I got a 88 N/A Base model. Right at around 4500rpm my engine has a 1/2 second hesititation of acceleration. Otherwise its runs perfectly...is this normal or what? Seems kinda odd cause I got new spark plugs and I downed a bottle of fuel injector cleaner in it too.

Thanks,
Nima

PS. What kind of gas mileage should I be getting (with brand new spark plugs)? I'm getting about 15mpg in the city....

 

A lot of people get this hesitation at 3800rpms, and its caused by the secondary injectors going online. Your might be related to the same issue, I'm not the sure. The problem is bad grounds. Try adding an 8-10 gauge wire from the negative battery terminal to your chassis somewhere, you can also run a ground from the engine somewhere to the chassis. See if this fixes your problem. BTW, I get 12-15mpg gallon in the city, 20 on the highway, if I'm lucky.

 

I had that absolutely HORRIBLE hesitation that was intermittent in how bad it was but it was always there. I have 3 rx7's, 1 a parts bitch, the other i wrecked but has a strong *** engine, and the third my baby with a bodykit that has the hesitation. I tried ground the pressure sensor to no avail. I also yanked the ECU out of both the other cars and tried them to no avail. I hooked a voltmeter up to the wires that carry the power for the injectors, all were giving me basically ok readings. I replaced the cats which i ended up gutting. It was driving me insane but there was nothing i could do. Then i read on some stupid little website that the grounds from the injectors could be a possible cause and since i was running out of options and ideas i said what the hell i did it. VIOLA!!! it was gone and i had a so much smoother power curve which was great. even if your car isnt hesitating ground the ECU cause Mazda RX-7's have got to have the record the THE WORST grounding job of any car ever built. well thats my 2 cents, hope it helps you out.

88SE
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K&N Filter
Gutted Cats W/Stock mufflers & Y pipe
Body Kit W/New paintjob
Clean inside and out