First drive last night....Some minor problems with popping

[BetMinesFaster]

Hey guys, took the first drive last night and it runs pretty strong, but, It has a tendency to pop under boost, sometimes higher boost and sometimes as little as 7 or 8 pounds, usually after the engine has been under boost for a bit, like through first and into second. Sometimes its through the turbo, and sometimes out the tailpipe, the tailpipe tends to be more under heavy boost and throttle. the O2 millivolts were a bit low, so I bumped the fuel pressure a bit and got them to be 750 plus or minus a bit under boost but the popping still occours?

Whats new....
-Turbo Tweak chip
-accufab 70mil wit RJC plenum and plate
-TPS
-Coil pack and Module
-heated O2 sensor kit from caspers
-TA headers
-Lower intake gasket and PCV valve and grommet
-Literally tons of wiring cleanup and all new Autometer Gauges

Whats done to it....
-GN1 aluminam heads
-Champion ported lower intake
-218 cam
-Precision Te63 with HKS racegate
-3" downpipe with 3" exhaust and muffler-preaxle dump
-Bosch Adjutable regulator
-MSD 50lb injectors
-T&D roller rockers
-Built 200 4R with transbrake and non-locking Art Carr 3000 stall
-Large Griffin radiator
-Large external oil and trans cooler
-Large FMIC

Any help on this would be great, Thanks, Ryan

 

[Underboost]

Make sure all of your boots on the intercooler pipes are on good. As well as intake pipe from the maf to the turbo. When you say pop could it also be a fast flutter?

 

[BetMinesFaster]

All connections are good and couplers are new, Definately sounds like a backfire to me!?!? This car is gonna scream once its dialed!!!

 

[BetMinesFaster]

Anyother feedback on this? Most other posts on this topic refer to a bad coil, Just looking for some ideas on where to look??? Has anybody gotten a new coil that was bad before?

 

[turbojd]

What brand coil pack and module are you running on it? some people have had bad luck with some of the aftermarket ign. modules.

 

[BetMinesFaster]

The parts are from Napa, Their Echlin line on the coil and with my history with Napa parts seem to be good parts, however the module they only had the economical part which im not certain of the quality.....

 

[imjoesnuffy]

Sounds similar to a problem I was chasing. Initially the car ran OK and would pop and backfire under heavy boost. Then it became a flutter sound around 10-13 psi. I chased my tail. Replaced the coil with one from Autozone.

It ended up being the coil. The one I bought from Autozone ohmed out at 11.95-12.02, I thought it was fine. Replaced it with an original AC Delco, problem solved. Any scantool or datalogs? My O2 volts were all over the place, when it was happening.

Take your ignition module somewhere to have your ignition module tested. Have them test it 4 or 5 times back to back to heat it up. Testing it once doesn't get it hot enough to really test under load. HTH

 

[BetMinesFaster]

Problem turned out to be #5 Injector breaking up under load, extreme resistance in injector was freaking out the rest of them... Took a bit to find the problem but its fixed! Car is extremely fast and I only have the boost at 15 psi...

 

[Underboost]

Problem turned out to be #5 Injector breaking up under load, extreme resistance in injector was freaking out the rest of them... Took a bit to find the problem but its fixed! Car is extremely fast and I only have the boost at 15 psi...

Cool Go find some mustang's. :biggrin:

 

[GNDriven]

BetMinesfaster,

Can you elaborate on how you found that #5 injector was breaking up under high load? I am interested in how you found that. Thank you

GNDriven

 

[turbobob924]

I too am interested in how you found out about the injector breaking up

 

[Boost231]

+1

 

[TurboMonte 2]

+2 & 3...

 

[BetMinesFaster]

BetMinesfaster,

Can you elaborate on how you found that #5 injector was breaking up under high load? I am interested in how you found that. Thank you

GNDriven

I have a noid light kit with a fiberoptic cable that I can place under a wiper while i drive and monitor the injector pulsing, the flashing is usually bright and very rapid under a load, I used it on all 6 one at a time and noticed that they would get wild and very non rythmic when the popping occoured, but number 5 the noid light would get far dimmer, like a major current draw, at the same time the blm's would be all over, I checked the ohms on them all cold and they were within .1 or .2 of eachother, however warm #5 was nearly half the others! I took it to a local shop and he dissassembled it and said it was shorting out internally and should be replaced..motron 60's and a new chip and it runs like new...

 

[GNDriven]

Great detective work?

You could have replaced those injectors yourself, saved that labor money for future mods.

 

[BlackoutDrunk]

I have a similar problem with popping but the weird thing about it is that, it only makes itself known when the air is cooler. During the warmer months the car never had an issue and about a month ago I had the car out and it was pretty chilly that night. Under heavy boost the car would pop during a WOT blast. I changed the ignition module and it still happend so I was thinking fuel delivery or the maf. My reasoning was that because cold air is more dense more oxygen is getting into engine and the popping was from a lean type condition and a failing fuel injector does make sense now too.

Anyone have anymore ideas of what I can look for? I just got the car over the summer and know the injectors are about 6-7 years old.

 

[at7we2]

(subscribed)

I've been chasing a similar problem for over two years! I thought I had it fixed several times but then the "popping" comes back.

I've replaced or temporarily swapped-out just about everything fuel and ignition related. I've been suspecting an injector problem for the last few months now. But I haven't been able to check it out yet. I recently picked up a DirectScan so I hope that will help me figure out what's going on. Like yours, my car runs awsome when it's not popping.

Glad you got yours sorted out! Good diagnostic work. :biggrin:

Rob

 

[BetMinesFaster]

Great detective work?

You could have replaced those injectors yourself, saved that labor money for future mods.

I did the service myself..I brought just the injector to my dude...was time for some bigger ones anyways!!!

 

[TurboMonte 2]

Great detective work?

Comments/help like this are of zero value--only adds to #'s of posts. OF COURSE, once the problem was diagnosed (with what I would consider GREAT DETECTIVE WORK!--not ?) anyone could come in with a cheap-shot that "coulda replaced inj's yourself"... duh-duh

 

[BetMinesFaster]

Comments/help like this are of zero value--only adds to #'s of posts. OF COURSE, once the problem was diagnosed (with what I would consider GREAT DETECTIVE WORK!--not ?) anyone could come in with a cheap-shot that "coulda replaced inj's yourself"... duh-duh

Haha, Lol!!