Larz

I'm a third gen guy who has the opportunity to buy an 87 in decent shape except for a hesitation problem at high rpm. At low rpm it's fine. What are some possible causes for this? The guy has given up on it, and is willing to sell it to me very cheap. Should I go for it, or could this cost me my first born child?

CyborgRyu

iTrader: (8)

what kind of hesitation?

Larz

He says it's only at WOT. Not sure if it would be a major fix, or if I could make out on this deal. Figured I'd go to the experts.

Larz

Bump

xtremeskier97

About what RPM does this start to happen?

Did he:

change plugs/wires?
fuel filter?
fuel pump?
clean injectors?

If not, then doing those things doesnt cost much and may cure the problem.

Larz

Good to go. Thanks for the advice. Can't bad grounds do the same thing? He says it only happens when he "tries to get on it". He's changed the plugs to oem plugs and wires to some cheapo O'Reilly wires.

torean

check the 5/6 ports?....

xtremeskier97

Yes...check the grounds.

Check www.rotaryresurrection.com for a "DIY how to" on replacing all grounds.

EfiniGirl

If it's a kinda bogging/no power/hesitation above 4-4.5k, then it might be your 5/6 ports...

RotaryEvolution

iTrader: (30)

since you didn't specify if it was a turbo maybe it is just fuel cut? car have any mods?

Larz

No mods. His story has since changed. He says it's gotten worse. It bucks if you give it a decent amount of gas and then levels out. The fuel pump has been changed on it.

torean

what rpm are we talking about?.....under 3800......above 3800.....above 4500?..... stock fuel pump?.....if he gets a walbro on a NA...u can bet that its gonna act whacky.....

Larz

It was an OEM replacement pump. This guy knows dick about modding. He says it's in all rpm ranges. What do you guys mean by 5/6 ports?

torean

5/6 ports is similar to vtec on a honda.....engine opens up additional ports to let in extra air for that added kick similar to vtec

torean

just buy it...u can be sure we can fix anything on a rx7 on this forum

Apathy

to me it sounds like it could be a bad connection on the secondary fuel injectors... you should clean them and make sure that they are clipped in tight... because otherwise you will get scattered gas injections whenever the secondaries kick in making the car bog at high rpm... I know I had the same problem on both my rx7s... if thats not it get new injectors or get yours cleaned... check the ground on the firewall right next to your windshield wiper motor and make sure that it is ok... and finally check your 5/6 ports... if you do all of the above, then you should fix the problem...

Rx7Ridah

iTrader: (8)

well is it a n/a or turbo? that will change some of the suggestions. if someone else worked on it, like the pump changing, it could be installer error. pump could be insufficient. bad grounds are very common, bad connection to the boost sensor if its turbo, also if turbo could be mods that have surpassed the fuel cut off. bad injectors, plugs, wires, connections to the coils. let us know what model and mods?

Larz

No mods. It's NA. How do I check the 5/6 ports?

torean

on the LIM there are these two actulator things that rotates a pin sticking out of the LIM.....from what i read u should be able to push the actulator rod up and down to rotate the pivoting pin.....theres a thread on the 2nd gen archive that explains this in detail......

hmm yeah....imma have to go ahead and tell u that the 5/6 ports are stuck.....if the guy knows nothing about the 7....he probably doesnt know that it should be driven hard every so often...so most likely it was driven under 4k...

Larz

The guy also said he doesn't have secondary injectors. WTF? I thought the basic engine layout would be similar to my 13BREW.

torean

hmm.....how old is the guy?....this is getting interesting

Larz

He's 21. Chevy guy. He broke down today and said he'll sell me the car. We begin negotiations tommorrow.

JamesBong

I'll bet you fix the grounding and replace ALL of the vacuum lines, and it'll run like a charm. He probably dosn't think it has secondary injectors because he can only see two. Tell him the thing is totally fuxed, and you'll take it off his hands for $500 because it'll need a new engine. It's got a blown valve! mwahaha! Or you can be honest and tell 'em it shouldn't be too hard to fix, cause you got connections!

Larz

Which Dirty Pair episode is that avatar from, MR. Bong? Don't recall that one. He doesn't know his Wankel, so hopefully I can get it for 800 or as low as 500. I've had my heart set on something to use for auto x. Was considering a Miata, but I love the rotary too much. Thanks for the crash course on the 2nd gen, guys.