I am buying a RX7 Turbo for a pretty good price. The body is in good condition, however it has a mismatched fender due to someone backing into it (light is also slightly misaligned), as well as damage trim here and there. The main reason I am wanting it is due to almost no rust, something hard to find in Canada (it was originally a Florida car and then wasn't winter driven).

Most problems are cosmetic and easily replaced/repaired, however there are two issues that I am trying to diagnose.

1. The car has trouble starting when warm, it seems to be flooding and the owner had installed a fuel cut to rectify this. From what I read it seems to be dirty injectors?

2. The car had a hesitation issue at 4k+ RPM, and the owner fixed it by wiring a bypass switch on the boost sensor. Is this the infamous hesitation issue? From what I am reading, doing this dumps more fuel into the chamber, and may be cause again by leaky injectors or by improper grounding. Below 3k it runs with no problems. When the switch is flicked on, the boost gauge jumps to max.

Otherwise the car runs normal when you use both fixes, and revs to red line no problem with no white/black smoke.

 

The being hard to start when warm can be leaking fuel injectors. That would be my #1 guess - they have a history of causing this type of sympton.

I also had a similar problem and I looked in the fuel tank and it was loaded with rust. It would start fine when cold but when I drove it some place the rust would get agitated and it caused it to be hard to start. If the car you are looking at has sit for years I would recommend looking in the gas tank.

 

What are the compression numbers. That will tell the story

 

The more and more I read about the hesitation issue, the more I think it's the boost sensor not opening up the secondary injectors. I guess this guy's fix forces them to open, which while wastes fuel.... fixes the problem.

I wonder if the boost gauge he installed could cause the problem (vacuum leak?) or maybe it needs to be reground.

 

first thing to know about every Rx7 turbo, is that they have been pulled apart and monkeyed with since it was new. its not some virginal car that's never been worked on, its been pulled apart 72,000 times and there is a 99% chance that something is assembled incorrectly

1. the hard hot start, it can be injectors, however it can be vacuum leaks; there probably are some. it can also be an incorrectly routed vacuum hose. the common one is to have the fuel pressure regulator on the wrong nipple in the back, so it doesn't see boost. it can also be engine condition.

2. the 4k hesitation could be several things, the misrouted FPR vacuum line being #1. it could also be hitting overboost fuel cut, especially if its got a non stock exhaust. stock boost is about 6.5psi, and fuel cut is only 8.25, so when you put an exhaust on, you fuel cut quickly

3. its a florida car, they rust on the top, and in the roof, so look up.

 

Aside from what's mentioned above, read what Aaroncake has provided on his website:

How To Buy An '86-'92 Turbo RX-7

I followed his guide when I bought my car, and it helped a lot.