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-   -   FD hard start & no idle (https://www.rx7club.com/new-member-rx-7-technical-256/fd-hard-start-no-idle-972913/)

coreysvt 10-11-11 04:23 PM

FD hard start & no idle
 
Hi guys, I have a bridgeported 93 FD single turbo. When I got it the IAC(I think, it's on the throttle body close to the firewall) was unplugged so I plugged it up. On the first hard second gear pull I made up to 8000 rpm, the engine stalled when I let off. it will crank and run as long as I keep my foot on the gas. It seems to skip around 2,800 rpm. The plugs and coils are good and I'm getting fuel. I checked the compression with a gauge type tester, and it pulsed evenly at 50 psi(low, I know). the cranking rpms seem slow, however. Every once in awhile, it seems to have a hesitation when crusing at 60 mph. And it stalls out when i turn the AC on. My friends keep saying its the Apex seals. Also when I got it, it would idle at around 24-2500 rpm.

gracer7-rx7 10-11-11 07:28 PM

Engine stall on decel could be the dashpot needs adjustment. Check the 3rd gen FAQ for that procedure - or the FSM which you can download from the FAQ.

You may want to describe how you did your compression test. 3 even pulses of 50 is higher than normal iirc. There is a good thread on compression testing in the 3rd gen fAQ.

Stall when A/C is engaged is probably idle tuning of the PFC. lack of idle tuning and poorly set up.

Who tuned the PFC?

Sgtblue 10-12-11 05:04 AM

Friends say it's the apex seals because that's the only part of the engine they know the name of. If you're getting three even pulses it's probably not.

You might also search/check the regional forum for a rotary shop closest to you that is familiar with FDs.
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coreysvt 10-12-11 04:22 PM

thanks guys. I will adjust the dashpot and let you know if it helps. It does need a tune. I did the compression check on the leading plugs, and held the release valve on the gauge open while my girlfriend cranked it over for 15-20 seconds. it would stay running on its own until i got on it that one time. whats a normal idle rpm for a bridgeport?

coreysvt 10-12-11 08:10 PM

a little while ago I checked the dashpot.It works properly. I played with the idle screw closest to the top of the throttle body for about ten minutes, and now it idles @ 16-1700 rpm and doesn't stall out. took it out and the drivability is greatly improved from when I
got it only a week and a half ago. Thanks for the help!

gracer7-rx7 10-12-11 08:29 PM


Originally Posted by coreysvt (Post 10821649)
thanks guys. I will adjust the dashpot and let you know if it helps. It does need a tune. I did the compression check on the leading plugs, and held the release valve on the gauge open while my girlfriend cranked it over for 15-20 seconds. it would stay running on its own until i got on it that one time. whats a normal idle rpm for a bridgeport?


Depends on how big the bridge is. They generally need a higher idle. idle ain't easy on a bridge port.

Keep an eye on your regional sub-forum to hear about local tuning events. Also check out kantuning.com


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