Problem w/Test drive after 1.5 yrs

[PaulRV6]

Finally got the GN registered and took it out for a drive. It did not run very well. If I got into the gas any it would pop and sputter and also backfire. I had stabil in the tank and even filled it up with 93 oct before the drive. I have been occasionally running the car on jackstands and it idles good but as soon as it starts to load it runs terrible. I know i have no data to give out except I watched fuel pressure while accelerating and it does increase when I step on the gas. I am going to see what I can get off of turbolink (no comment) but I was thinking about the fuel filter? Any other suggestions would be helpful. Before I put it away it ran great except for the trans was toast. Thanks
Paul

 

[ScottHeidinger]

If you have fuel pressure I would look at MAF readings next assuming your IAC and TPS are properly set. Do you have a scan master? If not you should be able to verify your IAC and TPS sensor readings from Turbo Link. Take a look at your MAF readings if your IAC and TPS are both set properly.


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[John Larkin]

Could easily be fouled plugs, perhaps a bad connection on a plug wire. Ohm out the coils on the coil pack while you are checking those.

 

[Reapersgbodys]

I would put a good bet on the MAF sensor, but without scanmaster #’s hard to tell.
While car is running, do an old school check, tap on MAF sensor and see if idle changes, if it does, put a MAF Translator and new New MAF sensor, don’t try to get one for our cars at the parts store, they are not calibrated for our cars. Kirban’s does sell the correctly calibrated MAF sensor, but just can’t pull into a parts store and replace it if it goes, with a Translator you can get a replacemenT MAF at any parts store.

 

[PaulRV6]

Ok, I will do more research but to add I installed a 3.0" or 3.5" LTI MAF with translator a few yrs ago. It was working great.
What should I be seeing on the coil packs? THANK YOU

PAUL

 

[John Larkin]

11k - 13k ohms between each pair of coil towers is acceptable. Let the engine be hot first, that ensures you check them under the closest to operating conditions possible. You check them without the car running though, had to say that, no disrespect.

 

[Chuck Leeper]

Add bad grounds, corroded connections, to the list.

 

[No disintegrations]

Finally got the GN registered and took it out for a drive. It did not run very well. If I got into the gas any it would pop and sputter and also backfire. I had stabil in the tank and even filled it up with 93 oct before the drive. I have been occasionally running the car on jackstands and it idles good but as soon as it starts to load it runs terrible. I know i have no data to give out except I watched fuel pressure while accelerating and it does increase when I step on the gas. I am going to see what I can get off of turbolink (no comment) but I was thinking about the fuel filter? Any other suggestions would be helpful. Before I put it away it ran great except for the trans was toast. Thanks
Paul

How much fresh gas vs old gas in the tank? Spark plugs also a likely suspect.

 

[PaulRV6]

Tested the coil packs and they read 10.62, 10.62 and 11.7K.

paul

 

[PaulRV6]

Well I put a new fuel filter in and it seemed like it helped but it is still not right. It still misses or pops when I start to get on it. I checked all the plugs and they are all firing, although they are just a little tan at the tip. I tapped the MAF and didn't change anything. The TPS is working properly. Has new plug wires that I put on last year. It ran good at 65 mph steady state but from a stop it will backfire and pop when it builds a little boost. Not sure what to do next. I still have to get a turbo link file so I can look at it. any other help is appreciated.
Paul

 

[Pronto]

Anyone you can swap the coil with to test?

 

[~JM~]

Try some fresh fuel, plus a can of Sea-Foam.

Change the fuel filter after the next fill-up.

 

[PaulRV6]

Is seafoam a good injector cleaner?
Paul

 

[Coelacanth]

Yes, it's as good as any. Pretty much the same as GM Top Engine Cleaner...follow this procedure:

http://www.gnttype.org/techarea/maintenance/cleaner.html

 

[Gary Durden]

You have not run it for 1.5 years but added Stabil and fresh 93 octane. Stabil will break down also and 1.5 years ia a long time for gas to break down. If you put in fresh gas with bad gas then you contaminate the fresh gas. I would start there as others have mentioned.

 

[PaulRV6]

What is a good replacement spark plugs?
Thanks
Paul

 

[Heskahoka]

You have not run it for 1.5 years but added Stabil and fresh 93 octane. Stabil will break down also and 1.5 years ia a long time for gas to break down. If you put in fresh gas with bad gas then you contaminate the fresh gas. I would start there as others have mentioned.

This. Fresh gas, then spark plugs. Everything else should wait.

Here is how you can drain the tank: https://turbobuick.com/threads/how-to-drain-fuel.244233/

 

[~JM~]

http://www.gnttype.org/maint/basics.html