idle or stay running unless I gave it gas, nonstop popping and sputtering and won't rev past 3k. Before when I finally got the car runnning it would run normal......sigh

did you place the plug wires correctly ? are you getting any code ?

Yes, plug wires are correct. No codes, no CEL....nothing.

seems like you're getting fuel either hte plugs are bad , or you are missing spark . bad plugs , bad wires , or maybe bad coilpacks . if you have a spark checker tool , give each wire a try and see if its got a strong spark , have you loosened any grounds recently ?

Don't have a spark checker tool :( Gone through 2 sets of plugs now, guess I'll try plug wires next. Do you have to take the manifold off to get the wires off and on the coils?

So my buddy helped me do a spark test by having me hold the plug wires a quarter of an inch away from the plugs while he turned it over and 2 of the plugs, 1 leading and 1 trailing didn't have any arc. So hopefully it's the wires and not the coils lol

It's funny how people that can troubleshoot their own problems in their cars are here giving advice every day to other people.

If you have a bad coils try swapping the trailing coils to see if you get spark, if it doesn't change by doing that it might be the igniter.

So, I replaced the coils, spark plugs and wires, and the fuel filter. I cracked open the fuel line going to the rail and it has pressure so I know the pump is working. Still having the same issue, will turn over and start the first time prior to flooding but will pop and backfire like hell until i let off the gas at which point it dies, meanwhile the rpms won't go above 3k. Then it will just start for half and second and die from there on out with no response to throttle until I deflood it or let it sit a while. Don't know what to try next....there aren't any mobile Rx7 repair specialists in my area as far as I can tell.

Any suggestions would be greatly appreciated.

Take a trip to home depo and get everything u need to make a home made fuel pressure gauge and test the fuel system out. These car are 20 years old. My fuel pump went out two month ago and I thought it was a coil issue. Test it with a fuel pressure gauge while following the service manual.

you could have a leaking injector that is drowning out spark. May be getting stuck open because of some debris and flooding the Motor

How would I go about testing this?

It wasn't TOOO difficult ,

I had to do this to my car recently ,

First you remove the TB , the upper intake manifold , expose the rats nest .

Loosen the coil packs , then loosen the bolts of the rats nest

I have simplified rats nest so things were a bit easier for me , You loosen the 3 hoses that go form the rats nest to the lower intake.

you need to loosen all the hoses that connect to the rats nest as you will need to lift hte rats nest a bit , and the ACV it is 3 10 MM bolts . its pretty self explanitory .

after you have everything loose . ( you dont need to remove it compeltely just give you enough room to work with . )

You have the fuel rails . Loosen them they are held on by 2 12mm bolts each rail , the secondary is easier to get to so I'd start with that one , loosen them then the lower ones are the primaries . you dont want to loosen them completely , because after you have them loose and you have enough leverage

you will want to jump the fuel pump . and then check each injector for leaks

I found one of my injectors had a leak . so from there you can send them to be cleaned and flow tested .

Oh one thing be careful nothing falls into the engine while you are doing this

and careful with the injector grommet / orings

So I went ahead and replaced the fuel pump as well now after seeking advice from a local mechanic and still having this issue. I took video of how the car runs when I am able to get it started and posted it on youtube. Here is the link, any advice would be grealy appreciated.

Rx7 Won't Idle, Smokes and Runs Choppy - YouTube

change out your primary injectors

Pulled the primaries, they looked visibly fine but replaced them anyway. No difference in the way it's running :(