Increased temp after intake swap

[jschmidt250]

I recently swapped the intake manifold on my 93. I installed a newer design from a 2000. I also upgraded the injectors with a set of 0280155703 injectors.

Before the swap the temp never went over 210, even in the summer in SoCal. I am now see temps higher than 210 consistently.

Any thoughts on why the temp would be higher after this swap?

[4.3LXJ]

Fuel mixture would be my first guess. It might be a little lean now with the injector swap. You might want to check timing also.

[jschmidt250]

Fuel mixture would be my first guess. It might be a little lean now with the injector swap. You might want to check timing also.

I was thinking it could be lean as well. I'm going to look into the replacement injectors for the 00. If I remember correctly, they are larger than the 93 replacements.

Thanks

[msmoorenburg]

I am running the 99+ intake with stock injectors (from the 97). I don't have any temp issues.

[jschmidt250]

I'm not overheating, I just notice a higher temp.

I did not change the fuel pressure regulator when I swapped the injectors. If I’m not getting enough pressure to new injectors, that would cause a lean condition.

I think I will put the old injectors in to see if that has any effect, then I‘ll look at a new pressure regulator.

[4.3LXJ]

That probably is the best and cheapest plan. IIRC there is one or two fuel pressure changes over the years, but I don't remember the specifics since I haven't messed with this stuff personally

[msmoorenburg]

That probably is the best and cheapest plan. IIRC there is one or two fuel pressure changes over the years, but I don't remember the specifics since I haven't messed with this stuff personally

I can verify in 97 the fuel pressure regulator was moved to the tank 96 on down was on the rail

97+ fuel pressure at idle is 49.2 psi also cannot drop below 30psi after 5 mins not running

96 on down is 31 psi @ idle
when you remove the fuel pressure regulator vacuum it should go to 39~41


info is from alldata

[denverd1]

Model Year, ...Part #, ...........Colour, .....Fuel Pressure, ...Static Flow,
'87-'90, ........53003956, .........Black, ...........39psi, .................18.6lb/hr
'91-'93, ........33007127, .........Brown, ..........39psi, .................21.0lb/hr
'94-'95, ........53030343, .........Tan, ...............39psi, .................21.0lb/hr
'96-'98, ........53030778, .........Grey, .............49psi, .................23.3lb/hr
'99-'04, ........04854181, .........Blue tip, ........49psi, .................22.5lb/hr
'05-'06, ........53013690AA, ...Brown tip, .....49psi?, ...............23.3lb/hr
from cleggengine.com stroker site

[jschmidt250]

Model Year, ...Part #, ...........Colour, .....Fuel Pressure, ...Static Flow,
'87-'90, ........53003956, .........Black, ...........39psi, .................18.6lb/hr
'91-'93, ........33007127, .........Brown, ..........39psi, .................21.0lb/hr
'94-'95, ........53030343, .........Tan, ...............39psi, .................21.0lb/hr
'96-'98, ........53030778, .........Grey, .............49psi, .................23.3lb/hr
'99-'04, ........04854181, .........Blue tip, ........49psi, .................22.5lb/hr
'05-'06, ........53013690AA, ...Brown tip, .....49psi?, ...............23.3lb/hr
from cleggengine.com stroker site

So it looks like I'm running a fuel regulator and injectors at 39psi/21.0lb/hr. The new intake setup should be running 49psi/22.5lb/hr.

If I understand this correctly, I'm not running enough fuel through the new set up which leans it out and increases the temp.

[4.3LXJ]

Probably so

[denverd1]

sounds like that could be the issue. have you pulled a plug yet?

[Mudderoy]

Well Matt pointed out, due to this post, that the Ford Mustang injectors that I have in my 98 run at 24 lb/hr at 39 psi. My fuel pump is 49 psi. :sign0181:

I've ordered some that run 22ish pounds at 49 psi.

[Cheromaniac]

Model Year, ...Part #, ...........Colour, .....Fuel Pressure, ...Static Flow,
'87-'90, ........53003956, .........Black, ...........39psi, .................18.6lb/hr
'91-'93, ........33007127, .........Brown, ..........39psi, .................21.0lb/hr
'94-'95, ........53030343, .........Tan, ...............39psi, .................21.0lb/hr
'96-'98, ........53030778, .........Grey, .............49psi, .................23.3lb/hr
'99-'04, ........04854181, .........Blue tip, ........49psi, .................22.5lb/hr
'05-'06, ........53013690AA, ...Brown tip, .....49psi?, ...............23.3lb/hr
from cleggengine.com stroker site

They obviously copied that information directly from the Tech Specs page (http://www.jeep4.0performance.4mg.com/tech_specs.html) of my site.
When I did the '01 intake swap nearly 4 years ago, my engine ran lean but I already had a MAP adjuster so tweaking the voltage higher corrected that.
I only saw a small HP/TQ gain but the engine felt peppier at low/medium rpm and the gas mileage improved so I was happy with the results.

[jschmidt250]

After sending the last few months going through and installing a new fan clutch and thermostat, as well as changing the injectors ans adding an adjustable fuel pressure regulator, I was finally tired of dealing with the increased temps and trying figure out how to get them back down by adding new things.

Prior to doing the intake swap I never saw temps over 210, after the swap It ran at around 220.

Yesterday I put the stock intake back on and suddenly the temp stayed below 210.