PDA

View Full Version : Wedge High Idle on TR-7



urchin
04-23-2004, 05:49 PM
My '80 TR-7 Spider has the twin Stromberg carburetors. Over the 19,000 miles I've driven it this year, it's run just fine: great gas mileage [26-29 mpg] at all speeds, starting at -20F and running fine in all warmer seasons. The only "tune-up" I've done is to replace the plugs. When I did, I saw they were clean and worn, but without any build-up.

However, the idle has consistently been high since I purchased the car. It starts up around 1,200 rpm and then when warm, climbs and stays at 1,800 rpm. I've tried adjusting the carb idle screws but nothing changes. The center screw seems to control the throttle linkage rather than idle speed.

What should I do to reduce the idle. Do I have a vacuum leak somewhere - if so, I can't find it. All the emission stuff is still on the car.

Thanks,

Jeff

Izual Angel
04-23-2004, 05:54 PM
Are those rubber flexi mounts cracked at all?

ObiRichKanobi
04-23-2004, 07:23 PM
If your car is/was air conditioned, check to make sure that the "throttle jack" isn't stuck on. That's the little solenoid idle compensator that's supposed to kick on when the A/C is on.

steve99
04-23-2004, 08:38 PM
Urchin, Had the same issue on my 79 last summer. Best way I found to fix it is by eliminating one issue at a time. First, disconnect to throttle cable at the the carb end, this will tell you if it is out of adjustment. Then listen to the carbs, (1/4" vacuum tubing about 3-4' long), shove one end in the carb throat, and the other in your ear, te sounf you hear will tell you if the carbs are adjusted evenly. I also found it was very helpful to adjust each carbs idle speed screw only about 1/4 turn at a time. After each adjustment (with the engine running) rev the engine up and hold it at 2000 - 2500 rpms for a moment to allow the carbs to clear any built up fuel, then listen with the vacuum tube again. Flow meter will do the same thing, also drain your wallet faster.

Steve

urchin
04-24-2004, 08:08 AM
I'll check the rubber mounts for the carbs; I was thinking about them last night.

Rich, where is the "throttle jack" located? My car does have AC, which doesn't work, but it is the original installation.

ObiRichKanobi
04-24-2004, 04:13 PM
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr> Rich, where is the "throttle jack" located? My car does have AC, which doesn't work, but it is the original installation. <hr></blockquote>

It's located on the throttle body on the back of the air plenum. You have to kind of be a contorsionist to see it (British engineers have this sadistic streak graemlins/devilgrin.gif ). However, since I recently purchased a complete FI system for spares, I had a really easy way to take a picture of it for you, which I sent via email. You will find one wire running to it. I disconnected the wire and taped it off, as when mine kicked on, it shot the idle up to about 2500 rpm.