1990 vert S5 TII

well compression is perfect and only on like 20k miles on the engine, spark plugs are new and wires are new, rpms work so I know trailing coil is firing, and a timing gun flashing when hooked to either leading wire shows spark outta the leading coil, the car does smell very rich, but also has no cats or anything just two mufflers. Now I have noticed on the starting procedure to getting it started is it takes about 15-20 2-4 second cranks and each one gradually starts better and runs a little longer until it fires up. And then it runs fine once started. it does have a smooth idle if i set it around 750-900rpms but never stays running for than a couple min, but as soon as I set it above 1000-1100 it idles and climbs up to about 1500rpms then drops to 1000-1100 then climbs does that over and over.

 

when you adjusted the idle speed you moved the throttle stop and failed to calibrate the TPS,, this is why it surges

had one of these the other day with gilmer drive attached,,
once started it was fine,, but pinged immediately as it went to boost,, despite timing and fuel changes

when re-installing the mazda pulley it was obviously 180 out
,, and so t1 and t2 fired back to front,, timing was out and the car constantly ate plugs



make sure your wires are around the right way
and be sure the timing is correct

 

so you have to calibrate TPS everytime you adjust the idle speed? TPS = 1ohm - of 3.5ohms +-1ohm at WOT right? and to be honest Ive never timed a rx7 or even seen it done so ill look into that next and make sure everything is good there.

 

so it smells like monster gas around the car so i am leaning towards flooding, cause I can turn the FP off and the gas smell goes away then i will turn it on and it will want to start then nothing and after a few attempts at starting it will smell like gas really bad

 

Leaking injectors?

 

When was the last time the engine was worked on? Bad Vac leak? Are you sure vacuum lines are correct?

Have you done a compression test? You could be running on one rotor. If everythign is right, that would explain the monster gas smell.

 

make sure the MAF and the Fugging Hose on the tube is plugged in. that will get ya every time

 

Engine was rebuilt and ported like 20k miles ago and compression test was perfect, and most vacuum lines are removed but yea everything is plugged and good. I'll check the maf and the hose but I dunno how I would have missed that one

 

Do you still have the IAC? Is the hose from the IAC to the intake plenum still on tight? Also when was the last compression test?

 

Engine: dead

So 4 days ago and about 2 miles of driving from then, it went from good compression 80-85 front and back to 0 compression rear and 65-70 front? o.O

 

Flooded. When you flood an engine it will make compression test results not accurate...raw fuel in the chambers = no compression.

 

Pull the plugs out and let it sit, Maybe put some oil in it after a while.

Unfortunately I think it's toast though. The reason I suggested the compression test is because I had the same thing when the engine in my GTUs was toast. It would run and idle for a little bit, but it stunk like gas and back fired a whole lot.

Rebuild it!

 

I had that and it turned to be a loose wire to the injector.
Let it sit, pull the egi fuse, pull all plugs, crank to get excess fuel out, add oil in the spark plug holes, crank some more, put FRESH plugs back in and try and fire it up.

 

how will raw fuel show zero compression? and ill give it another shot tomorrow and see what happens.

 

results depend on the crank speed,, which plug your measuring from ,, the restriction through the check valve and if you have WOT while cranking
did you check the comp,, or did a pro do it?
did you test with a different gauge than before?
does the 0 rotor woosh hard with plugs out cranking?

if the tps is out,, it will flood worse on cranking,, and if it does start, it will not idle long
a bad or dying battery will compound the issue on cranking,, and overload the engine with the alt when it tries to idle

check battery voltage is 12.5 ish volts and more with engine off
anything less indicates the alt will be working hard at idle

calibrate the TPS with engine warmed up,, but turned off ,, and shoot for less than 1k ohm between green/red and black /red

then try a tug start ( 2nd gear, 30 kmh with ignition on, let the clutch out )

 

Top spark plug for compression check, not WOT. rear rotor does "woosh"But I dunno the difference between a good and bad one, and also I did do a pull start and it fired right up. And also it pulls pretty good and doesn't feel like its not running on the rear rotor.

 

cool,, sounds like you had a dud test
( you need the throttle wide open when testing )
and sounds like you have a flood issue

also if that alt is hard charging then it may just be a matter of setting a faster idle and calibrating the tps to that new position

turbo cars sometimes have a bypass adjust screw on the BACv and so dont need to fiddle the tps calibration all the time

dont forget to fit yourself a fuel pump kill switch while you go about sorting that tps calibration

 

Alright well I'll give it another shot, and for the idle and TPS setting, I have the throttle mod done so I heard I dont need to set it warm, but what exactly do I do? Get it running if I can, then pick my idle possibly a little high then turn if off and then set the TPS?

 

the FSM tells you not to adjust the throttle stop screw, but if you do, since it changes the position of the throttle blades, then yes you do have to adjust the TPS.

or think about it this way, when you adjust the TPS you are telling the ECU that this is where the throttle is closed. if you move the throttle plates, then the ecu will just see that as opening them, until you reset the TPS to zero.

i like to set the TPS with the factory 2 light method, as its the OUTPUT from the ecu, the 1 OHM method seems to work too, but it doesn't take into account the resistance in the harness.

ive also seen that a flooded engine will compression test poorly. we did one at the dealership it came in testing in the 5's and running on 1 rotor. once we replaced the coils (it was an Rx8) and ran it with ignition for a while, the compression was back up to 8's. if i didn't see it, i wouldn't believe it.

so i'd reset the TPS, crank the engine with no fuel (pump) to clear the flood, clean the plugs and try again. you could put a little oil in the plug holes, it will help compression, but i personally don't like the smoke.