I have been having some running issues with my Mk IV since I got it back from the shop that worked on it last year. There is a hesitation/flat spot while accelerating, primarily in 2nd and 3rd gear (2,200-2,700 RPM), also sometimes a "chirping" sound from the exhaust while accelerating. That shop has been unable to resolve it. I took the car to another shop that specializes in Mustangs for the past 30 years to have them look at it as the engine is a 302 Mustang V-8 (as we all know!). While I thought I had most of the service history for my car, I do not have the record that shows the installation of the Ford Racing intake and throttle body (see photo). The Mustang specialist also advised that the prior owner installed Air Flow Research (AFR) heads on the car. He claims that these parts have changed/improved the air flow into the engine, which throws the computer off, and the fuel injectors (stock and unchanged) are unable to cope with the increase in air flow. He says this is the cause of the running issues, though I did not have this problem with all of these changes that had been made until the car was returned to me last year from the first shop that worked on it.
After a 3 week stint in the Mustang shop, I got my car back with no modifications having been made, but the mechanic advises that the car should be retrofitted with a mass airflow kit and that the fuel injectors should be changed out for larger ones. Since I got the car back, I now have a hot start issue that it never had before! It seems the issues are mounting...not getting resolved!
I heard of a local engine builder nearer to me who builds race engines and he saw my car yesterday and did not agree with the proposed remedy from the Mustang mechanic. He suggested changing out the standard Mustang ECU (black box) for a programmable computer control called a "Megasquirt" produced by DIYautotune...see link
http://www.diyautotune.com/ This allows the engine to be seen by an external computer and tuned remotely. He has a race prepared Pantera engine set up in his shop where I was able to see the entire engine operations on his laptop computer screen, and he was able to fine tune the engine from his computer which could "talk" to his Megasquirt ECU that was attached to the Pantera Ford V-8. It was quite impressive.
Has anyone had experience with such a programmable ECU in their MK IV and any thoughts on making this modification, replacing the standard Ford ECU? The standard ECU of course is 1986 or so technology (my MK IV is a 1987 car), so I would think the programmable ECU would be better. Any thoughts on the Mustang mechanic's suggestion of the mass airflow sensor addition and changing out the fuel injectors for larger ones instead?
He p[
