Bogging In First Under Full Throttle

[mmarlett]

Hello Forum,

I need your help. I have an 87' GN with 37,000 miles and mods listed in signature.

Recently, within the past 500 miles or 2 months, the car noses over when accelerating under full throttle from a stop. It will take off nicely until about 3-4,000 rpm, then nose over. I noticed on the scanmaster yesterday that when this happened, the Milivolts went to 0 and stayed there a few seconds after lifting from the throttle. The power seems to return going into second and third gear. Knock has been at zero.

In addition, I have adjusted the TT chip fuel settings with no luck. I thought it might be running too rich in first gear.

Since spring, I had to replace the MAF Sensor do to failure of the original. This is a "new refurbished" from Autozone. In addition, I also changed the O2 sensor with one from Autozone.

I would appreciate your thoughts on how I should proceed in diagnosing this issue. What other Scanmaster numbers should I look for, etc,?

Thanks!
Matt

 

[jarredsoon]

you should post all your scan master numbers, and all other info such as recent maintanence or upgrades etc. aslo check the maf numbers when it bogs, at wot they should be steady at 255. Im sure guys on here can figure this out for you.

 

[Razor]

Hello Forum,

Since spring, I had to replace the MAF Sensor do to failure of the original. This is a "new refurbished" from Autozone. In addition, I also changed the O2 sensor with one from Autozone.


Thanks!
Matt

Ding ding.. winner winner..

Only MAF that work are OEM originals or go to the LT1/LS1 translator route.

Remans = trouble 99% of the time.

 

[mmarlett]

Excellent thoughts. How can I confirm that the MAF is the problem? What Scanmaster numbers should I check and what should they say?

Thanks
Matt

 

[mmarlett]

Where is it recomended to get a OEM replacement. Of course I will check the supporting vendors. However, I did not know if there is a recomendation this.

Thanks!
Matt

 

[tzque]

search MAF and you will see alot of recommendations and advice . I have my MAF pipe from Tr custom parts , and then I picked up the translator and got a LS1 Maf from a member on this board . Tr custom parts went above and beyond to help me . I have some advise if you do the change you set up keep all brackets loose to get everything to line up and then tighten everything . It states that in the instructions but I cant read . Mhueffman thank you for your patience .

 

[jarredsoon]

the translator and ls1 maf from a supporting vendor is what you should get. More reliable and superior to the OEM or reman MAF

 

[Razor]

Excellent thoughts. How can I confirm that the MAF is the problem? What Scanmaster numbers should I check and what should they say?

Thanks
Matt

Swap it out with a known good one. Find someone locally to let you borrow theirs.

 

[mmarlett]

Thanks forum members for your advise. I am honored to get advise from the famous Razor!

I did swap out the MAF and also did some tuning on my TT chip. In addition, I recently changed the valve springs. Wow, this was a nice change. I had the stock springs tested for my knowledge and many came back barely holding 60lbs.

These few changes had my TT chip way off on its fuel parameters. The main reason for the bog in first was that it was not getting enough fuel. I made some adjustemnts on the TT chip and it is running much better.

Again, thanks for the help!
Matt