DIY PROMDo It Yourself PROM chip burning help. No PROM begging. No PROMs for sale. No commercial exchange. Not a referral service.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
I've been doing a bunch of tuning and data logging over the past year and a half. Recently, every now and then I get a strong hesitation and/or backfire while going from very light throttle to full throttle. It doesn't happen when I hammer it, but when I am somewhat slowly pressing the pedal down.
I took a look at my data logs and found that the MAF voltage reading momentarily drops to "0" when this backfire / hesitation occurs (and then comes back up). Until recently, I've never seen that in the data log (and hadn't encountered the hesitation / backfiring either).
Could this be the beginning of the MAF sensor going bad? There are no loose / worn wires, connections are clean, etc. The MAF is the original from 1987, though I removed the screens and heat fins several years ago (never had any issues until now).
What do you think?
Thanks!
Dan
This ad is not displayed to registered members. Register your free account today and become a member on ThirdGen!
__________________ 1987 Corvette 383 ci small block
It may be the TPS is going out. Sounds strange but there is something that keeps telling me that it is the TPS. Part of it is the slow throttle movement. This reeks of TPS problems.
A bad spot in the TPS can have the ECM thinking that the driver lifted off the throttle. It sees it go from 22% to 0%, the ECM will cut back on the fuel.
It can be tought to test a TPS for bad spots. But it may be worth looking into as they are less expensive then a MAF.
Ok - I'll get a voltmeter on the TPS tomorrow and double check it. The data log does not show any drop at all in TPS voltage though; it seems to be reporting accurately.
Hi, Check out www.c4vettes.com for useful Mass Flow Facts - i hate this MAF sensor problem... my 85 Z28, 5.0L, H.O., TPI gave "no start" problems; then its fine; then no starts; then dies at the intersection, or going up a small grade; then restarts; or, press the pedal down and nothing happens; release pedal, it comes back; or drives choppily at 35-45mph; all with eng ck light on, all code 33! Not solved yet, even nos bosch unit; bought pigtail harness, not arrived yet from tpi-parts, eBay. Good luck!
I've been doing a bunch of tuning and data logging over the past year and a half. Recently, every now and then I get a strong hesitation and/or backfire while going from very light throttle to full throttle. It doesn't happen when I hammer it, but when I am somewhat slowly pressing the pedal down.
I took a look at my data logs and found that the MAF voltage reading momentarily drops to "0" when this backfire / hesitation occurs (and then comes back up). Until recently, I've never seen that in the data log (and hadn't encountered the hesitation / backfiring either).
Could this be the beginning of the MAF sensor going bad? There are no loose / worn wires, connections are clean, etc. The MAF is the original from 1987, though I removed the screens and heat fins several years ago (never had any issues until now).
What do you think?
Thanks!
Dan
Check out the relays, some are better then others.
I use the fan relay replacement for both the maf power and burn off, it is heavier duty and the same price.
