Dave Farr

Have a Wester's 89 HOT tune and ever since changing to TPI truck has not had the power I expected and on 89oct or even 94oct couldn't get rid of the pinging, timing light show irratic motion of the timing mark around 2000rpm. For the hell of it switched out the 7747 (one year old AC Delco) for a wrecker 7747 and dumped the MSD 6A and Jacobs coil with a stock coil. Problem 95% cured but still have a little bit of ping going on. Plans are to use the 7747 to control trans and dash with a MS2v3 controlling fuel spark and IAC, with a LC1 wideband. I don't burn chips but need hands on tuning and the price is pretty reasonable- considering I am upgrading the processor and O2 sensor as well, couldn't justify the expense of other ecu's. One question is the guy suggests eliminating the EGR for "better power and economy" while still passing emissions, is this true if his tuning is bang on?

RednGold86Z

iTrader: (1)

Well, with mega squirt, you won't be able to properly compensate for the effects of EGR, so you'd have to delete it.

Have you tried reducing the base timing? That's step #1 in getting rid of pinging (without digging into the chip).

Not sure why you're using a 7747 with TPI. It doesn't fire the injectors correctly. Surprized it idles.

Using a timing light with an MSD can cause problems also.

Tuning your own stuff isn't exactly hard, but it's a lot to jump into. mega squirt vs do it yourself prom tuning is a tough debate (simplicity in area X vs simplicity in area Y). I'm all for DIY (but look at my sig, I design and tune and everything for EFI, so go figure). Knowing what the real problem is is half the battle.

Dave Farr

What the heck are you doing in China of all places- you EFI guys should be putting more go fast into old muscle cars here- I know, you have to make a living too

The 350 compression is 9.5:1 using vortec heads on Edelbrock Hi Flow base and runners and ported TB 785cfm, 19pph ford blue tops running 53psi. I think Lyndon W may have been a little aggresive on his 89 HOT tune timing- around 29 deg at 2200rpm I don't know, I do know he tunes alot for max power where I wanted max effiency. Another problem is that at time I had cheap access to 94 oct fuel which is no longer the case and I would think it masked some of the problems. I could send a copy of the chip file for you to look at, he also started from Edelbrocks original tune- which was a real piece of crap- although no reflection on his work.

The TPI is in a 89 k1500 truck (see 7747) and originally was an Edelbrock TBI to MPFI conversion kit and really had good power with their single plane intake, but I always liked the look of TPI- was looking at the HSR but at the time the EGR was an issue and the Holley rep said its a dog until 3500rpm I've been hearing different though- but I already had bought the new intake- the vortec really limits your options. The system had good power and propably would suffice for most people, buts its my biggest vice/hobby and the idle among other issues really bugs me and I can't just drive through emission testing without backing out the timing. And its still has the vortec roller cam.

Frankly I am getting tired of dealing back and forth with the chip even though I was getting the new files via email and burning it local- I think there is no substitute for hands on. The new generation of ecu's are great but still alot of money- the FAST looked really good, and I missed out on ebay for a MOTEC $1200. The local talent pool is very shallow here and by chance found out about this guy who upgrades BMW and Volkwagens for the turbo guys, he was using his own MS version (whatever that is) and a new inexpensive european ecm which is capable of sequential. His price and labour are very reasonable and cheaper than the price of the FAST would be in and tuned. We were discussing installing an adapter harness that would allow the 7747 to control trans lockup, dash, EGR and allow the MS to just look after the timing, fuel, and a LC1 wideband relocated to in front of the cat from the upper manifold- still using 3" single exhaust. This would allow for very little cutting of existing harness, less labor for wiring, MS harness would only go to new O2 and new air temp sensor that never came with the truck- there would also be a narrow band O2 at the manifold for the 7747 just in case.

I always thought that sequential was the top option, he is saying a properly tuned bank to bank is only 1-3% behind sequential. the other computer is about $300 more that would allow for it and he says that he pull signal off the small cap hei- I was told by others that the distributer would have to be extensively reworked/replaced with a dedicated unit for the ecu to see cam timing. Cheers

Dave Farr

Turns out the the MSD superconductors and zip ties don't mix- switch to properly loomed NGK problem gone-runs strong.