Engine dies for 1/2 second and backfires

W

Wes

Donating Member
Having a problem here with my friend Bill's Ty, it is running great - it feels very strong, but under full throttle it will occasionally die for a moment and it seems to get a small backfire. Then it comes back to life.

I'm thinking maybe the ignition is shutting off for some reason? Maybe a bad coil or something, but not really sure. It doesn't have a fuel pressure gage but I'm assuming with the backfire it isn't losing fuel. Ultimate chip is set to medium/rich fuel.
 
myclone

myclone

Donating Member
Fuel pressure needs to be checked if its happening at WOT. Lean backfires happen so make sure fuel pressure is rising at a 1:1 ratio and holding steady. If its not FP then my guess is ignition probs.
 
sytyguy

sytyguy

Moderated User
Wes said:
Not overboost, it has an Ultimate Chip. It's running at a solid 15psi.
Click to expand...

You didn't say what setting or version Ultimate you had.........and since a lot of the Ultimate cals have a MAP based fuel shutoff (i.e. Overboost - see 0x03A3 & 0x03A4), I figured it might be worth mentioning. But, if you say it's not, then it's not..........

Otherwise, like Dave said.

Hood
 
nick041881

nick041881

Member
detonation? did it just start doing this? are you sure that you didnt get a bad tank of gas? whats the knock look like with datamaster?
 
W

Wes

Donating Member
Unfortunately it has no fuel pressure gage, he reset base pressure for emmissions but I'll recheck it when I can.

myclone said:
Fuel pressure needs to be checked if its happening at WOT. Lean backfires happen so make sure fuel pressure is rising at a 1:1 ratio and holding steady. If its not FP then my guess is ignition probs.
Click to expand...
 
W

Wes

Donating Member
It's a fairly recent burn, 50psi injectors. It does feel similar to overboost but doesn't last as long.


sytyguy said:
Wes said:
Not overboost, it has an Ultimate Chip. It's running at a solid 15psi.
Click to expand...

You didn't say what setting or version Ultimate you had.........and since a lot of the Ultimate cals have a MAP based fuel shutoff (i.e. Overboost - see 0x03A3 & 0x03A4), I figured it might be worth mentioning. But, if you say it's not, then it's not..........

Otherwise, like Dave said.

Hood
Click to expand...
 
W

Wes

Donating Member
I don't think it's the gas, it was doing it before we put in the newer chip and then it stopped, then recently it started again. Haven't checked on Datamaster for a while, but it feels real strong - like there's very little spark retard. We'll have to check it again.


nick041881 said:
detonation? did it just start doing this? are you sure that you didnt get a bad tank of gas? whats the knock look like with datamaster?
Click to expand...
 
0-60N4

0-60N4

Member
Had the same problem. It was a poor connection of the wires that go to the coil. Check all those connections properlly and give it a tune up on all the ingintion parts until you fix it. This can cause serious damage if it continues.
 
W

Wes

Donating Member
We'll go over the ignition and check connections, probably time for a cap and rotor anyway.

0-60N4 said:
Had the same problem. It was a poor connection of the wires that go to the coil. Check all those connections properlly and give it a tune up on all the ingintion parts until you fix it. This can cause serious damage if it continues.
Click to expand...
 
W

Wes

Donating Member
We tested it today, it IS getting gray (not black) smoke and detonating but it's inconsistent. It runs pretty steady at 5-8 degrees of retard, and then wham detonation.

What's also interesting is that when it detonates, the computer sync with Datamaster quits working - so there's a dead spot in the datamaster file. The first time it happened, it killed the sync with Datamaster and it would not resync. Also the check engine light stayed on, the AC quit working - it was like the computer was in protection mode. We had to restart it to get it to sync again.

The second time it also wouldnt resync and we had to restart it again. The check engine light was not on this time. Then we did some runs on the freeway, one time it did backfire through the intake. It then hit some detonation. It would run like I said around 5-8 degrees retard which is not terrible, but then it would detonate and go to max retard and Datamaster would skip while it was detonating.

This problem with the Datamaster is making me think that maybe there is something wrong with the computer.
 
turbodig

turbodig

Active member
Wes said:
We tested it today, it IS getting gray (not black) smoke and detonating but it's inconsistent. It runs pretty steady at 5-8 degrees of retard, and then wham detonation.

What's also interesting is that when it detonates, the computer sync with Datamaster quits working - so there's a dead spot in the datamaster file. The first time it happened, it killed the sync with Datamaster and it would not resync. Also the check engine light stayed on, the AC quit working - it was like the computer was in protection mode. We had to restart it to get it to sync again.

The second time it also wouldnt resync and we had to restart it again. The check engine light was not on this time. Then we did some runs on the freeway, one time it did backfire through the intake. It then hit some detonation. It would run like I said around 5-8 degrees retard which is not terrible, but then it would detonate and go to max retard and Datamaster would skip while it was detonating.

This problem with the Datamaster is making me think that maybe there is something wrong with the computer.
Click to expand...

Sounds to me like you've got a loose connection in whatever chip
you're running. This is pretty much how the ECM will react when it
'loses' the chip temporarily.

If you've got a socketed memcal (Ultimate, Moates, other), press the
EPROM down a bit to try to reseat it.

Could be something loose internally to the ECM, but that's less likely.

Later,

Dig
 
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