i just installed a 3.4l in my 88 Forumla. It has the 3.4 injectors and doesn't idle very well unless the engine has a load. I thought I saw something about changing to a different MAP may help this problem, however I couldn't find anything. Does anyone know if there is a differnt MAP that helps ?

The 2.8 and 3.4 MAP sensors are the same. I don't think there is any difference actually between any of the 2.8 and 3.4 sensors (about 6 months ago I did a post about this, where I compared the part numbers for all the sensors).

I would check your vaccum lines, and your EGR tube. These are good places for leaks to develop during a swap. Just how is it idling anyway?

It's not the 3.4L MAP, It's a MAP from an 89-91 F-body with the 350 V-8. It seems these MAPs work better on the 3.4L's with the Fiero intake set-up. A few people in our local club have had very good success using these.

Orief..........you're a wealth of knowledge!

I would never have thought that the diff between a 2.8 and 3.4 would be enough that a diff MAP sensor would be required. Are you talking about a DOHC? Just curious...LOL.

Phil

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87 FIERO GT 2.8 5spd
0-60 in 6.8 seconds!

quote Originally posted by Oreif: It's not the 3.4L MAP, It's a MAP from an 89-91 F-body with the 350 V-8. It seems these MAPs work better on the 3.4L's with the Fiero intake set-up. A few people in our local club have had very good success using these.

What kind of benefits have they seen? I'm curious now.

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87 GT 3.4 V6 Fiero Automatic

Bump.. Orief? Do you know the difference in the sensors? It was a noticable help to the idle??? Do you have any other details?

PaulV used it on his 3.4L that he had in an 88 that looked like an Indy clone. The Idle was very much improved. It ran smoother and didn't "hunt". (Hunt= idle rpm fluctuates)
There are a few others that have done it. I don't know exactly why the 3.4L with the Fiero intake set-up seems to need it. But I suspect the V-8 version of the MAP is better at reading the vacuum levels and providing a steady signal to the ECM.

(This is for the 3.4L with Fiero intake, Not the DOHC engine)

[This message has been edited by Oreif (edited 03-01-2003).]

Orief...

Is that V8 MAP suitable for boost applications (5-7psi) or do I need a 2-bar MAP from some other car? Do you have a Part Numbers by chance?

Thanks...

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fierosound - 1987 GT - World of Wheels Winner
& Multiple IASCA Stereo Award Winner (click me)