Another crank/no-start.

[supra90mkiii]

Alright, so I recently got my car running after my winter project. sp61gtbb, maftpro s/d, plugs bkr7e 0.28, wires msd 8.5, new i/c piping, rebuilt tranny. It had been running fine for a couple days. I took it up to school yesterday, 50miles, and the trip was fine. Even on the way back, the car was still running good. But I did notice that it was running rich under part throttle. Anyways, I stopped at a firestone tire dealer to pick up the tires I had ordered, and when I got back in my car to start it... It cranked but didn't start.
Also while cranking it sounds like it stops cranking, almost like a backfire?

So after sitting there and thinking for a while, I come to the conclusion that maybe it's flooded, or the plugs are already full of deposits from running rich during that trip. So this morning I went and installed some autolite 3923s. But they did not help. But I also noticed that after the car has sat for a little while, It will crank longer before "backfiring". And, if I pull the EFI fuse and crank it, it will crank all day long, and sound normal (not like it has no compression).

I have not seen boost with this turbo yet, so it's not like I was driving it hard. And when I got to the firestone, It shut off just like normal, no wierd sounds.

I miss my supra! two days of driving doesn't make up for 6months of downtime over winter.

Any suggestions would be wonder full. I think the next time I go, I'll somehow disconnect the fuel pump, and crank it with just ignition, and hook a timing light up to it. and maybe before that i'll wiggle the cps wires, although I haven't had any problems with that, and the cps was not removed this winter...

ugh idk... I need a break.

 

[supraguy@aol]

Honestly, it sounds like the timing is waay off, and that with the EFI fuse in, it's creatin cumbustion that works against the engine's normal rotation, and that would explain why it cranks easier without the EFI fuse in. As for how this happened, I only have one possible explanation: The CPS is loose. This would also explain why it was running way rich, as its firing the plugs at the wrong time, and not able to burn all of the mixture. Check to make sure that it is postitioned properly, and that the adjusment bolt it tight. HTH

 

[tte]

Yeah...adjust your cps

Cheers,
Roy

 

[pimptrizkit]

did you just install the maft pro?

what supraguy said makes sense,

unless your timming is spot on,

you said you didn't adjust or remove it,

and so long as the bolt stayed tight the cps wont be off as far as the cam goes,
but is the cam timming correct?

when i first read you post what had came to my mind is you have not satified vf, and you either have added fuel on the map, or the map was wrong an the car is finaly given up fighting on pulling enough full out to get it to run right

when starting it, try blurping your gas pedle,

if it is flooded, from to much fuel sprayin, or a leakin injector, you will get it to fire off,

also , if you hold your foot to the floor, and crank, it will cut the injectors, this is called clear flood mode, or some where along that,, still sparks but shuts off the injectors untill an signal from igt/igf is recived.

i have a similar problem, mine from what i under stand is from being to rich at idle, im running around 12's at times but driving im running 14's15's,
if i leave my car idling long enough, it will raise back upto mid 14's after a few minutes of idlin,

i thought i had a bad cold start injector, pulled it and it sprayed a good mist,
i dont have a cel light on, so nothin to major is wrong,

but as i pulled fuel on my map tring to get the overall map correct i found that less fuel at start up the better my car seemd to start,
ie i was floodin it,

 

[supra90mkiii]

The cps bolt is tight, and looks like it is still in the same position as last week. When I first got it started last week, I did recheck timing, and it was at 12 deg advance without the diagnostic terminals jumped, like it's supposed to.

and I haven't adjusted any fuel trims with the maftpro. I am getting fuel pressure, so it has to be an ignition/timing issue.

Thanks for the suggestions guys. i'll try messing with it some more.

and I wasn't sure if our cars had the clear flood mode like you described, I remember GM vehicles do that, but wasn't sure about ours. thanks.

 

[pimptrizkit]

i just set timming an a stocker,


the timming should be 10+ btdc, i usualy set mine at 11/12 like you said,
thats with the test connector jumped,

the ecu adjust's timming as needed, and the only way to correctly set it is with the t/e1 jumped in the diag box, other wise base timming will go out the window..

do check to see if the exhaust cam has jumped a tooth on the timming belt,

i almost bet this is your problem but eh..

 

[supra90mkiii]

well i got her running, and drove home. all i did was mess with the wires for the cps and tap on the plastic cover. (hitting electronic things always fixes them) I did notice that my cps cover has a few cracks in it around the screws. Should I replace the whole cps? or just the cover? Also, timing belt was replaced by me personally about a year ago. and if you look in the tsrm, base timing with the test terminals jumped is supposed to be 10btdc, and when you unjump the terminals, it is supposed to goto 12btdc. I didn't adjust it to 12, i just double checked that it was still there from the last time i had to adjust it (over a year ago). hopefully that cleared up any confusion, and thank you guys for all the help!

My idle seems very erratic right now, but it eventually smooths out. I think that is because the ecu is in it's "learn" mode, since i had the efi fuse disconnected for a little while.

 

[pimptrizkit]

whats your vf doing when your engine is hot and idling erratic?

 

[bigaaron]

The green 4 pin connector is a very common spot to have a problem. There is so much heat there coming out from under the exhaust manifold heat shield that is cooks the cps wiring. Sometimes replacing the cps is the best way to go, but it's an expensive part. Some places sell them remanufactured, which will save you a lot of money.