RyoFC3S

iTrader: (1)

Hey guys,

I usually don't post up on here unless I absolutely can't find my problem from searching, or if I'm completely stumped and can't figure out what to do next...

I thank you in advance for reading this long post, but most of this is necceary to get the full scope of the problem. I try to give as much information as possible to help the more experianced members diagnose the problem.

The car: 1990 TII, moderately/heavily modified. Mods are linked in my Signature. Right now I am running an SAFC II for fuel control. Besides upgraded injectors, fuel pump, FCD, and AFC, the fuel system is completely stock. I replaced the TPS less than 10,000 miles ago (maybe even less than 5000), with a used one that tested fine and was adjusted exactly to spec.

The problem:

First off, a few weeks back I noticed I starting having hot start problems. It started suddenly and out of the blue, and got worse and worse. After I would run the car until it got to normal operating temps then turned it off, It would not start again. It smelled flooded, and I think I would make it worse and worse the longer I cranked it.

Here's an idea of how bad it was flooding: I have an exhaust leak between my exhaust manifold and engine (the manifold is warped where it bolts to the engine), and it was so badly flooded that fuel was dripping onto the ground through the crack, and after 5 mins of cranking the pool would be about as big as a basketball.

At first, if I held my foot to the floor while cranking (to clear the flood) it would start after about 2 or 3 minutes of cranking (and would run normal). After a while though, that didn't work anymore and it absolutely would not start until it had cooled down almost completely.

Also, I started noticing a few weeks back that my AFC settings didn't seem to be correct anymore. It was running rich. I would notice under WOT pulls it would choke on the gas and fall on its face; stopping acceleration. In some areas, I would lean out the AFC nearly 10% from the settings that used to be perfect (dyno-tuned!). I did not notice a significant gas mileage drop (probably because I was constantly re-tuning the AFC).

So I finally called my mechanic and asked his advice. He thought it sounded like one of my injectors was sticking open, which I thought made sense, so I took the engine apart and tested the injectors. Under cranking, with the FP unplugged, both primary injectors seem to fire normally (the pin moves in and out periodically), and neither of the secondary injectors fire. So I took all 4 injectors out and gave them to my mechanic to test them. The results came back, all 4 were easily within spec. These injectors all have less than 10,000 miles on them, and were bought brand new.

So I put the engine back together today, and now it won't cold start. As far as I remember, the TPS was fine before I tore the engine down to check my injecftors. It tries to start, but it gets to about 500rpm and just kind of glug-glug-glug-glug's, but won't start. I have successfully gotten it to crank up to about 800-900 rpm while holding the starter, but once I let go of the starter or hit the gas it just dies.

The TPS signal on the AFC is very odd. It reads roughly 42-45% when my foot is completely off the gas, and the number is constantly moving (not much, less than .5%). When I push it to WOT, it reads somewhere between 95% and 100%, but changes almost every time I floor it.

Under cranking, the TPS signal is very strange. When my foot is off the gas, the TPS signal jumps all over the place between 0% and about 40%, giving me random numbers like 2.4%, 27.9%, 35.0%, 0%, and everything in between. If i'm at WOT while cranking, the same thing happens, but the range is about 85%-100%, and everything inbetween.

It also smokes under cranking (after a few minutes), but does not smell nearly as strong of gas like it did before. The color of the smoke is bluish-white.

Honestly, I don't know if I fixed the fuel problem/hot start problem I had before. I'm pretty frustrated with this thing.

Thanks a ton for any help you can offer me. I'll check back here often to answer any questions you guys have or to read suggestions.

HAILERS

When the engine is cold, the tps should read higher than zero, because the water thermowax should be holding the throttle open a touch. Designed that way. Once hot the thermowax extends and the throttle plates close all the way and the tps reads zero. (I think it's zero on a SAFC and 20* on a RTEK2.0).

The ECU has a ATP, atmospheric pressure sensor that should compensate for altitude changes for fuel delivery.

If your having sudden cold start problems, go look and see if the water thermo sensor plug got put back on or if the signal is getting to the ECU.

During START the ECU does not use the afm but uses a START MAP internal to the ECU for fuel delivery during start. Once over 500 rpm the afm takes over fuel delivery. That information might/might not help.

HAILERS

The fuel dripping out the exaust probably meant a fuel injector was leaking pretty bad.

RyoFC3S

iTrader: (1)

The water thermo sensor plug is the electrical connector on the back of the water pump, right? If so, yes, its still connected.

Also, I seem to remember that in the past the AFC did read 0% throttle until I actually put my foot on the throttle...

Anyone else have any thoughts? Thanks HAILERS....